draft-ietf-tsvwg-iana-ports-03.txt   draft-ietf-tsvwg-iana-ports-04.txt 
Transport Area Working Group M. Cotton Transport Area Working Group M. Cotton
Internet-Draft ICANN Internet-Draft ICANN
Updates: 2780, 2782, 4340 L. Eggert Updates: 2780, 2782, 3828, 4340, L. Eggert
(if approved) Nokia 4960 (if approved) Nokia
Intended status: BCP A. Mankin Intended status: BCP J. Touch
Expires: April 29, 2010 Johns Hopkins Univ. Expires: July 15, 2010 USC/ISI
J. Touch
USC/ISI
M. Westerlund M. Westerlund
Ericsson Ericsson
October 26, 2009 January 11, 2010
Internet Assigned Numbers Authority (IANA) Procedures for the Management Internet Assigned Numbers Authority (IANA) Procedures for the Management
of the Transport Protocol Port Number and Service Name Registry of the Transport Protocol Port Number and Service Name Registry
draft-ietf-tsvwg-iana-ports-03 draft-ietf-tsvwg-iana-ports-04
Abstract
This document defines the procedures that the Internet Assigned
Numbers Authority (IANA) uses when handling registration and other
requests related to the transport protocol port number and service
name registry. It also discusses the rationale and principles behind
these procedures and how they facilitate the long-term sustainability
of the registry.
This document updates IANA's procedures by obsoleting Sections 8 and
9.1 of the IANA allocation guidelines [RFC2780], it updates the IANA
allocation procedures for UDP-Lite [RFC3828], DCCP [RFC4340] and SCTP
[RFC4960], it updates the DNS SRV specification [RFC2782] to clarify
what a service name is and how it is registered.
Status of this Memo Status of this Memo
This Internet-Draft is submitted to IETF in full conformance with the This Internet-Draft is submitted to IETF in full conformance with the
provisions of BCP 78 and BCP 79. This document may contain material provisions of BCP 78 and BCP 79.
from IETF Documents or IETF Contributions published or made publicly
available before November 10, 2008. The person(s) controlling the
copyright in some of this material may not have granted the IETF
Trust the right to allow modifications of such material outside the
IETF Standards Process. Without obtaining an adequate license from
the person(s) controlling the copyright in such materials, this
document may not be modified outside the IETF Standards Process, and
derivative works of it may not be created outside the IETF Standards
Process, except to format it for publication as an RFC or to
translate it into languages other than English.
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF), its areas, and its working groups. Note that Task Force (IETF), its areas, and its working groups. Note that
other groups may also distribute working documents as Internet- other groups may also distribute working documents as Internet-
Drafts. Drafts.
Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
The list of current Internet-Drafts can be accessed at The list of current Internet-Drafts can be accessed at
http://www.ietf.org/ietf/1id-abstracts.txt. http://www.ietf.org/ietf/1id-abstracts.txt.
The list of Internet-Draft Shadow Directories can be accessed at The list of Internet-Draft Shadow Directories can be accessed at
http://www.ietf.org/shadow.html. http://www.ietf.org/shadow.html.
This Internet-Draft will expire on April 29, 2010. This Internet-Draft will expire on July 15, 2010.
Copyright Notice Copyright Notice
Copyright (c) 2009 IETF Trust and the persons identified as the Copyright (c) 2010 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents in effect on the date of Provisions Relating to IETF Documents
publication of this document (http://trustee.ietf.org/license-info). (http://trustee.ietf.org/license-info) in effect on the date of
Please review these documents carefully, as they describe your rights publication of this document. Please review these documents
and restrictions with respect to this document. carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must
Abstract include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
This document defines the procedures that the Internet Assigned described in the BSD License.
Numbers Authority (IANA) uses when handling registration and other
requests related to the transport protocol port number and service
name registry. It also discusses the rationale and principles behind
these procedures and how they facilitate the long-term sustainability
of the registry.
This document updates RFC2780 by obsoleting Sections 8 and 9.1 of This document may contain material from IETF Documents or IETF
that RFC, it updates the IANA allocation procedures for DCCP as Contributions published or made publicly available before November
defined in RFC4340, and it updates RFC2782 to clarify what a service 10, 2008. The person(s) controlling the copyright in some of this
name is and how it is registered. material may not have granted the IETF Trust the right to allow
modifications of such material outside the IETF Standards Process.
Without obtaining an adequate license from the person(s) controlling
the copyright in such materials, this document may not be modified
outside the IETF Standards Process, and derivative works of it may
not be created outside the IETF Standards Process, except to format
it for publication as an RFC or to translate it into languages other
than English.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4
2. Motivation . . . . . . . . . . . . . . . . . . . . . . . . . . 5 2. Motivation . . . . . . . . . . . . . . . . . . . . . . . . . . 5
3. Background . . . . . . . . . . . . . . . . . . . . . . . . . . 6 3. Background . . . . . . . . . . . . . . . . . . . . . . . . . . 6
4. Conventions Used in this Document . . . . . . . . . . . . . . 7 4. Conventions Used in this Document . . . . . . . . . . . . . . 7
5. Service Names . . . . . . . . . . . . . . . . . . . . . . . . 7 5. Service Names . . . . . . . . . . . . . . . . . . . . . . . . 7
5.1. Service Name Usage in DNS SRV Records . . . . . . . . . . 8 5.1. Service Name Syntax . . . . . . . . . . . . . . . . . . . 8
6. Port Number Ranges . . . . . . . . . . . . . . . . . . . . . . 8 5.2. Service Name Usage in DNS SRV Records . . . . . . . . . . 9
6.1. Port Numbers and Service Names for Experimentation . . . . 9 6. Port Number Ranges . . . . . . . . . . . . . . . . . . . . . . 10
6.1. Port Numbers and Service Names for Experimentation . . . . 10
7. Principles for Port Number and Service Name Registry 7. Principles for Port Number and Service Name Registry
Management . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Management . . . . . . . . . . . . . . . . . . . . . . . . . . 11
7.1. Past Principles . . . . . . . . . . . . . . . . . . . . . 10 7.1. Past Principles . . . . . . . . . . . . . . . . . . . . . 11
7.2. Updated Principles . . . . . . . . . . . . . . . . . . . . 11 7.2. Updated Principles . . . . . . . . . . . . . . . . . . . . 12
7.3. Variances for Specific Port Number Ranges . . . . . . . . 13 7.3. Variances for Specific Port Number Ranges . . . . . . . . 14
8. IANA Procedures for Managing the Port Number and Service 8. IANA Procedures for Managing the Port Number and Service
Name Registry . . . . . . . . . . . . . . . . . . . . . . . . 14 Name Registry . . . . . . . . . . . . . . . . . . . . . . . . 15
8.1. Port Number and Service Name Registration . . . . . . . . 14 8.1. Port Number and Service Name Registration . . . . . . . . 15
8.2. Port Number and Service Name De-Registration . . . . . . . 16 8.2. Port Number and Service Name De-Registration . . . . . . . 18
8.3. Port Number and Service Name Re-Use . . . . . . . . . . . 16 8.3. Port Number and Service Name Re-Use . . . . . . . . . . . 19
8.4. Port Number and Service Name Revocation . . . . . . . . . 17 8.4. Port Number and Service Name Revocation . . . . . . . . . 19
8.5. Port Number and Service Name Transfers . . . . . . . . . . 18 8.5. Port Number and Service Name Transfers . . . . . . . . . . 20
8.6. Maintenance Issues . . . . . . . . . . . . . . . . . . . . 18 8.6. Maintenance Issues . . . . . . . . . . . . . . . . . . . . 20
9. Security Considerations . . . . . . . . . . . . . . . . . . . 18 9. Security Considerations . . . . . . . . . . . . . . . . . . . 20
10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 19 10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 21
10.1. Service Name Consistency . . . . . . . . . . . . . . . . . 19 10.1. Service Name Consistency . . . . . . . . . . . . . . . . . 21
10.2. Port Numbers for SCTP and DCCP Experimentation . . . . . . 20 10.2. Port Numbers for SCTP and DCCP Experimentation . . . . . . 23
10.3. Updates to DCCP Registries . . . . . . . . . . . . . . . . 21 10.3. Updates to DCCP Registries . . . . . . . . . . . . . . . . 24
11. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 22 11. Contributors . . . . . . . . . . . . . . . . . . . . . . . . . 25
12. References . . . . . . . . . . . . . . . . . . . . . . . . . . 23 12. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 25
12.1. Normative References . . . . . . . . . . . . . . . . . . . 23 13. References . . . . . . . . . . . . . . . . . . . . . . . . . . 26
12.2. Informative References . . . . . . . . . . . . . . . . . . 23 13.1. Normative References . . . . . . . . . . . . . . . . . . . 26
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 25 13.2. Informative References . . . . . . . . . . . . . . . . . . 27
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 28
1. Introduction 1. Introduction
For many years, the allocation and registration of new port number For many years, the allocation and registration of new port number
values and service names for use with the Transmission Control values and service names for use with the Transmission Control
Protocol (TCP) [RFC0793] and the User Datagram Protocol (UDP) Protocol (TCP) [RFC0793] and the User Datagram Protocol (UDP)
[RFC0768] have had less than clear guidelines. New transport [RFC0768] have had less than clear guidelines. New transport
protocols have been added - the Stream Control Transmission Protocol protocols have been added - the Stream Control Transmission Protocol
(SCTP) [RFC4960] and the Datagram Congestion Control Protocol (DCCP) (SCTP) [RFC4960] and the Datagram Congestion Control Protocol (DCCP)
[RFC4342] - and new mechanisms have been developed (DNS SRV records [RFC4342] - and new mechanisms like DNS SRV records [RFC2782] have
[RFC2782]), each with separate registries and separate guidelines. been developed, each with separate registries and separate
The community recognized the need for additional procedures beyond guidelines. The community recognized the need for additional
just assignment; notably modification, revocation, and release. procedures beyond just assignment; notably modification, revocation,
and release.
