draft-ietf-ippm-type-p-monitor-03.txt   rfc7750.txt 
Network Working Group J. Hedin Internet Engineering Task Force (IETF) J. Hedin
Internet-Draft G. Mirsky Request for Comments: 7750 G. Mirsky
Updates: 5357 (if approved) S. Baillargeon Updates: 5357 S. Baillargeon
Intended status: Standards Track Ericsson Category: Standards Track Ericsson
Expires: May 7, 2016 November 4, 2015 ISSN: 2070-1721 February 2016
Differentiated Service Code Point and Explicit Congestion Notification Differentiated Service Code Point and Explicit Congestion Notification
Monitoring in Two-Way Active Measurement Protocol (TWAMP) Monitoring in the Two-Way Active Measurement Protocol (TWAMP)
draft-ietf-ippm-type-p-monitor-03
Abstract Abstract
This document describes an optional extension for Two-Way Active This document describes an optional extension for Two-Way Active
Measurement Protocol (TWAMP) allowing the monitoring of the Measurement Protocol (TWAMP) allowing the monitoring of the
Differentiated Service Code Point and Explicit Congestion Differentiated Service Code Point and Explicit Congestion
Notification fields with the TWAMP-Test protocol. Notification fields with the TWAMP-Test protocol.
Status of This Memo Status of This Memo
This Internet-Draft is submitted in full conformance with the This is an Internet Standards Track document.
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months This document is a product of the Internet Engineering Task Force
and may be updated, replaced, or obsoleted by other documents at any (IETF). It represents the consensus of the IETF community. It has
time. It is inappropriate to use Internet-Drafts as reference received public review and has been approved for publication by the
material or to cite them other than as "work in progress." Internet Engineering Steering Group (IESG). Further information on
Internet Standards is available in Section 2 of RFC 5741.
This Internet-Draft will expire on May 7, 2016. Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
http://www.rfc-editor.org/info/rfc7750.
Copyright Notice Copyright Notice
Copyright (c) 2015 IETF Trust and the persons identified as the Copyright (c) 2016 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 Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of (http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License. described in the Simplified BSD License.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Conventions used in this document . . . . . . . . . . . . 3 1.1. Conventions Used in This Document . . . . . . . . . . . . 3
1.1.1. Terminology . . . . . . . . . . . . . . . . . . . . . 3 1.1.1. Terminology . . . . . . . . . . . . . . . . . . . . . 3
1.1.2. Requirements Language . . . . . . . . . . . . . . . . 3 1.1.2. Requirements Language . . . . . . . . . . . . . . . . 3
2. TWAMP Extensions . . . . . . . . . . . . . . . . . . . . . . 3 2. TWAMP Extensions . . . . . . . . . . . . . . . . . . . . . . 3
2.1. Setting Up Connection to Monitor DSCP and ECN . . . . . . 3 2.1. Setting Up Connection to Monitor DSCP and ECN . . . . . . 3
2.2. TWAMP-Test Extension . . . . . . . . . . . . . . . . . . 4 2.2. TWAMP-Test Extension . . . . . . . . . . . . . . . . . . 4
2.2.1. Session-Reflector Packet Format for DSCP and ECN 2.2.1. Session-Reflector Packet Format for DSCP and ECN
Monitoring . . . . . . . . . . . . . . . . . . . . . 4 Monitoring . . . . . . . . . . . . . . . . . . . . . 4
2.2.2. DSCP and ECN Monitoring with RFC 6038 extensions . . 7 2.2.2. DSCP and ECN Monitoring with Extensions from RFC 6038 8
2.2.3. Consideration for TWAMP Light mode . . . . . . . . . 8 2.2.3. Consideration for TWAMP Light Mode . . . . . . . . . 8
3. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 8 3. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 9
4. Security Considerations . . . . . . . . . . . . . . . . . . . 9 4. Security Considerations . . . . . . . . . . . . . . . . . . . 9
5. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 9 5. References . . . . . . . . . . . . . . . . . . . . . . . . . 9
6. References . . . . . . . . . . . . . . . . . . . . . . . . . 9 5.1. Normative References . . . . . . . . . . . . . . . . . . 9
6.1. Normative References . . . . . . . . . . . . . . . . . . 9 5.2. Informative References . . . . . . . . . . . . . . . . . 10
6.2. Informative References . . . . . . . . . . . . . . . . . 10 Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 10
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 10 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 11
1. Introduction 1. Introduction
The One-Way Active Measurement Protocol (OWAMP) [RFC4656] defines the The One-Way Active Measurement Protocol (OWAMP) [RFC4656] defines the
Type-P Descriptor field and negotiation of its value in OWAMP-Control Type-P Descriptor field and negotiation of its value in the OWAMP-
