draft-ietf-mmusic-sdp-comedia-07.txt   draft-ietf-mmusic-sdp-comedia-08.txt 
MMUSIC Working Group D. Yon MMUSIC Working Group D. Yon
Internet-Draft Dialout.Net, Inc Internet-Draft Dialout.Net, Inc
Expires: December 10, 2004 G. Camarillo Expires: January 14, 2005 G. Camarillo
Ericsson Ericsson
June 11, 2004 July 16, 2004
Connection-Oriented Media Transport in the Session Description Connection-Oriented Media Transport in the Session Description
Protocol (SDP) Protocol (SDP)
draft-ietf-mmusic-sdp-comedia-07.txt draft-ietf-mmusic-sdp-comedia-08.txt
Status of this Memo Status of this Memo
By submitting this Internet-Draft, I certify that any applicable By submitting this Internet-Draft, I certify that any applicable
patent or other IPR claims of which I am aware have been disclosed, patent or other IPR claims of which I am aware have been disclosed,
and any of which I become aware will be disclosed, in accordance with and any of which I become aware will be disclosed, in accordance with
RFC 3668. RFC 3668.
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 other Task Force (IETF), its areas, and its working groups. Note that other
skipping to change at page 1, line 35 skipping to change at page 1, line 35
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 http:// The list of current Internet-Drafts can be accessed at http://
www.ietf.org/ietf/1id-abstracts.txt. 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 December 10, 2004. This Internet-Draft will expire on January 14, 2005.
Copyright Notice Copyright Notice
Copyright (C) The Internet Society (2004). All Rights Reserved. Copyright (C) The Internet Society (2004). All Rights Reserved.
Abstract Abstract
This document describes how to express media transport over This document describes how to express media transport over
connection-oriented protocols using the Session Description Protocol connection-oriented protocols using the Session Description Protocol
(SDP). It defines the SDP TCP protocol identifier, the SDP setup (SDP). It defines the SDP TCP protocol identifier, the SDP setup
skipping to change at page 2, line 14 skipping to change at page 2, line 14
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Protocol Identifier . . . . . . . . . . . . . . . . . . . . . 3 3. Protocol Identifier . . . . . . . . . . . . . . . . . . . . . 3
4. Setup Attribute . . . . . . . . . . . . . . . . . . . . . . . 4 4. Setup Attribute . . . . . . . . . . . . . . . . . . . . . . . 4
4.1 The Setup Attribute in the Offer/answer Model . . . . . . 4 4.1 The Setup Attribute in the Offer/answer Model . . . . . . 4
5. The Connid Attribute . . . . . . . . . . . . . . . . . . . . . 5 5. The Connid Attribute . . . . . . . . . . . . . . . . . . . . . 5
5.1 Offerer Behaviour . . . . . . . . . . . . . . . . . . . . 6 5.1 Offerer Behaviour . . . . . . . . . . . . . . . . . . . . 6
5.2 Answerer Behaviour . . . . . . . . . . . . . . . . . . . . 6 5.2 Answerer Behaviour . . . . . . . . . . . . . . . . . . . . 7
6. Connection Management . . . . . . . . . . . . . . . . . . . . 7 6. Connection Management . . . . . . . . . . . . . . . . . . . . 7
7. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 7. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
7.1 Passive/Active . . . . . . . . . . . . . . . . . . . . . . 8 7.1 Passive/Active . . . . . . . . . . . . . . . . . . . . . . 8
7.2 Passive/Active with Connection Reestablishment . . . . . . 8 7.2 Passive/Active with Connection Reestablishment . . . . . . 9
7.3 Actpass/Passive . . . . . . . . . . . . . . . . . . . . . 9 7.3 Actpass/Passive . . . . . . . . . . . . . . . . . . . . . 9
8. Security Considerations . . . . . . . . . . . . . . . . . . . 9 8. Security Considerations . . . . . . . . . . . . . . . . . . . 10
9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 10 9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 10
10. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 10 10. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 10
11. References . . . . . . . . . . . . . . . . . . . . . . . . . 10 11. References . . . . . . . . . . . . . . . . . . . . . . . . . 10
11.1 Normative References . . . . . . . . . . . . . . . . . . . . 10 11.1 Normative References . . . . . . . . . . . . . . . . . . . . 10
11.2 Informational References . . . . . . . . . . . . . . . . . . 10 11.2 Informative References . . . . . . . . . . . . . . . . . . . 11
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . 11 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . 11