A key factor of this procedural streamlining is to establish A key factor of this procedural streamlining is to establish
identical registration procedures for all IETF transport protocols. identical registration procedures for all IETF transport protocols.
This document brings the IANA procedures for TCP and UDP in line with This document brings the IANA procedures for TCP and UDP in line with
those already for SCTP and DCCP, resulting in a single process that those for SCTP and DCCP, resulting in a single process that
requesters and IANA follow for all requests for all transport requesters and IANA follow for all requests for all transport
protocols, including those not yet defined. protocols, including those not yet defined.
In addition to detailing the IANA procedures for the initial In addition to detailing the IANA procedures for the initial
assignment of port numbers and service names, this document also assignment of port numbers and service names, this document also
specifies post-assignment procedures that until now have been handled specifies post-assignment procedures that until now have been handled
in an ad hoc manner. These include procedures to de-register a port in an ad hoc manner. These include procedures to de-register a port
number that is no longer in use, to re-use a port number allocated number that is no longer in use, to re-use a port number allocated
for one application that is no longer in use for another application, for one application that is no longer in use for another application,
and procedure by which IANA can unilaterally revoke a prior port and the procedure by which IANA can unilaterally revoke a prior port
number registration. Section 8 discusses the specifics of these number registration. Section 8 discusses the specifics of these
procedures and processes that requesters and IANA follow for all procedures and processes that requesters and IANA follow for all
requests for all current and future transport protocols. requests for all current and future transport protocols.
It is important to note that ownership of registered port numbers and It is important to note that ownership of registered port numbers and
service names remains with IANA. For protocols developed by IETF service names remains with IANA. For protocols developed by IETF
working groups, IANA now also offers a method for the "early" working groups, IANA now also offers a method for the "early"
assignment of port numbers and service names [RFC4020], as described assignment of port numbers and service names [RFC4020], as described
in Section 8.1. in Section 8.1.
This document updates IANA's allocation guidelines [RFC2780] for UDP This document updates IANA's procedures for UDP and TCP port numbers
and TCP port numbers by obsoleting Sections 8 and 9.1 of [RFC2780]. by obsoleting Sections 8 and 9.1 of the IANA allocation guidelines
(Note that different sections of [RFC2780] were updated in February [RFC2780]. (Note that different sections of the IANA allocation
2008 by [RFC5237].) This document also updates the IANA allocation guidelines, relating to the protocol field values in IPv4 header,
procedures for DCCP as defined in [RFC4340]. It updates [RFC2782] to were also updated in February 2008 [RFC5237].) This document also
clarify what a service name is and how it is registered, because updates the IANA allocation procedures for DCCP [RFC4340] and SCTP
[RFC2782] simply refers to [RFC1700] when defining service names, [RFC4960].
which in turn contains now-obsolete copies [RFC3232] of various IANA
registries [PORTREG][PROTSERVREG]. The Lightweight User Datagram Protocol (UDP-Lite) [RFC5237] shares
the port space with UDP. The UDP-Lite specification says: "UDP-Lite
uses the same set of port number values assigned by the IANA for use
by UDP". Thus the update of UDP procedures result in an update also
of the UDP-Lite procedures.
This document also clarify what a service name is and how it is
registered. This will impact the DNS SRV specification, because that
specification merely makes a brief mention that the symbolic names of
services are defined in "Assigned Numbers" [RFC1700], without stating
to which section of that 230-page document it refers. The DNS SRV
specification may have been referring to the list of Port Assignments
(known as /etc/services on Unix), or to the "Protocol And Service
Names" section, or to both, or to some other section. Furthermore,
"Assigned Numbers" is now obsolete [RFC3232] and has now been
replaced by on-line registries [PORTREG][PROTSERVREG]. There are
additional updates and clarifications on how DNS SRV utilize the
Service name registry created in this document in "Clarification of
DNS SRV Owner Names" [I-D.gudmundsson-dnsext-srv-clarify].
2. Motivation 2. Motivation
Information about the registration procedures for the port registry Information about the registration procedures for the port registry
has existed in three locations: the forms for requesting port number has existed in three locations: the forms for requesting port number
registrations on the IANA web site [SYSFORM] [USRFORM], an registrations on the IANA web site [SYSFORM] [USRFORM], an
introductory text section in the file listing the port number introductory text section in the file listing the port number
registrations themselves [PORTREG], and two brief sections of the registrations themselves [PORTREG], and two brief sections of the
IANA Allocation Guidelines [RFC2780]. IANA Allocation Guidelines [RFC2780].
Similarly, the procedures surrounding service names have been Similarly, the procedures surrounding service names have been
historically unclear. Service names were originally created as historically unclear. Service names were originally created as
mnemonic identifiers for port numbers without a well-defined syntax, mnemonic identifiers for port numbers without a well-defined syntax,
beyond the 14-character limit mentioned on the IANA website [SYSFORM] beyond the 14-character limit mentioned on the IANA website [SYSFORM]
[USRFORM]. Even that length limit has not been consistently applied, [USRFORM]. Even that length limit has not been consistently applied,
and some assigned service names are 15 characters long. When service and some assigned service names are 15 characters long. When service
identification via DNS SRV RRs were introduced, the ambiguities in identification via DNS SRV RRs was introduced, the requirement by
the syntactic definition of the service namespace, together with a IANA to only assign service names and port numbers in combination,
requirement by IANA to only assign service names and port numbers in led to the creation of an ad hoc service name registry outside of the
combination, led to the creation of an ad hoc service name registry control of IANA [SRVREG].
outside of the control of IANA [SRVREG].
It has also been historically unclear if the "name" entries
registered in the "Protocol and Service Names Registry" [PROTSERVREG]
can be used as service names. [RFC0952] defines the names in that
registry as either service names or protocol names. It is likely
that these names has been interpreted as being valid service names
and consequently have been used, e.g., in SRV records. This
motivates why this document merges the 166 protocol and service names
defined in that registry into the port number registry [PORTREG].
This document aggregates all this scattered information into a single This document aggregates all this scattered information into a single
reference that aligns and clearly defines the management procedures reference that aligns and clearly defines the management procedures
for both port numbers and service names. It gives more detailed for both port numbers and service names. It gives more detailed
guidance to prospective requesters of ports and service names than guidance to prospective requesters of ports and service names than
the existing documentation, and it streamlines the IANA procedures the existing documentation, and it streamlines the IANA procedures
for the management of the registry, so that management requests can for the management of the registry, so that management requests can
complete in a timely manner. complete in a timely manner.
This document defines rules for registration of service names without This document defines rules for registration of service names without
associated port numbers, for such usages as DNS SRV records, which associated port numbers, for such usages as DNS SRV records
was not possible under the previous IANA procedures. These new [RFC2782], which was not possible under the previous IANA procedures.
procedures also merge service name registrations from the non-IANA The document also merges service name registrations from the non-IANA
"ad hoc" registry [SRVREG] and from the the IANA "Protocol and ad hoc registry [SRVREG] and from the the IANA "Protocol and Service
Service Names" registry [PROTSERVREG] into the IANA "Port and Service Names" registry [PROTSERVREG] into the IANA "Port and Service Name"
Name" registry [PORTREG], which from here on is the single registry [PORTREG], which from here on is the single authoritative
authoritative registry for service names and port numbers. registry for service names and port numbers.
An additional purpose of this document is to describe the principles An additional purpose of this document is to describe the principles
that guide the IETF and IANA in their role as the long-term joint that guide the IETF and IANA in their role as the long-term joint
stewards of the port number registry. TCP and UDP have been a stewards of the port number registry. TCP and UDP have been a
remarkable success over the last decades. Thousands of applications remarkable success over the last decades. Thousands of applications
and application-level protocols have registered ports and service and application-level protocols have registered ports and service
names for their use, and there is every reason to believe that this names for their use, and there is every reason to believe that this
trend will continue into the future. It is hence extremely important trend will continue into the future. It is hence extremely important
that management of the registry follow principles that ensure its that management of the registry follow principles that ensure its
long-term usefulness as a shared resource. Section 7 discusses these long-term usefulness as a shared resource. Section 7 discusses these
skipping to change at page 6, line 37 skipping to change at page 6, line 46
the concept of ports for their communication sessions and use 16-bit the concept of ports for their communication sessions and use 16-bit
port numbers in the same way as TCP and UDP (and UDP-Lite [RFC3828], port numbers in the same way as TCP and UDP (and UDP-Lite [RFC3828],
a variant of UDP). a variant of UDP).