protocol. The Two-Way Active Measurement Protocol (TWAMP) [RFC5357] Control protocol. The Two-Way Active Measurement Protocol (TWAMP)
states that only a Differentiated Services Code Point (DSCP) [RFC5357] states that only a Differentiated Services Code Point
[RFC2474], [RFC3168], [RFC3260] value can be defined by Type-P (DSCP) value (see [RFC2474], [RFC3168], and [RFC3260]) can be defined
Descriptor and the negotiated value must be used by both Session- by Type-P Descriptor, and the negotiated value must be used by both
Sender and Session-Reflector. The TWAMP specification also states the Session-Sender and Session-Reflector. The TWAMP specification
that the same DSCP value (found in the Session-Sender packet) MUST be also states that the same DSCP value (found in the Session-Sender
used in the test packet reflected by the Session-Reflector. However packet) MUST be used in the test packet reflected by the Session-
the TWAMP-Test protocol does not specify any methods to determine or Reflector. However, the TWAMP-Test protocol does not specify any
report when the DSCP value has changed or is different than expected methods to determine or report when the DSCP value has changed or is
in the forward or reverse direction. Re-marking the DSCP (changing different than expected in the forward or reverse direction. Re-
its original value) in IP networks is possible and often accomplished marking the DSCP (changing its original value) in IP networks is
by a Differentiated Services policy configured on a single node along possible and often accomplished by a Differentiated Services policy
the IP path. In many cases, a change of the DSCP value indicates an configured on a single node along the IP path. In many cases, a
unintentional or erroneous behavior. At best, the Session-Sender can change of the DSCP value indicates an unintentional or erroneous
detect a change of the DSCP reverse direction assuming such change is behavior. At best, the Session-Sender can detect a change of the
actually detectable. DSCP reverse direction, assuming such a change is actually
detectable.
This document describes an OPTIONAL feature for TWAMP. It is called This document describes an OPTIONAL feature for TWAMP. It is called
the DSCP and ECN Monitoring. It allows the Session-Sender to know DSCP and ECN Monitoring. It allows the Session-Sender to know the
the actual DSCP value received at the Session-Reflector. Furthermore actual DSCP value received at the Session-Reflector. Furthermore,
this feature tracks the Explicit Congestion Notification (ECN) this feature tracks the Explicit Congestion Notification (ECN) value
[RFC2474], [RFC3168], [RFC3260] value received at the Session- (see [RFC2474], [RFC3168], and [RFC3260]) received at the Session-
Reflector. This is helpful to determine if ECN is actually operating Reflector. This is helpful to determine if the ECN is actually
or if an ECN-capable node has detected congestion in the forward operating or if an ECN-capable node has detected congestion in the
direction. forward direction.
1.1. Conventions used in this document 1.1. Conventions Used in This Document
1.1.1. Terminology 1.1.1. Terminology
DSCP: Differentiated Services Code Point DSCP: Differentiated Services Code Point
ECN: Explicit Congestion Notification ECN: Explicit Congestion Notification
IPPM: IP Performance Measurement IPPM: IP Performance Metrics
TWAMP: Two-Way Active Measurement Protocol TWAMP: Two-Way Active Measurement Protocol
OWAMP: One-Way Active Measurement Protocol OWAMP: One-Way Active Measurement Protocol
1.1.2. Requirements Language 1.1.2. Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in "OPTIONAL" in this document are to be interpreted as described in
[RFC2119]. [RFC2119].
2. TWAMP Extensions 2. TWAMP Extensions
TWAMP connection establishment follows the procedure defined in TWAMP connection establishment follows the procedure defined in
Section 3.1 of [RFC4656] and Section 3.1 of [RFC5357] where the Modes Section 3.1 of [RFC4656] and Section 3.1 of [RFC5357] where the Modes
field is used to identify and select specific communication field is used to identify and select specific communication
capabilities. At the same time the Modes field been recognized and capabilities. At the same time, the Modes field is recognized and
used as an extension mechanism [RFC6038]. The new feature requires a used as an extension mechanism [RFC6038]. The new feature requires a
new flag to identify the ability of a Session-Reflector to return new flag to identify the ability of a Session-Reflector to return the
value of received DSCP and ECN values back to a Session-Sender, and values of received DSCP and ECN values back to a Session-Sender, and
to support the new Session-Reflector packet format in the TWAMP-Test to support the new Session-Reflector packet format in the TWAMP-Test
protocol. See the Section 3 for details on the assigned bit protocol. See Section 3 for details on the assigned bit position.
position.