Intellectual Property and Copyright Statements . . . . . . . . 12 Intellectual Property and Copyright Statements . . . . . . . . 13
1. Introduction 1. Introduction
The Session Description Protocol [3] provides a general-purpose The Session Description Protocol [3] provides a general-purpose
format for describing multimedia sessions in announcements or format for describing multimedia sessions in announcements or
invitations. SDP uses an entirely textual data format (the US-ASCII invitations. SDP uses an entirely textual data format (the US-ASCII
subset of UTF-8 [5]) to maximize portability among transports. SDP subset of UTF-8 [10]) to maximize portability among transports. SDP
does not define a protocol, but only the syntax to describe a does not define a protocol, but only the syntax to describe a
multimedia session with sufficient information to participate in that multimedia session with sufficient information to participate in that
session. Session descriptions may be sent using arbitrary existing session. Session descriptions may be sent using arbitrary existing
application protocols for transport (e.g., SAP [9], SIP [10], RTSP application protocols for transport (e.g., SAP [8], SIP [9], RTSP
[6], email, HTTP [8], etc.). [5], email, HTTP [7], etc.).
SDP [3] defines two protocol identifiers: RTP/AVP and UDP, both of SDP [3] defines two protocol identifiers: RTP/AVP and UDP, both of
which represent unreliable connectionless protocols. While these which represent unreliable connectionless protocols. While these
transports are appropriate choices for multimedia streams, there are transports are appropriate choices for multimedia streams, there are
applications for which connection-oriented transports, such as TCP, applications for which connection-oriented transports, such as TCP,
are more appropriate. We define a new protocol identifier, TCP, to are more appropriate. This document defines a new protocol
describe TCP connetions in SDP. identifier, TCP, to describe TCP connetions in SDP.
Connection-oriented protocols introduce two new factor when Connection-oriented protocols introduce two new factor when
describing a session: how and when should end points perform the describing a session: how and when should end points perform the
connection setup procedure. We define two new attributes to describe connection setup procedure. This document defines two new attributes
connection setups: setup and connid. to describe connection setups: setup and connid.
2. Terminology 2. Terminology
In this document, the key words "MUST", "MUST NOT", "REQUIRED", In this document, the key words "MUST", "MUST NOT", "REQUIRED",
"SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT
RECOMMENDED", "MAY", and "OPTIONAL" are to be interpreted as RECOMMENDED", "MAY", and "OPTIONAL" are to be interpreted as
described in BCP 14, RFC 2119 [2] and indicate requirement levels for described in BCP 14, RFC 2119 [2] and indicate requirement levels for
compliant implementations. compliant implementations.
3. Protocol Identifier 3. Protocol Identifier
The following is the ABNF for an m= line, as specified by RFC 2327 The following is the ABNF for an m= line, as specified by RFC 2327
[3]. [3].
media-field = "m=" media space port ["/" integer] media-field = "m=" media space port ["/" integer]
space proto 1*(space fmt) CRLF space proto 1*(space fmt) CRLF
We define a new values for the proto field: TCP. This document defines a new value for the proto field: TCP.
The TCP protocol identifier is similar to the UDP protocol identifier The TCP protocol identifier is similar to the UDP protocol identifier
in that it only describes the transport protocol, and not the in that it only describes the transport protocol, and not the
upper-layer protocol. An m= line that specifies "TCP" MUST further upper-layer protocol. An m= line that specifies "TCP" MUST further
qualify the application-layer protocol using an fmt identifier. Media qualify the application-layer protocol using an fmt identifier. Media
lines with the TCP protocol identifier are carried using TCP [1]. lines with the TCP protocol identifier are carried using TCP [1].
It is RECOMMENDED that documents defining new SDP protocol It is RECOMMENDED that documents defining new SDP protocol
identifiers that involve extra protocol layers between TCP and the identifiers that involve extra protocol layers between TCP and the
media itself (e.g., TLS [7] over TCP) start with the string "TCP/" media itself (e.g., TLS [6] over TCP) start with the string "TCP/"
(e.g., TCP/TLS). (e.g., TCP/TLS).