Port numbers are the original and most widely used means for Port numbers are the original and most widely used means for
application and service identification on the Internet. Ports are application and service identification on the Internet. Ports are
16-bit numbers, and the combination of source and destination port 16-bit numbers, and the combination of source and destination port
numbers together with the IP addresses of the communicating end numbers together with the IP addresses of the communicating end
systems uniquely identifies a session of a given transport protocol. systems uniquely identifies a session of a given transport protocol.
Port numbers are also known by their corresponding service names such Port numbers are also known by their corresponding service names such
as "telnet" for port number 23 and both "http" and "www" for port as "telnet" for port number 23 and "http" (and the "www" alias) for
number 80. port number 80.
Hosts running services, hosts accessing services on other hosts, and Hosts running services, hosts accessing services on other hosts, and
intermediate devices (such as firewalls and NATs) that restrict intermediate devices (such as firewalls and NATs) that restrict
services need to agree on which service corresponds to a particular services need to agree on which service corresponds to a particular
destination port. Although this is ultimately a local decision with destination port. Although this is ultimately a local decision with
meaning only between the endpoints of a connection, most Internet meaning only between the endpoints of a connection, it is common for
components use a single, shared view of this association, provided by many services to have a default port upon which those servers usually
the Internet Assigned Numbers Authority (IANA) through the port listen, when possible, and these ports are recorded by the Internet
number registry [PORTREG]. Assigned Numbers Authority (IANA) through the port number registry
[PORTREG].
Over time, the assumption that a particular port number necessarily Over time, the assumption that a particular port number necessarily
implies a particular service may become less true. For example, implies a particular service may become less true. For example,
multiple instances of the same service can run on different ports on multiple instances of the same service on the same host cannot
the same host, or NATs that support port mapping or registration generally listen on the same port, and multiple hosts behind the same
[I-D.cheshire-nat-pmp][UPnP] need to offer service instances using NAT gateway cannot all have a mapping for the same port on the
the same port on several internal hosts available to the public external side of the NAT gateway, whether using static port mappings
Internet on different ports. This document assumes, however, that configured by hand by the user, or dynamic port mappings configured
ports are most often used in a conventional manner - where endpoints automatically using a port mapping protocol NAT Port Mapping Protocol
and intermediate devices all share the common view of the IANA port (NAT-PMP) [I-D.cheshire-nat-pmp] or Internet Gateway Device (IGD)
number registry. [IGD].
Applications either use numeric port numbers directly, look up port Applications either use numeric port numbers directly, look up port
numbers based on service names via system calls such as numbers based on service names via system calls such as
getservbyname() on UNIX, look up port numbers by performing queries getservbyname() on UNIX, look up port numbers by performing queries
for DNS SRV records [RFC2782][I-D.cheshire-dnsext-dns-sd] or for DNS SRV records [RFC2782][I-D.cheshire-dnsext-dns-sd] or
determine port numbers in a variety of other ways [RFC1078]. determine port numbers in a variety of other ways like the TCP Port
Service Multiplexer (TCPMUX) [RFC1078].
Designers of applications and application-level protocols may apply Designers of applications and application-level protocols may apply
to IANA for an assigned port number and service name for a specific to IANA for an assigned port number and service name for a specific
application, and may - after successful registration - assume that no application, and may - after successful registration - assume that no
other application will use that port number and service name for its other application will use that port number or service name for its
communication sessions. Alternatively, application designers may communication sessions. Alternatively, application designers may
also only ask for an assigned service name, if their application does also ask for only an assigned service name, if their application does
not require a fixed port number. The latter alternative is not require a fixed port number. The latter alternative is
encouraged when possible, in order to conserve the more limited port encouraged when possible, in order to conserve the more limited port
number space. This includes, for example, applications that use DNS number space. This includes, for example, applications that use DNS
SRV records to look up port numbers at runtime, or transports that SRV records to look up port numbers at runtime.
use service names not coupled to port numbers, e.g., TCP portnames
[I-D.touch-tcp-portnames].
4. Conventions Used in this Document 4. Conventions Used in this Document
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in BCP 14, RFC 2119 document are to be interpreted as described in RFC 2119 [RFC2119].
[RFC2119].
5. Service Names 5. Service Names
Service names are the unique key in the Port and Service Name Service names are the unique key in the Port and Service Name
registry. This unique symbolic name for a service may also be used registry. This unique symbolic name for a service may also be used
for other purposes, such as DNS SRV records [RFC2782]. Within the for other purposes, such as in DNS SRV records [RFC2782]. Within the
registry, this unique key ensures that different services can be registry, this unique key ensures that different services can be
unambiguously distinguished, thus preventing name collisions and unambiguously distinguished, thus preventing name collisions and
avoiding confusion about who is the registration owner of a avoiding confusion about who is the administrative contact for a
particular entry. particular entry.
For each service name, there may exist zero or more associated port For each service name, there may exist zero or more associated port
number assignments. A port number assignment associated with a number assignments. A port number assignment associated with a
service name contains the transport protocol, port number and service name contains the transport protocol, port number and
possibly additional data, such as a DCCP service code. There may be possibly additional data, such as a DCCP service code.
more than one service name associated with a particular transport
protocol and port. This SHOULD only occur when all such service There may be more than one service name associated with a particular
names are aliases for the same service, such as with "www" and transport protocol and port. This SHOULD only occur when all such
"http". service names are aliases for the same service, such as with "http"
and "www". In such cases, one of the service names MUST be
designated primary, for use with mechanisms such as DNS SRV Records
[RFC2782], and the others MUST be designated as aliases of the
primary service name. This is necessary so that all clients and
servers using a service discovery mechanism use a consistent name by
which to refer to a given service. Otherwise, if a server were to
advertise that it supports the "www" service, and a client were to
seek instances of the "http" service, that client would fail to
discover that server, defeating the purpose of having a service
discovery mechanism.
Service names are assigned on a "first come, first served" basis, as Service names are assigned on a "first come, first served" basis, as
described in Section 8.1. Names should be brief and informative, described in Section 8.1. Names should be brief and informative,
avoiding words or abbreviations that are redundant in the context of avoiding words or abbreviations that are redundant in the context of
the registry (e.g., "port", "service", "protocol", etc.) Names the registry (e.g., "port", "service", "protocol", etc.) Names
referring to discovery services, e.g., using multicast or broadcast referring to discovery services, e.g., using multicast or broadcast
to identify endpoints capable of a given service, SHOULD use an to identify endpoints capable of a given service, SHOULD use an
easily identifiable suffix (e.g., "-disc"). easily identifiable suffix (e.g., "-disc").
5.1. Service Name Usage in DNS SRV Records 5.1. Service Name Syntax
[RFC2782] defines SRV records for the DNS system. One part of the Valid service names MUST contain only these US-ASCII [ANSI.X3-4.1986]
DNS name of an SRV record includes what is called "SERVICE", i.e., a characters: letters from A to Z and a to z, digits from 0 to 9, and
symbolic name for the service. This document updates [RFC2782] in hyphens ("-", ASCII 0x2D or decimal 45). They MUST be at least one
order to clarify that the symbolic name ("SERVICE") SHALL only be a character and no more than fifteen characters long, MUST NOT begin or
service name as defined in this document that has been registered end with a hyphen, and MUST NOT consist of only digits (in order to
with IANA and recorded in the port number and service name registry be distinguishable from port numbers, which are typically written as
[PORTREG]. This to ensure that only a single registry exist and name all digits).
collisions can be more easily avoided in the future.
The service name syntax MAY be used to validate a service name
string, but MUST NOT be used for any other purpose (e.g.,
delineation). Any system that includes a service name inside a
longer string is itself responsible for delineating the service name.
Such systems MUST NOT rely on the syntax of a service name alone for
such delineation.
The syntax defined in ABNF [RFC5234]:
SERVICE-NAME = ( ALPHA / *( [HYPHEN] ALPHANUM ) )
/ (1*DIGIT ( (HYPHEN ALPHANUM) | ALPHA) *([HYPHEN] ALPHANUM) )
ALPHANUM = ALPHA | DIGIT ; A-Z, a-z, 0-9
HYPHEN = %x2d ; "-"
ALPHA = <See RFC 5234>
DIGIT = <See RFC 5234>
5.2. Service Name Usage in DNS SRV Records
The DNS SRV specification [RFC2782] requests that the Service Label
part of the owner name of DNS SRV records includes a "Service"
element, defined to be "the symbolic name of the desired service",
but did not state precisely which part of the IANA database (i.e.
STD 2 when RFC 2782 was written) serves as a registry for standard
service names.
This document clarifies that the Service Label MUST be a service name
as defined herein. The service name SHOULD be registered with IANA
and recorded in the Service Names and Port Numbers registry
[PORTREG]. This is needed to ensure that only a single registry of
Service Names exists and name collisions can be avoided in the
future.
The details of the use of Service Names from [PORTREG] in SRV Service
Labels are specified in [RFC2782] and the documents updating or
replacing that specification (see the companion document
[I-D.gudmundsson-dnsext-srv-clarify] for more information).
The details of how applications make use of DNS SRV should be
specified in the documentation set of the application/service. In
the absense of such specification, prospective clients of a given
service should not assume the existence of SRV RRs for this service
or, if they have indications that this will be the case (e.g., by
configuration), must assume the unextended naming scheme from
[RFC2782] for service discovery with DNS SRV, i.e., the Service Label
is constructed from the Service Name registered in [PORTREG] by
prepending a single underscore character ("_").
6. Port Number Ranges 6. Port Number Ranges
TCP, UDP (and UDP-Lite), SCTP and DCCP use 16-bit namespaces for TCP, UDP, UDP-Lite, SCTP and DCCP use 16-bit namespaces for their
their port number registries. The port registries for all these port number registries. The port registries for all these transport
transport protocols are subdivided into three ranges of numbers, and protocols are subdivided into three ranges of numbers, and
Section 7.3 describes the IANA procedures for each range in detail: Section 7.3 describes the IANA procedures for each range in detail:
o the Well Known Ports, also known as the System Ports, from 0-1023 o the Well Known Ports, also known as the System Ports, from 0-1023
(assigned by IANA) (assigned by IANA)
o the Registered Ports, also known as the User Ports, from 1024- o the Registered Ports, also known as the User Ports, from 1024-
49151 (assigned by IANA) 49151 (assigned by IANA)
o the Dynamic Ports, also known as the Private Ports, from 49152- o the Dynamic Ports, also known as the Private Ports, from 49152-
65535 (never assigned) 65535 (never assigned)
skipping to change at page 10, line 28 skipping to change at page 11, line 48
year, and has remained linear for the past 8 years. At that rate, if year, and has remained linear for the past 8 years. At that rate, if
similar conservation continues, this resource will sustain another 85 similar conservation continues, this resource will sustain another 85
years of assignment - without the need to resort to reassignment of years of assignment - without the need to resort to reassignment of
released values or revocation. Note that the namespace available for released values or revocation. Note that the namespace available for
service names is even larger, which allows for a simpler management service names is even larger, which allows for a simpler management
procedures. procedures.
7.1. Past Principles 7.1. Past Principles
Before the publication of this document, the principles of port Before the publication of this document, the principles of port
number and service name management followed a few mostly undocumented number and service name management followed a few mostly-undocumented
guidelines. They are recorded here for historical purposes, and this guidelines. They are recorded here for historical purposes, and this
document updates them in Section 7.2. These principles were: document updates them in Section 7.2. These principles were:
o TCP and UDP ports were simultaneously allocated when either was o TCP and UDP ports were simultaneously allocated when either was
requested requested
o Port numbers were the primary allocation; service names were o Port numbers were the primary allocation; service names were
informative only, and did not have a well-defined syntax informative only, and did not have a well-defined syntax
o Port numbers were conserved informally, and sometimes o Port numbers were conserved informally, and sometimes
inconsistently (e.g., some services were allocated ranges of many inconsistently (e.g., some services were allocated ranges of many
port numbers even where not strictly necessary) port numbers even where not strictly necessary)
o SCTP and DCCP port number and service name registries were managed o SCTP and DCCP port number and service name registries were managed
separately from the TCP/UDP registries separately from the TCP/UDP registries
o Service names could not be assigned in the ports registry without o Service names could not be assigned in the ports registry without
assigning a corresponding port number at the same time assigning a corresponding port number at the same time
This document attempts to document, clarify and align these This document clarifies and aligns these guidelines in order to more
guidelines in order to more conservatively manage the limited conservatively manage the limited remaining port number space and to
remaining port number space and to enable and promote the use of enable and promote the use of service names for service
service names for service identification without associated port identification without associated port numbers, where possible.
numbers, where possible.
7.2. Updated Principles 7.2. Updated Principles
This section summarizes the basic principles by which IANA attempts This section summarizes the basic principles by which IANA handles
to conserve the port number space. This description is intended to the Port and Service Name registry, and attempts to conserve the port
inform applicants requesting port numbers. IANA decisions are not number space. This description is intended to inform applicants
requesting service names and port numbers. IANA decisions are not
required to be bound to these principles, however; other factors may required to be bound to these principles, however; other factors may
come into play, and exceptions may occur where deemed in the best come into play, and exceptions may occur where deemed in the best
interest of the Internet. interest of the Internet.
IANA will begin assigning service names that do not request a
corresponding port number allocation under a simple "First Come,
First Served" policy [RFC5226]. IANA MAY, at its discretion, refer
service name requests to "Expert Review" in cases of mass
registrations or other situations where IANA believes expert review
is advisable.
The basic principle of port number registry management is to conserve The basic principle of port number registry management is to conserve
use of the port space where possible. Extensions to support larger use of the port space where possible. Extensions to support larger
port number spaces would require changing many core protocols of the port number spaces would require changing many core protocols of the
current Internet in a way that would not be backward compatible and current Internet in a way that would not be backward compatible and
interfere with both current and legacy applications. interfere with both current and legacy applications. To help ensure
this conservation the policy for any registration request for port
number allocations uses the "Expert Review" policy [RFC5226].
Conservation of the port number space recognizes that because this Conservation of the port number space is required because this space
space is a limited resource, applications are expected to participate is a limited resource, applications are expected to participate in
in the traffic demultiplexing process where feasible. The port the traffic demultiplexing process where feasible. The port numbers
numbers are expected to encode as little information as possible that are expected to encode as little information as possible that will
will still enable an application to perform further demultiplexing by still enable an application to perform further demultiplexing by
itself. In particular: itself. In particular:
o IANA will allocate only one assigned port number per service or o IANA will allocate only one assigned port number per service or
application application
o IANA will allocate only one assigned port number for all versions o IANA will allocate only one assigned port number for all versions
of a service (e.g., running the service with or without a security of a service (e.g., running the service with or without a security
mechanism, or for updated variants of a service) mechanism, or for updated variants of a service)
o IANA will allocate only one assigned port number for all different o IANA will allocate only one assigned port number for all different
types of devices using or participating in the same service types of device using or participating in the same service
o IANA will allocate port numbers only for the transport protocols o IANA will allocate port numbers only for the transport protocol(s)
explicitly named in an registration request (if any) explicitly named in an registration request
o IANA may recover unused port numbers, via the new procedures of o IANA may recover unused port numbers, via the new procedures of
de-registration, revocation, and transfer de-registration, revocation, and transfer
o IANA may begin assigning service names that do not request a
corresponding port number allocation under a simple "First Come,
First Served" policy [RFC5226] (assignments involving port numbers
still require "Expert Review")
A given service is expected to further demultiplex messages where A given service is expected to further demultiplex messages where
possible. For example, applications and protocols are expected to possible. For example, applications and protocols are expected to
include in-band version information, so that future versions of the include in-band version information, so that future versions of the
application or protocol can share the same allocated port. application or protocol can share the same allocated port.
Applications and protocols are also expected to be able to Applications and protocols are also expected to be able to
efficiently use a single allocated port for multiple sessions, either efficiently use a single allocated port for multiple sessions, either
by demultiplexing multiple streams within one port, or using the by demultiplexing multiple streams within one port, or using the
allocated port to coordinate using dynamic ports for subsequent allocated port to coordinate using dynamic ports for subsequent
exchanges (e.g., in the spirit of FTP [RFC0959]). exchanges (e.g., in the spirit of FTP [RFC0959]).
skipping to change at page 12, line 20 skipping to change at page 13, line 46
o as endpoint process identifiers o as endpoint process identifiers
o as application protocol identifiers o as application protocol identifiers
o for firewall filtering purposes o for firewall filtering purposes
The process and protocol identifier use suggests that anything a The process and protocol identifier use suggests that anything a
single process can demultiplex, or that can be encoded into a single single process can demultiplex, or that can be encoded into a single
protocol, should be. The firewall filtering use suggests that some protocol, should be. The firewall filtering use suggests that some
uses that could be de-multiplexed or encoded must be separated to uses that could be multiplexed or encoded must be separated to allow
allow for firewall management. Note that this latter use is much for firewall management. Note that this latter use is much less
less sound, because port numbers have meaning only for the two sound, because port numbers have meaning only for the two endpoints
endpoints involved in a connection, and drawing conclusions about the involved in a connection, and drawing conclusions about the service
service that generated a given flow based on observed port numbers is that generated a given flow based on observed port numbers is not
inherently problematic. Further, previous separation of protocol always reliable. Further, previous separation of protocol variants
variants based on security capabilities (e.g., HTTP on port 80 vs. based on security capabilities (e.g., HTTP on port 80 vs. HTTPS on
HTTPS on port 443) is not recommended for new protocols, because all port 443) is not recommended for new protocols, because all should be
should be security-capable and capable of negotiating the use of security-capable and capable of negotiating the use of security in-
security in-band. band.