The following sections define the setup and the connid attributes. The following sections define the setup and the connid attributes.
While they are applicable to m= lines that use the TCP protocol While both attributes are applicable to m= lines that use the TCP
identifier, they are not limited to them. These attributes SHOULD be protocol identifier, they are not limited to them. These attributes
used in any m= line which uses a connection-oriented transport MAY be used in any m= line which uses a connection-oriented transport
protocol, even if the protocol identifier of the m= line is not TCP. protocol, even if the protocol identifier of the m= line is not TCP.
4. Setup Attribute 4. Setup Attribute
The setup attribute indicates which of the end points should initiate The setup attribute indicates which of the end points should initiate
the connection establishment (e.g., send the initial TCP SYN). The the connection establishment (e.g., send the initial TCP SYN). The
setup attribute is charset-independent and can be a session-level or setup attribute is charset-independent and can be a session-level or
a media-level attribute. The following is the ABNF of the setup a media-level attribute. The following is the ABNF of the setup
attribute: attribute:
setup-attr = "a=setup:" role setup-attr = "a=setup:" role
role = "active" / "passive" / "actpass" role = "active" / "passive" / "actpass"
/ "holdconn"
Active: The endpoint will initiate an outgoing connection. Active: The endpoint will initiate an outgoing connection.
Passive: The endpoint will accept an incoming connection. Passive: The endpoint will accept an incoming connection.
ActPass: The endpoint is willing to accept an incoming connection ActPass: The endpoint is willing to accept an incoming connection
or to initiate an outgoing connection. or to initiate an outgoing connection.
Holdconn: The endpoint does not want the connection to be
established for the time being.
4.1 The Setup Attribute in the Offer/answer Model 4.1 The Setup Attribute in the Offer/answer Model
The offer/answer model, defined in RFC 3264 [4], provides endpoints The offer/answer model, defined in RFC 3264 [4], provides endpoints
with a means to obtain shared view of a session. Some session with a means to obtain shared view of a session. Some session
parameters are negotiated (e.g., codecs to use), while others are parameters are negotiated (e.g., codecs to use), while others are
simply communicated from one endpoint to the other (e.g., IP simply communicated from one endpoint to the other (e.g., IP
addresses). The value of the setup attribute falls into the first addresses). The value of the setup attribute falls into the first
category. That is, both endpoints negotiate its value using the category. That is, both endpoints negotiate its value using the
offer/answer model. offer/answer model.
The negotiation of the value of the setup attribute takes places as The negotiation of the value of the setup attribute takes places as
follows. The offerer states which role or roles is willing to perform follows. The offerer states which role or roles it is willing to
and the answerer, taking the offerer's willingness into perform and the answerer, taking the offerer's willingness into
consideration, chooses which roles both endpoints will actually consideration, chooses which roles both endpoints will actually
perform during connection establishment. The following are the values perform during connection establishment. The following are the values
that the setup attribute can take in an offer/answer exchange: that the setup attribute can take in an offer/answer exchange:
Offer Answer Offer Answer
_______________ ________________
active passive active passive / holdconn
passive active passive active / holdconn
actpass active / passive actpass active / passive / holdconn
holdconn holdconn
The value active indicates that the endpoint SHOULD initiate a The active endpoint SHOULD initiate a connection to the port number
connection to the port number on the m= line of the other endpoint. on the m= line of the other endpoint. The port number on its own m=
The port number on its own m= line is irrelevant, and the opposite line is irrelevant, and the opposite endpoint MUST NOT attempt to
endpoint MUST NOT attempt to initiate a connection to the port number initiate a connection to the port number specified there.
specified there. Nevertheless, since the m= line must contain a valid Nevertheless, since the m= line must contain a valid port number, the
port number, the endpoint specifying using the value active SHOULD endpoint specifying using the value active SHOULD specify a port
specify a port number of 9 (the discard port) on its m= line. The number of 9 (the discard port) on its m= line. The endpoint MUST NOT
endpoint MUST NOT specify a port number of zero, except to denote an specify a port number of zero, except to denote an m= line that has
m= line that has been or is being refused. been or is being refused.