IANA will begin assigning protocol numbers only for those transport IANA will begin assigning protocol numbers for only those transport
protocols explicitly included in a registration request. This ends protocols explicitly included in a registration request. This ends
the long-standing practice of automatically assigning a port number the long-standing practice of automatically assigning a port number
to an application for both TCP and a UDP, even if the request is only to an application for both TCP and a UDP, even if the request is for
for one of these transport protocols. The new allocation procedure only one of these transport protocols. The new allocation procedure
conserves resources by only allocating a port number to an conserves resources by allocating a port number to an application for
application for those transport protocols (TCP, UDP, SCTP and/or only those transport protocols (TCP, UDP, SCTP and/or DCCP) it
DCCP) it actually uses. The port number will be marked as Reserved - actually uses. The port number will be marked as Reserved - instead
instead of Assigned - in the port number registries of the other of Assigned - in the port number registries of the other transport
transport protocols. When applications start supporting the use of protocols. When applications start supporting the use of some of
some of those additional transport protocols, their implementors MUST those additional transport protocols, their implementors MUST request
request IANA to convert the reservation into an assignment. An IANA to convert the reservation into an assignment. An application
application MUST NOT assume that it can use a port number assigned to MUST NOT assume that it can use a port number assigned to it for use
it for use with one transport protocol with another transport with one transport protocol with another transport protocol without
protocol without asking IANA to convert the reservation into an asking IANA to convert the reservation into an assignment.
assignment.
When the available pool of unassigned address has run out in a port
range, it will be necessary for IANA to consider the Reserved ports
for assignment. This is part of the motivation to not automatically
assigning ports for other transport protocols than the requested
ones. This will allow more ports to be available for assignment at
that point. It also shows the importance to register the transport
protocols that are in fact used.
Conservation of port numbers is improved by procedures that allow Conservation of port numbers is improved by procedures that allow
previously allocated port numbers to become Unassigned, either previously allocated port numbers to become Unassigned, either
through de-registration or through revocation, and by a procedure through de-registration or through revocation, and by a procedure
that lets application designers transfer an allocated but unused port that lets application designers transfer an allocated but unused port
number to a new application. Section 8 describes these procedures, number to a new application. Section 8 describes these procedures,
which so far were undocumented. Port number conservation is also which so far were undocumented. Port number conservation is also
improved by recommending that applications that do not require an improved by recommending that applications that do not require an
allocated port, e.g., because they can use service-name-based allocated port chose this option and register only a service name.
lookups, chose this option and only register a service name.
7.3. Variances for Specific Port Number Ranges 7.3. Variances for Specific Port Number Ranges
Section 6 describes the different port number ranges. It is Section 6 describes the different port number ranges. It is
important to note that IANA applies slightly different procedures important to note that IANA applies slightly different procedures
when managing the different ranges of the port number registry: when managing the different ranges of the port number registry:
o Ports in the Dynamic Ports range (49152-65535) have been o Ports in the Dynamic Ports range (49152-65535) have been
specifically set aside for local and dynamic use and cannot be specifically set aside for local and dynamic use and cannot be
registered through IANA. Applications may simply use them for registered through IANA. Applications may simply use them for
skipping to change at page 14, line 26 skipping to change at page 16, line 6
Registration refers to the allocation of port numbers or service Registration refers to the allocation of port numbers or service
names to applicants. All such registrations are made from port names to applicants. All such registrations are made from port
numbers or service names that are Unassigned or Reserved at the time numbers or service names that are Unassigned or Reserved at the time
of the allocation. Unassigned numbers and names are allocated as of the allocation. Unassigned numbers and names are allocated as
needed, and without further explanation. Reserved numbers and names needed, and without further explanation. Reserved numbers and names
are assigned only after review by IANA and the IETF, and are are assigned only after review by IANA and the IETF, and are
accompanied by a statement explaining the reason a Reserved number or accompanied by a statement explaining the reason a Reserved number or
name is appropriate for this action. name is appropriate for this action.
When a registration for one or more (but not all) transport protocols When a registration for one or more transport protocols is approved,
is approved, the port number for the non-requested transport the port number for any non-requested transport protocol(s) will be
protocol(s) will be marked as Reserved. IANA SHOULD NOT assign that marked as Reserved. IANA SHOULD NOT assign that port number to any
port number to any other application or service until no other port other application or service until no other port numbers remain
numbers remain Unassigned in the requested range. The current Unassigned in the requested range. The current administrative
registration owner of a port number MAY register these Reserved port contact for a port number MAY register these Reserved port numbers
numbers for other transport protocols when needed. for other transport protocols when needed.
Service names, on the other hand, are not tied to a specific Service names, on the other hand, are not tied to a specific
transport protocol, and registration requests for only a service name transport protocol, and registration requests for only a service name
(but not a port number) allocate that service name for use with all (but not a port number) allocate that service name for use with all
transport protocols. transport protocols.
A port number or service name registration consists of the following A port number or service name registration request contains some or
information: all of the following information:
o Registration Owner: Name and email address of the owner of the Registration Administrative Contact (REQUIRED)
registration. This is REQUIRED. For registrations done through Registration Technical Contact (REQUIRED)
IETF-published RFCs, the registration ownership will belong to the Service Name (REQUIRED)
IETF and not the technical contact persons. Port Number (OPTIONAL)
Transport Protocol(s) (REQUIRED if port number requested)
Service Code (only REQUIRED for DCCP)
Description (REQUIRED)
Reference (REQUIRED)
o Registration Administrative Contact: Name and email address of the
administrative contact for the registration. This is REQUIRED.
The name of the administrative contact identifies the
organization, company, or individual who is responsible for the
registration. Registrations done through IETF-published RFCs, the
administrative contact will be the IETF and not the technical
contact persons.
o Registration Technical Contact: Name and email address of the o Registration Technical Contact: Name and email address of the
technical contact person for the registration. This is REQUIRED. technical contact person for the registration. This is REQUIRED.
For individuals, this is the same as the Registration Owner; for
organizations, this is a point of contact at that organization. For individuals, this is the same as the Registration
Additional address information MAY be provided. For registrations Administrative Contact; for organizations, this is a point of
done through IETF-published RFCs, one or more technical contact contact at that organization. Additional address information MAY
persons SHALL be provided. be provided. For registrations done through IETF-published RFCs,
one or more technical contact persons SHALL be provided.
o Service Name: A desired unique service name for the service o Service Name: A desired unique service name for the service
associated with the registration request MUST be provided, for use associated with the registration request MUST be provided, for use
in various service selection and discovery mechanisms (including, in various service selection and discovery mechanisms (including,
but not limited to, DNS SRV records [RFC2782]). Valid service but not limited to, DNS SRV records [RFC2782]). The name MUST be
names MUST only contain these US-ASCII [ANSI.X3-4.1986] compliant with the syntax defined in Section 5.1. In order to be
characters: letters from A to Z, digits from 0 to 9, and hyphens unique, they MUST NOT be identical to any currently registered
("-", ASCII 0x2D or decimal 45). They MUST be at least one service names in the IANA registry [PORTREG]. Service names are
character and no more than fifteen characters long, MUST NOT begin case-insensitive; they may be provided and entered into the
or end with a hyphen, and MUST NOT consist of only digits (in registry with mixed case (e.g., for clarity), but for the purposes
order to be distinguishable from port numbers, which are typically of comparison, the case is ignored.
written as all digits). In order to be unique, they MUST NOT be
identical to any currently registered service names in the IANA
registry [PORTREG]. Service names are case-insensitive; they may
be provided and entered into the registry with mixed case (e.g.,
for clarity), but for the purposes of comparison, the case is
ignored.
o Port Number: If assignment of port number(s) is desired, either o Port Number: If assignment of a port number is desired, either the
the currently Unassigned port number(s) the requester suggests for currently Unassigned port number the requester suggests for
allocation or the tag "ANY" MUST be provided. If only a service allocation, or the text "ANY", MUST be provided. If only a
name is to be assigned, this field MUST be empty. If specific service name is to be assigned, this field MUST be empty. If a
port numbers are requested, IANA is encouraged to allocate the specific port number is requested, IANA is encouraged to allocate
suggested numbers. If the tag "ANY" is specified, IANA will the requested number. If the text "ANY" is specified, IANA will
choose a suitable number from the Registered Ports range. Note choose a suitable number from the Registered Ports range. Note
that the applicant MUST NOT use the suggested ports prior to the that the applicant MUST NOT use the requested port prior to the
completion of the registration. completion of the registration.
o Transport Protocol: The transport protocol(s) for which the o Transport Protocol(s): If assignment of a port number is desired,
allocation is requested MUST be provided. This field is currently the transport protocol(s) for which the allocation is requested
limited to one or more of TCP, UDP, SCTP, and DCCP. MUST be provided. This field is currently limited to one or more
of TCP, UDP, SCTP, and DCCP.
o Service Code: A desired unique service code for the service o Service Code: The request MUST include a desired unique DCCP
associated with the registration request. Service codes are service code [RFC5595] if the registration request includes DCCP
specific to the DCCP protocol [I-D.ietf-dccp-serv-codes]; the as a transport protocol, and MUST NOT include a requested DCCP
request MUST include a desired service code when the registration service code otherwise.
requests includes DCCP as a transport protocol, and MUST NOT
include one otherwise.
o Description: A short description of the service associated with o Description: A short description of the service associated with
the registration request is REQUIRED. It should avoid all but the the registration request is REQUIRED. It should avoid all but the
most well known acronyms. most well known acronyms.
o Reference: A reference document describing the protocol or o Reference: A description of (or a reference to a document
application using this port, including whether the protocol describing) the protocol or application using this port. The
supports either broadcast, multicast, or anycast communication. description must include whether the protocol uses either
For registration requests for Registered Ports, this documentation broadcast, multicast, or anycast communication.