The value passive indicates that the endpoint SHOULD be ready to The passive endpoint SHOULD be ready to accept a connection on the
accept a connection on the port number specified in the m= line. port number specified in the m= line.
The value actpass indicates that the offerer can either initiate a A value of actpass indicates that the offerer can either initiate a
connection to the port number on the m= line in the answer or accept connection to the port number on the m= line in the answer or accept
a connection on the port number specified in the m= line in the a connection on the port number specified in the m= line in the
offer. That is, the offerer has no preference as to whether it offer. That is, the offerer has no preference as to whether it
accepts or initiates the connection and, so, is letting the answerer accepts or initiates the connection and, so, is letting the answerer
choose. choose.
A value of holdconn indicates that the connection should not be
established for the time being.
The default value of the setup attribute in an offer/answer exchange The default value of the setup attribute in an offer/answer exchange
is active in the offer and passive in the answer. is active in the offer and passive in the answer.
5. The Connid Attribute 5. The Connid Attribute
The preceding description of the setup attribute has been in the The preceding description of the setup attribute has been in the
context of using SDP to initiate a session. Still, SDP may be context of using SDP to initiate a session. Still, SDP may be
exchanged between endpoints at various stages of a session to exchanged between endpoints at various stages of a session to
accomplish tasks such as terminating a session, redirecting media to accomplish tasks such as terminating a session, redirecting media to
a new endpoint, or renegotiating the media parameters for a session. a new endpoint, or renegotiating the media parameters for a session.
skipping to change at page 6, line 35 skipping to change at page 6, line 44
m= line, the offerer MUST use the same connid value for the m= line. m= line, the offerer MUST use the same connid value for the m= line.
If, on the other hand, the offerer wants to establish a new If, on the other hand, the offerer wants to establish a new
transport-layer connection for the m= line, it MUST use a new connid transport-layer connection for the m= line, it MUST use a new connid
value. This new connid value MUST be different from the current value. This new connid value MUST be different from the current
connid value in use and SHOULD be different than any connid value connid value in use and SHOULD be different than any connid value
used previously in the same m= line. used previously in the same m= line.
The connid value in an offer is only compared with the connid The connid value in an offer is only compared with the connid
value currently in use. So, having a connid value different than value currently in use. So, having a connid value different than
the one in use is enough to trigger the establishment of a new the one in use is enough to trigger the establishment of a new
connection. Still, we recommend to use a value different than all connection. Still, it is recommended to use a value different than
the previous ones used in the m= line to make debugging easier. all the previous ones used in the m= line to make debugging
easier.
Note that, according to the rules in this section, an offer that Note that, according to the rules in this section, an offer that
changes the transport address (IP address plus port number) of an changes the transport address (IP address plus port number) of an
m= line will have a new connid value for this m=line. m= line will have a new connid value for this m=line.
5.2 Answerer Behaviour 5.2 Answerer Behaviour
The connid value for an m= line is negotiated using the offer/answer The connid value for an m= line is negotiated using the offer/answer
model. The resulting connid value after an offer/answer exchange is model. The resulting connid value after an offer/answer exchange is
the connid value in the answer. the connid value in the answer.
skipping to change at page 7, line 14 skipping to change at page 7, line 26
the offer contains the connid value in use but the answerer wishes to the offer contains the connid value in use but the answerer wishes to
establish a new transport-layer connection, the answerer MUST use a establish a new transport-layer connection, the answerer MUST use a
new connid value in the answer. new connid value in the answer.
If the connid value for an m= line resulting from an offer/answer If the connid value for an m= line resulting from an offer/answer
exchange is different than the connid in use so far, the endpoints exchange is different than the connid in use so far, the endpoints
SHOULD establish a new transport-layer connection as indicated by the SHOULD establish a new transport-layer connection as indicated by the
setup attribute. If a previous connection is still up, the endpoint setup attribute. If a previous connection is still up, the endpoint
responsible for establishing the new connection performing the active responsible for establishing the new connection performing the active
role SHOULD close it as soon as the offer/answer exchange is role SHOULD close it as soon as the offer/answer exchange is
completed. completed. It is up to the application to ensure proper data
synchornization between the two connections.
If the connid value for an m= line resulting from an offer/answer If the connid value for an m= line resulting from an offer/answer
exchange is the same as the connid in use so far, the endpoints exchange is the same as the connid in use so far, the endpoints
SHOULD continue using the existing connection. SHOULD continue using the existing connection.
In the past, it was proposed to use the presence of a media-level In the past, it was proposed to use the presence of a media-level
SDP attribute as a flag to indicate that a new connection needed SDP attribute as a flag to indicate that a new connection needed
to be established. We chose not to follow the flag approach to be established. It was decided not to follow the flag approach
because an offerer whose intent was to signal "no changes" in a because an offerer whose intent was to signal "no changes" in a
session would need to issue a different offer than the previous session would need to issue a different offer than the previous
one (i.e., it would need to remove the flag from the m= line). By one (i.e., it would need to remove the flag from the m= line). By
using the connid attribute instead, an offerer signals "no using the connid attribute instead, an offerer signals "no
changes" in a session by issuing an identical offer to the one in changes" in a session by issuing an identical offer to the one in
use. use.
6. Connection Management 6. Connection Management
An endpoint that according to an offer/answer exchange is supposed to An endpoint that according to an offer/answer exchange is supposed to
initiate a new connection SHOULD initiate it as soon as the offer/ initiate a new connection SHOULD initiate it as soon as the offer/
answer exchange is completed, even if the endpoint does not intend to answer exchange is completed, even if the endpoint does not intend to
immediately begin sending media to the remote endpoint. This allows immediately begin sending media to the remote endpoint. This allows
media to flow from the remote endpoint if needed. media to flow from the remote endpoint if needed.
Typically, endpoints do not close the connection until the session Typically, endpoints do not close the connection until the session
has expired, been explicitly terminated, or a new connid value has has expired, been explicitly terminated, or a new connid value has
been provided for the m= line. Additionaly, specific applications can been provided for the m= line. Additionaly, specific applications can
describe further scenarios where an end-point may close a given describe further scenarios where an end-point may close a given
connection. In case the session is explicitly terminated by one of connection. In case the session is explicitly terminated by one of
the endpoints (e.g., the endpoint sends a SIP [10] BYE), the end the endpoints (e.g., the endpoint sends a SIP [9] BYE), the end point
point terminating the session is responsible for closing the terminating the session is responsible for closing the
transport-connection. transport-connection.
If an endpoint determines that the transport-connection for an m= If an endpoint determines that the transport-connection for an m=
line has been closed and it should be reestablished, it SHOULD line has been closed and it should be reestablished, it SHOULD
perform a new offer/answer exchange using a new connid value for this perform a new offer/answer exchange using a new connid value for this
m= line. m= line.
Note that the SDP direction attribute (e.g., a=sendonly) deals Note that the SDP direction attribute (e.g., a=sendonly) deals
with the media sent over the transport-connection, but has no with the media sent over the transport-connection, but has no
impact on the transport-connection itself. impact on the transport-connection itself.
skipping to change at page 9, line 42 skipping to change at page 10, line 11
a=connid:3 a=connid:3
This will cause the offerer (at 192.0.2.2) to initiate a connection This will cause the offerer (at 192.0.2.2) to initiate a connection
to port 54321 at 192.0.2.1. to port 54321 at 192.0.2.1.
8. Security Considerations 8. Security Considerations
See RFC 2327 [3] for security and other considerations specific to See RFC 2327 [3] for security and other considerations specific to
the Session Description Protocol in general. the Session Description Protocol in general.
An attacker may attempt to modify the values of the connid attributes An attacker may attempt to modify the values of the connid and setup
to have endpoints reestablish connections unnecesaryly. So, it is attributes to have endpoints reestablish connections unnecesaryly or
STRONGLY RECOMMENDED that integrity protection be applied to the SDP to keep them from establishing a connection. So, it is STRONGLY
session descriptions. For session descriptions carried in SIP [10], RECOMMENDED that integrity protection be applied to the SDP session
S/MIME is the natural choice to provide such end-to-end integrity descriptions. For session descriptions carried in SIP [9], S/MIME is
protection, as described in RFC 3261 [10]. Other applications MAY use the natural choice to provide such end-to-end integrity protection,
a different form of integrity protection. as described in RFC 3261 [9]. Other applications MAY use a different
form of integrity protection.