MUST explain why a port number in the Dynamic Ports range is
unsuitable for the given application. For registration requests
for Well Known Ports, this documentation MUST explain why a port
number in the Registered Ports or Dynamic Ports ranges is
unsuitable.
"Early" registration requests can be made by IETF working groups For registrations requesting only a Service Name or a Service Name
without including such a reference document, although it is and Registered Port, a statement that the protocol is proprietary
RECOMMENDED that at least a reference to an Internet Draft and not publicly documented is also acceptable provided that the
describing the work in progress is provided. above information regarding use of broadcast, multicast, or
anycast is given.
For registration requests for a Registered Port, the registration
request MUST explain why a port number in the Dynamic Ports range
is unsuitable for the given application.
For registration requests for a Well Known Port, the registration
request MUST explain why a port number in the Registered Ports or
Dynamic Ports ranges is unsuitable, and a reference to a stable
protocol specification document MUST be provided. For requests
from IETF Working Groups, IANA MAY accept "Early" registration
requests referencing a sufficiently stable Internet Draft instead
of a published Standards-Track RFC [RFC4020].
When IANA receives a registration request containing the above When IANA receives a registration request containing the above
information, they SHALL initiate an "Expert Review" [RFC5226] in information requesting a port number, IANA SHALL initiate an "Expert
order to determine whether an assignment should be made. For Review" [RFC5226] in order to determine whether an assignment should
requests for service names that do not include port number be made. For requests that do not include a port number, IANA SHOULD
assignments, IANA MAY, at its discretion, skip the "Expert Review" assign the service name under a simple "First Come First Served"
procedure and assign the service name under a simple "First Come policy [RFC5226].
First Served" policy [RFC5226].
8.2. Port Number and Service Name De-Registration 8.2. Port Number and Service Name De-Registration
The original requesters of a granted port number assignment can The administrative contact of a granted port number assignment can
return the port number to IANA at any time if they no longer have a return the port number to IANA at any time if they no longer have a
need for it. The port number will be de-registered and will be need for it. The port number will be de-registered and will be
marked as Reserved. IANA should not re-assign port numbers that have marked as Reserved. IANA should not re-assign port numbers that have
been de-registered until all other available port numbers in the been de-registered until all other available port numbers in the
specific range have been assigned. specific range have been assigned.
Before proceeding with a port number de-registration, IANA needs to Before proceeding with a port number de-registration, IANA needs to
reasonably establish that the value is actually no longer in use. reasonably establish that the value is actually no longer in use.
Because there is much less danger of exhausting the service name Because there is much less danger of exhausting the service name
skipping to change at page 16, line 49 skipping to change at page 19, line 7
will appear in the registry as if it had been created through a will appear in the registry as if it had been created through a
service name registration request that did not include any port service name registration request that did not include any port
numbers. numbers.
On rare occasions, it may still be useful to de-register a service On rare occasions, it may still be useful to de-register a service
name. In such cases, IANA will mark the service name as Reserved. name. In such cases, IANA will mark the service name as Reserved.
IANA will involve their IESG-appointed expert in such cases. IANA will involve their IESG-appointed expert in such cases.
8.3. Port Number and Service Name Re-Use 8.3. Port Number and Service Name Re-Use
If the original requesters of a granted port number assignment no If the administrative contact of a granted port number assignment no
longer have a need for the registered number, but would like to re- longer have a need for the registered number, but would like to re-
use it for a different application, they can submit a request to IANA use it for a different application, they can submit a request to IANA
to do so. to do so.
Logically, port number re-use is to be thought of as a de- Logically, port number re-use is to be thought of as a de-
registration (Section 8.2) followed by an immediate re-registration registration (Section 8.2) followed by an immediate re-registration
(Section 8.1) of the same port number for a new application. (Section 8.1) of the same port number for a new application.
Consequently, the information that needs to be provided about the Consequently, the information that needs to be provided about the
proposed new use of the port number is identical to what would need proposed new use of the port number is identical to what would need
to be provided for a new port number allocation for the specific to be provided for a new port number allocation for the specific
skipping to change at page 18, line 25 skipping to change at page 20, line 30
assignments to be transferred between parties, even when they are assignments to be transferred between parties, even when they are
mutually consenting. mutually consenting.
The appropriate alternate procedure is a coordinated de-registration The appropriate alternate procedure is a coordinated de-registration
and registration: The new party requests the port number or service and registration: The new party requests the port number or service
name via a registration and the previous party releases its name via a registration and the previous party releases its
assignment via the de-registration procedure outlined above. assignment via the de-registration procedure outlined above.
With the help of their IESG-appointed Expert Reviewer, IANA SHALL With the help of their IESG-appointed Expert Reviewer, IANA SHALL
carefully determine if there is a valid technical, operational or carefully determine if there is a valid technical, operational or
managerial reason before performing the transfer. managerial reason to grant the requested new assignment.
8.6. Maintenance Issues 8.6. Maintenance Issues
The previous procedures help IANA manage the defining properties of In addition to the formal procedures described above, updates to the
the port name and service name registry. There are additional Description and Technical Contact information are coordinated by IANA
procedures which are administrative and help IANA maintain non- in an informal manner, and may be initiated by either the registrant
defining information in a registration. This includes changes to the or by IANA, e.g., by the latter requesting an update to current
Port Description and changes to Technical Contact information. (Note contact information. (Note that Registration Administrative Contact
that Registration Owner cannot be changed; see Section 8.5 above.) cannot be changed; see Section 8.5 above.)
These changes are coordinated by IANA in an informal manner, and may
be initiated by either the registrant or by IANA, e.g., the latter
when requesting an update to current contact information.
9. Security Considerations 9. Security Considerations
The IANA guidelines described in this document do not change the The IANA guidelines described in this document do not change the
security properties of UDP, TCP, SCTP, or DCCP. security properties of UDP, TCP, SCTP, or DCCP.
Assignment of a port number or service name does not in any way imply Assignment of a port number or service name does not in any way imply
an endorsement of an application or product, and the fact that an endorsement of an application or product, and the fact that
network traffic is flowing to or from a registered port number does network traffic is flowing to or from a registered port number does
not mean that it is "good" traffic, or even that it is used by the not mean that it is "good" traffic, or even that it is used by the
skipping to change at page 19, line 22 skipping to change at page 21, line 25
This document obsoletes Sections 8 and 9.1 of the March 2000 IANA This document obsoletes Sections 8 and 9.1 of the March 2000 IANA
Allocation Guidelines [RFC2780]. Allocation Guidelines [RFC2780].
Upon approval of this document, IANA is requested to contact the Upon approval of this document, IANA is requested to contact the
maintainer of the [SRVREG] registry, in order to merge the contents maintainer of the [SRVREG] registry, in order to merge the contents
of that private registry into the official IANA registry. It is of that private registry into the official IANA registry. It is
expected that the contents of [SRVREG] will at that time be replaced expected that the contents of [SRVREG] will at that time be replaced
with pointers to the IANA registry and to this RFC. with pointers to the IANA registry and to this RFC.
Similarly, IANA is instructed to create a new service name entry in IANA is instructed to create a new service name entry in the port
the port number registry [PORTREG] for any entry in the "Protocol and number registry [PORTREG] for any entry in the "Protocol and Service
Service Names" registry [PROTSERVREG] that does not already have one Names" registry [PROTSERVREG] that does not already have one
assigned. After that, IANA should investigate if the "Protocol and assigned.
Service Names" registry [PROTSERVREG] can be retired.
10.1. Service Name Consistency 10.1. Service Name Consistency
Section 8.1 defines which character strings are well-formed service Section 8.1 defines which character strings are well-formed service
names, which until now had not been clearly defined. The definition names, which until now had not been clearly defined. The definition
in Section 8.1 was chosen to allow maximum compatibility of service in Section 8.1 was chosen to allow maximum compatibility of service
names with current and future service discovery mechanisms. names with current and future service discovery mechanisms.
As of August 5, 2009 approximately 98% of the so-called "Short Names" As of August 5, 2009 approximately 98% of the so-called "Short Names"
from existing port number registrations [PORTREG] meet the rules for from existing port number registrations [PORTREG] meet the rules for
legal service names stated in Section 8.1, and hence will be used legal service names stated in Section 8.1, and hence will be used
unmodified. unmodified.