9. IANA Considerations 9. IANA Considerations
This document defines two session and media level SDP attributes: This document defines two session and media level SDP attributes:
setup and connid. Their formats are defined in Section 4 and Section setup and connid. Their formats are defined in Section 4 and Section
5 respectively. These two attributes should be registered by the IANA 5 respectively. These two attributes should be registered by the IANA
on on
http://www.iana.org/assignments/sdp-parameters http://www.iana.org/assignments/sdp-parameters
skipping to change at page 10, line 46 skipping to change at page 11, line 12
[2] Bradner, S., "Key words for use in RFCs to Indicate Requirement [2] Bradner, S., "Key words for use in RFCs to Indicate Requirement
Levels", BCP 14, RFC 2119, March 1997. Levels", BCP 14, RFC 2119, March 1997.
[3] Handley, M. and V. Jacobson, "SDP: Session Description [3] Handley, M. and V. Jacobson, "SDP: Session Description
Protocol", RFC 2327, April 1998. Protocol", RFC 2327, April 1998.
[4] Rosenberg, J. and H. Schulzrinne, "An Offer/Answer Model with [4] Rosenberg, J. and H. Schulzrinne, "An Offer/Answer Model with
Session Description Protocol (SDP)", RFC 3264, June 2002. Session Description Protocol (SDP)", RFC 3264, June 2002.
[5] Yergeau, F., "UTF-8, a transformation format of ISO 10646", STD 11.2 Informative References
63, RFC 3629, November 2003.
11.2 Informational References
[6] Schulzrinne, H., Rao, A. and R. Lanphier, "Real Time Streaming [5] Schulzrinne, H., Rao, A. and R. Lanphier, "Real Time Streaming
Protocol (RTSP)", RFC 2326, April 1998. Protocol (RTSP)", RFC 2326, April 1998.
[7] Dierks, T. and C. Allen, "The TLS Protocol Version 1.0", RFC [6] Dierks, T. and C. Allen, "The TLS Protocol Version 1.0", RFC
2246, January 1999. 2246, January 1999.
[8] Fielding, R., Gettys, J., Mogul, J., Frystyk, H., Masinter, L., [7] Fielding, R., Gettys, J., Mogul, J., Frystyk, H., Masinter, L.,
Leach, P. and T. Berners-Lee, "Hypertext Transfer Protocol -- Leach, P. and T. Berners-Lee, "Hypertext Transfer Protocol --
HTTP/1.1", RFC 2616, June 1999. HTTP/1.1", RFC 2616, June 1999.
[9] Handley, M., Perkins, C. and E. Whelan, "Session Announcement [8] Handley, M., Perkins, C. and E. Whelan, "Session Announcement
Protocol", RFC 2974, October 2000. Protocol", RFC 2974, October 2000.
[10] Rosenberg, J., Schulzrinne, H., Camarillo, G., Johnston, A., [9] Rosenberg, J., Schulzrinne, H., Camarillo, G., Johnston, A.,
Peterson, J., Sparks, R., Handley, M. and E. Schooler, "SIP: Peterson, J., Sparks, R., Handley, M. and E. Schooler, "SIP:
Session Initiation Protocol", RFC 3261, June 2002. Session Initiation Protocol", RFC 3261, June 2002.
[10] Yergeau, F., "UTF-8, a transformation format of ISO 10646", STD
63, RFC 3629, November 2003.
Authors' Addresses Authors' Addresses
David Yon David Yon
Dialout.Net, Inc Dialout.Net, Inc
One Indian Head Plaza One Indian Head Plaza
Nashua, NH 03060 Nashua, NH 03060
USA USA
EMail: yon@dialout.net EMail: yon@dialout.net
Gonzalo Camarillo Gonzalo Camarillo
Ericsson Ericsson
Hirsalantie 11 Hirsalantie 11
Jorvas 02420 Jorvas 02420
Finland Finland
EMail: Gonzalo.Camarillo@ericsson.com EMail: Gonzalo.Camarillo@ericsson.com
Intellectual Property Statement Intellectual Property Statement
 End of changes. 

This html diff was produced by rfcdiff 1.23, available from http://www.levkowetz.com/ietf/tools/rfcdiff/