The remaining approximately 2% of the exiting "Short Names" are not The remaining approximately 2% of the exiting "Short Names" are not
suitable to be used directly as well-formed service names because suitable to be used directly as well-formed service names because
they contain illegal characters such as asterisks, dots, plusses, they contain illegal characters such as asterisks, dots, plusses,
slashes, or underscores. All existing "Short Names" conform to the slashes, or underscores. All existing "Short Names" conform to the
length requirement of 15 characters or less. For these unsuitable length requirement of 15 characters or fewer. For these unsuitable
"Short Names", listed in the table below, the service name will be "Short Names", listed in the table below, the service name will be
the Short Name with any illegal characters replaced by hyphens. IANA the Short Name with any illegal characters replaced by hyphens. IANA
SHALL add an alias to the registry that assigns a well-formed service SHALL add an entry to the registry giving the new well-formed primary
name for the existing service but otherwise duplicates the original service name for the existing service, that otherwise duplicates the
assignment information. In the description field of the new alias, original assignment information. In the description field of this
IANA SHALL record that it assigns a well-formed service name for the new entry giving the primary service name, IANA SHALL record that it
previous service and point to the original assignment. In the assigns a well-formed service name for the previous service and
description field of the original assignment, IANA SHALL add a note reference the original assignment. In the description field of the
that the service name is historic, is not usable with many common original assignment, IANA SHALL add a note that this entry is an
service discovery mechanisms, and provide a reference to the new alias to the new well-formed service name, and that the old service
alias, which can be used in this way. name is historic, not usable for use with many common service
discovery mechanisms.
Names containing illegal characters to be replaced by hyphens: Names containing illegal characters to be replaced by hyphens:
+----------------+-----------------+-----------------+ +----------------+-----------------+-----------------+
| 914c/g | acmaint_dbd | acmaint_transd | | 914c/g | acmaint_dbd | acmaint_transd |
| atex_elmd | avanti_cdp | badm_priv | | atex_elmd | avanti_cdp | badm_priv |
| badm_pub | bdir_priv | bdir_pub | | badm_pub | bdir_priv | bdir_pub |
| bmc_ctd_ldap | bmc_patroldb | boks_clntd | | bmc_ctd_ldap | bmc_patroldb | boks_clntd |
| boks_servc | boks_servm | broker_service | | boks_servc | boks_servm | broker_service |
| bues_service | canit_store | cedros_fds | | bues_service | canit_store | cedros_fds |
skipping to change at page 20, line 46 skipping to change at page 23, line 42
| pra_elmd | printer_agent | redstorm_diag | | pra_elmd | printer_agent | redstorm_diag |
| redstorm_find | redstorm_info | redstorm_join | | redstorm_find | redstorm_info | redstorm_join |
| resource_mgr | rmonitor_secure | rsvp_tunnel | | resource_mgr | rmonitor_secure | rsvp_tunnel |
| sai_sentlm | sge_execd | sge_qmaster | | sai_sentlm | sge_execd | sge_qmaster |
| shiva_confsrvr | sql*net | srvc_registry | | shiva_confsrvr | sql*net | srvc_registry |
| stm_pproc | subntbcst_tftp | udt_os | | stm_pproc | subntbcst_tftp | udt_os |
| universe_suite | veritas_pbx | vision_elmd | | universe_suite | veritas_pbx | vision_elmd |
| vision_server | wrs_registry | z39.50 | | vision_server | wrs_registry | z39.50 |
+----------------+-----------------+-----------------+ +----------------+-----------------+-----------------+
In the case of "whois++", the service name will be "whoisplusplus". Following the example set by the "application/whoispp-query" MIME
Content-Type [RFC2957], the service name for "whois++" will be
"whoispp".
10.2. Port Numbers for SCTP and DCCP Experimentation 10.2. Port Numbers for SCTP and DCCP Experimentation
Two Well Known UDP and TCP ports, 1021 and 1022, have been reserved Two Well Known UDP and TCP ports, 1021 and 1022, have been reserved
for experimental use [RFC4727]. This document registers the same for experimental use [RFC4727]. This document registers the same
port numbers for SCTP and DCCP, and also instructs IANA to port numbers for SCTP and DCCP, and also instructs IANA to
automatically register these two port numbers for any new transport automatically register these two port numbers for any new transport
protocol that will in the future share the port number namespace. protocol that will in the future share the port number namespace.
Note that these port numbers are meant for temporary experimentation Note that these port numbers are meant for temporary experimentation
and development in controlled environments. Before using these port and development in controlled environments. Before using these port
numbers, carefully consider the advice in Section 6.1 in this numbers, carefully consider the advice in Section 6.1 in this
document, as well as in Sections 1 and 1.1 of "Assigning Experimental document, as well as in Sections 1 and 1.1 of "Assigning Experimental
and Testing Numbers Considered Useful" [RFC3692]. Most importantly, and Testing Numbers Considered Useful" [RFC3692]. Most importantly,
application developers must request a permanent port number application developers must request a permanent port number
assignment from IANA as described in Section 8.1 before any kind of assignment from IANA as described in Section 8.1 before any kind of
non-experimental deployment. non-experimental deployment.
+--------------------------------+----------------------------+ +-------------------------------------+----------------------------+
| Registration Technical Contact | IESG <iesg@ietf.org> | | Registration Administrative Contact | IETF <iesg@ietf.org> |
| Registration Owner | IETF <iesg@ietf.org> | | Registration Technical Contact | IESG <iesg@ietf.org> |
| Transport Protocol | SCTP, DCCP | | Service Name | exp1 |
| Port Number | 1021 | | Port Number | 1021 |
| Port Name | RFC3692-style Experiment 1 | | Transport Protocol | SCTP, DCCP |
| Service Name | exp1 | | Description | RFC3692-style Experiment 1 |
| Reference | [RFCyyyy] | | Reference | [RFCyyyy] |
+--------------------------------+----------------------------+ +-------------------------------------+----------------------------+
+--------------------------------+----------------------------+ +-------------------------------------+----------------------------+
| Registration Technical Contact | IESG <iesg@ietf.org> | | Registration Administrative Contact | IETF <iesg@ietf.org> |
| Registration Owner | IETF <iesg@ietf.org> | | Registration Technical Contact | IESG <iesg@ietf.org> |
| Transport Protocol | SCTP, DCCP | | Service Name | exp2 |
| Port Number | 1022 | | Port Number | 1022 |
| Port Name | RFC3692-style Experiment 2 | | Transport Protocol | SCTP, DCCP |
| Service Name | exp2 | | Description | RFC3692-style Experiment 2 |
| Reference | [RFCyyyy] | | Reference | [RFCyyyy] |
+--------------------------------+----------------------------+ +-------------------------------------+----------------------------+
[RFC Editor Note: Please change "yyyy" to the RFC number allocated to [RFC Editor Note: Please change "yyyy" to the RFC number allocated to
this document before publication.] this document before publication.]
10.3. Updates to DCCP Registries 10.3. Updates to DCCP Registries
This document updates the IANA allocation procedures for the DCCP This document updates the IANA allocation procedures for the DCCP
Port Number and DCCP Service Codes Registries [RFC4340]. Port Number and DCCP Service Codes Registries [RFC4340].
10.3.1. DCCP Service Code Registry 10.3.1. DCCP Service Code Registry
skipping to change at page 22, line 43 skipping to change at page 25, line 39
already allocated Port Number requires Expert Review. These already allocated Port Number requires Expert Review. These
requests will normally be accepted when they originate from the requests will normally be accepted when they originate from the
contact associated with the port registration. In other cases, contact associated with the port registration. In other cases,
these applications will be expected to use an unallocated port, these applications will be expected to use an unallocated port,
when this is available. when this is available.
The DCCP specification [RFC4340] notes that a short port name MUST be The DCCP specification [RFC4340] notes that a short port name MUST be
associated with each DCCP server port that has been registered. This associated with each DCCP server port that has been registered. This
document requires that this name MUST be unique. document requires that this name MUST be unique.
11. Acknowledgments 11. Contributors
Stuart Cheshire (cheshire@apple.com), Alfred Hoenes (ah@tr-sys.de)
and Allison Mankin (mankin@psg.com) have contributed text and ideas
to this document.
12. Acknowledgments
The text in Section 10.3 is based on a suggestion by Tom Phelan. The text in Section 10.3 is based on a suggestion by Tom Phelan.
Lars Eggert is partly funded by the Trilogy Project [TRILOGY], a Lars Eggert is partly funded by the Trilogy Project [TRILOGY], a
research project supported by the European Commission under its research project supported by the European Commission under its
Seventh Framework Program. Seventh Framework Program.
12. References 13. References
12.1. Normative References 13.1. Normative References
[ANSI.X3-4.1986] [ANSI.X3-4.1986]
American National Standards Institute, "Coded Character American National Standards Institute, "Coded Character
Set - 7-bit American Standard Code for Information Set - 7-bit American Standard Code for Information
Interchange", ANSI X3.4, 1986. Interchange", ANSI X3.4, 1986.
[RFC0768] Postel, J., "User Datagram Protocol", STD 6, RFC 768, [RFC0768] Postel, J., "User Datagram Protocol", STD 6, RFC 768,
August 1980. August 1980.
[RFC0793] Postel, J., "Transmission Control Protocol", STD 7, [RFC0793] Postel, J., "Transmission Control Protocol", STD 7,
skipping to change at page 23, line 45 skipping to change at page 26, line 46
[RFC4340] Kohler, E., Handley, M., and S. Floyd, "Datagram [RFC4340] Kohler, E., Handley, M., and S. Floyd, "Datagram
Congestion Control Protocol (DCCP)", RFC 4340, March 2006. Congestion Control Protocol (DCCP)", RFC 4340, March 2006.
[RFC4727] Fenner, B., "Experimental Values In IPv4, IPv6, ICMPv4, [RFC4727] Fenner, B., "Experimental Values In IPv4, IPv6, ICMPv4,
ICMPv6, UDP, and TCP Headers", RFC 4727, November 2006. ICMPv6, UDP, and TCP Headers", RFC 4727, November 2006.
[RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an [RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an
IANA Considerations Section in RFCs", BCP 26, RFC 5226, IANA Considerations Section in RFCs", BCP 26, RFC 5226,
May 2008. May 2008.
12.2. Informative References [RFC5234] Crocker, D. and P. Overell, "Augmented BNF for Syntax
Specifications: ABNF", STD 68, RFC 5234, January 2008.
13.2. Informative References
[I-D.cheshire-dnsext-dns-sd] [I-D.cheshire-dnsext-dns-sd]
Cheshire, S. and M. Krochmal, "DNS-Based Service Cheshire, S. and M. Krochmal, "DNS-Based Service
Discovery", draft-cheshire-dnsext-dns-sd-05 (work in Discovery", draft-cheshire-dnsext-dns-sd-05 (work in
progress), September 2008. progress), September 2008.
[I-D.cheshire-nat-pmp] [I-D.cheshire-nat-pmp]
Cheshire, S., "NAT Port Mapping Protocol (NAT-PMP)", Cheshire, S., "NAT Port Mapping Protocol (NAT-PMP)",
draft-cheshire-nat-pmp-03 (work in progress), April 2008. draft-cheshire-nat-pmp-03 (work in progress), April 2008.
[I-D.ietf-dccp-serv-codes] [I-D.gudmundsson-dnsext-srv-clarify]
Fairhurst, G., "The DCCP Service Code", Gudmundsson, O. and A. Hoenes, "Clarification of DNS SRV
draft-ietf-dccp-serv-codes-11 (work in progress), Owner Names", draft-gudmundsson-dnsext-srv-clarify-00
May 2009. (work in progress), December 2009.
[I-D.touch-tcp-portnames] [IGD] UPnP Forum, "Internet Gateway Device (IGD) V 1.0",
Touch, J., "A TCP Option for Port Names", November 2001.
draft-touch-tcp-portnames-00 (work in progress),
April 2006.
[PORTREG] Internet Assigned Numbers Authority (IANA), "Port Numbers [PORTREG] Internet Assigned Numbers Authority (IANA), "Port Numbers
Registry", http://www.iana.org/assignments/port-numbers. Registry", http://www.iana.org/assignments/port-numbers.
[PROTSERVREG] [PROTSERVREG]
Internet Assigned Numbers Authority (IANA), "Protocol and Internet Assigned Numbers Authority (IANA), "Protocol and
Service Names Registry", Service Names Registry",
http://www.iana.org/assignments/service-names. http://www.iana.org/assignments/service-names.
[RFC0952] Harrenstien, K., Stahl, M., and E. Feinler, "DoD Internet
host table specification", RFC 952, October 1985.
[RFC0959] Postel, J. and J. Reynolds, "File Transfer Protocol", [RFC0959] Postel, J. and J. Reynolds, "File Transfer Protocol",
STD 9, RFC 959, October 1985. STD 9, RFC 959, October 1985.
[RFC1078] Lottor, M., "TCP port service Multiplexer (TCPMUX)", [RFC1078] Lottor, M., "TCP port service Multiplexer (TCPMUX)",
RFC 1078, November 1988. RFC 1078, November 1988.
[RFC1700] Reynolds, J. and J. Postel, "Assigned Numbers", RFC 1700, [RFC1700] Reynolds, J. and J. Postel, "Assigned Numbers", RFC 1700,
October 1994. October 1994.
[RFC2782] Gulbrandsen, A., Vixie, P., and L. Esibov, "A DNS RR for [RFC2782] Gulbrandsen, A., Vixie, P., and L. Esibov, "A DNS RR for
specifying the location of services (DNS SRV)", RFC 2782, specifying the location of services (DNS SRV)", RFC 2782,
February 2000. February 2000.
[RFC2957] Daigle, L. and P. Faltstrom, "The application/
whoispp-query Content-Type", RFC 2957, October 2000.
[RFC3232] Reynolds, J., "Assigned Numbers: RFC 1700 is Replaced by [RFC3232] Reynolds, J., "Assigned Numbers: RFC 1700 is Replaced by
an On-line Database", RFC 3232, January 2002. an On-line Database", RFC 3232, January 2002.
[RFC3692] Narten, T., "Assigning Experimental and Testing Numbers [RFC3692] Narten, T., "Assigning Experimental and Testing Numbers
Considered Useful", BCP 82, RFC 3692, January 2004. Considered Useful", BCP 82, RFC 3692, January 2004.
[RFC4342] Floyd, S., Kohler, E., and J. Padhye, "Profile for [RFC4342] Floyd, S., Kohler, E., and J. Padhye, "Profile for
Datagram Congestion Control Protocol (DCCP) Congestion Datagram Congestion Control Protocol (DCCP) Congestion
Control ID 3: TCP-Friendly Rate Control (TFRC)", RFC 4342, Control ID 3: TCP-Friendly Rate Control (TFRC)", RFC 4342,
March 2006. March 2006.
[RFC4960] Stewart, R., "Stream Control Transmission Protocol", [RFC4960] Stewart, R., "Stream Control Transmission Protocol",
RFC 4960, September 2007. RFC 4960, September 2007.
[RFC5237] Arkko, J. and S. Bradner, "IANA Allocation Guidelines for [RFC5237] Arkko, J. and S. Bradner, "IANA Allocation Guidelines for
the Protocol Field", BCP 37, RFC 5237, February 2008. the Protocol Field", BCP 37, RFC 5237, February 2008.
[RFC5595] Fairhurst, G., "The Datagram Congestion Control Protocol
(DCCP) Service Codes", RFC 5595, September 2009.
[SRVREG] "DNS SRV Service Types Registry", [SRVREG] "DNS SRV Service Types Registry",
http://www.dns-sd.org/ServiceTypes.html. http://www.dns-sd.org/ServiceTypes.html.
[SYSFORM] Internet Assigned Numbers Authority (IANA), "Application [SYSFORM] Internet Assigned Numbers Authority (IANA), "Application
for System (Well Known) Port Number", for System (Well Known) Port Number",
http://www.iana.org/cgi-bin/sys-port-number.pl. http://www.iana.org/cgi-bin/sys-port-number.pl.
[TRILOGY] "Trilogy Project", http://www.trilogy-project.org/. [TRILOGY] "Trilogy Project", http://www.trilogy-project.org/.
[UPnP] UPnP Forum, "Internet Gateway Device (IGD) V 1.0",
November 2001.
[USRFORM] Internet Assigned Numbers Authority (IANA), "Application [USRFORM] Internet Assigned Numbers Authority (IANA), "Application
for User (Registered) Port Number", for User (Registered) Port Number",
http://www.iana.org/cgi-bin/usr-port-number.pl. http://www.iana.org/cgi-bin/usr-port-number.pl.
Authors' Addresses Authors' Addresses
Michelle Cotton Michelle Cotton
Internet Corporation for Assigned Names and Numbers Internet Corporation for Assigned Names and Numbers
4676 Admiralty Way, Suite 330 4676 Admiralty Way, Suite 330
Marina del Rey, CA 90292 Marina del Rey, CA 90292
skipping to change at page 25, line 38 skipping to change at page 29, line 4
Michelle Cotton Michelle Cotton
Internet Corporation for Assigned Names and Numbers Internet Corporation for Assigned Names and Numbers
4676 Admiralty Way, Suite 330 4676 Admiralty Way, Suite 330
Marina del Rey, CA 90292 Marina del Rey, CA 90292
USA USA
Phone: +1 310 823 9358 Phone: +1 310 823 9358
Email: michelle.cotton@icann.org Email: michelle.cotton@icann.org
URI: http://www.iana.org/ URI: http://www.iana.org/
Lars Eggert Lars Eggert
Nokia Research Center Nokia Research Center
P.O. Box 407 P.O. Box 407
Nokia Group 00045 Nokia Group 00045
Finland Finland
Phone: +358 50 48 24461 Phone: +358 50 48 24461
Email: lars.eggert@nokia.com Email: lars.eggert@nokia.com
URI: http://research.nokia.com/people/lars_eggert/ URI: http://research.nokia.com/people/lars_eggert/
Allison Mankin
Johns Hopkins University
Phone: +1 301 728 7199
Email: mankin@psg.com
URI: http://www.psg.com/~mankin/
Joe Touch Joe Touch
USC/ISI USC/ISI
4676 Admiralty Way 4676 Admiralty Way
Marina del Rey, CA 90292 Marina del Rey, CA 90292
USA USA
Phone: +1 310 448 9151 Phone: +1 310 448 9151
Email: touch@isi.edu Email: touch@isi.edu
URI: http://www.isi.edu/touch URI: http://www.isi.edu/touch
 End of changes. 78 change blocks. 
325 lines changed or deleted 420 lines changed or added

This html diff was produced by rfcdiff 1.37b. The latest version is available from http://tools.ietf.org/tools/rfcdiff/