2.1. Setting Up Connection to Monitor DSCP and ECN 2.1. Setting Up Connection to Monitor DSCP and ECN
The Server sets the DSCP and ECN Monitoring flag in the Modes field The Server sets the DSCP and ECN Monitoring flag in the Modes field
of the Server Greeting message to indicate its capabilities and of the Server Greeting message to indicate its capabilities and
willingness to monitor them. If the Control-Client agrees to monitor willingness to monitor them. If the Control-Client agrees to monitor
DSCP and ECN on some or all test sessions invoked with this control DSCP and ECN on some or all test sessions invoked with this control
connection, it MUST set the DSCP and ECN Monitoring flag in the Modes connection, it MUST set the DSCP and ECN Monitoring flag in the Modes
field in the Setup Response message. field in the Setup Response message.
2.2. TWAMP-Test Extension 2.2. TWAMP-Test Extension
Monitoring of DSCP and ECN requires support by the Session-Reflector Monitoring of DSCP and ECN requires support by the Session-Reflector
and changes the test packet format in all the original and changes the test packet format in all the original modes
(unauthenticated, authenticated and encrypted) modes. Monitoring of (unauthenticated, authenticated, and encrypted). Monitoring of DSCP
DSCP and ECN does not alter the Session-Sender test packet format but and ECN does not alter the Session-Sender test packet format, but
certain considerations must be taken when and if this mode is certain considerations must be taken when and if this mode is
accepted in combination with Symmetrical Size mode [RFC6038]. accepted in combination with Symmetrical Size mode [RFC6038].
2.2.1. Session-Reflector Packet Format for DSCP and ECN Monitoring 2.2.1. Session-Reflector Packet Format for DSCP and ECN Monitoring
When the Session-Reflector supports DSCP and ECN Monitoring it When the Session-Reflector supports DSCP and ECN Monitoring, it
constructs the Sender DSCP and ECN (S-DSCP-ECN) field, presented in constructs the Sender DSCP and ECN (S-DSCP-ECN) field, presented in
Figure 1, for each test packet it sends to Session-Sender according Figure 1, for each test packet it sends to the Session-Sender
to the following procedure: according to the following procedure:
o the six (least-significant) bits of the Differentiated Service o the six (least-significant) bits of the Differentiated Service
field MUST be copied from received Session-Sender test packet into field MUST be copied from the received Session-Sender test packet
Sender DSCP (S-DSCP) field; into the Sender DSCP (S-DSCP) field;
o the two bits of the ECN field MUST be copied from received o the two bits of the ECN field MUST be copied from the received
Session-Sender test packet into Sender ECN (S-ECN) field. Session-Sender test packet into the Sender ECN (S-ECN) field.
0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7
+---+---+---+---+---+---+---+---+ +---+---+---+---+---+---+---+---+
| S-DSCP | S-ECN | | S-DSCP | S-ECN |
+---+---+---+---+---+---+---+---+ +---+---+---+---+---+---+---+---+
Figure 1: Sender DSCP and ECN field format Figure 1: Sender DSCP and ECN Field Format
Formats of the test packet transmitted by the Session-Reflector in Formats of the test packet transmitted by the Session-Reflector in
unauthenticated, authenticated and encrypted modes been defined in unauthenticated, authenticated, and encrypted modes have been defined
Section 4.2.1 [RFC5357]. For the Session-Reflector that supports in Section 4.2.1 of [RFC5357]. For the Session-Reflector that
DSCP and ECN Monitoring these formats are displayed in Figure 2 and supports DSCP and ECN Monitoring, these formats are displayed in
Figure 3. Figures 2 and 3.
For unauthenticated mode: For unauthenticated mode:
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sequence Number | | Sequence Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Timestamp | | Timestamp |
| | | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Error Estimate | MBZ | | Error Estimate | MBZ |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Receive Timestamp | | Receive Timestamp |
| | | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sender Sequence Number | | Sender Sequence Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sender Timestamp | | Sender Timestamp |
| | | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sender Error Estimate | MBZ | | Sender Error Estimate | MBZ |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sender TTL | S-DSCP-ECN | MBZ | | Sender TTL | S-DSCP-ECN | MBZ |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | | |
~ Packet Padding ~ ~ Packet Padding ~
| | | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 2: Session-Reflector test packet format with DSCP and ECN Figure 2: Session-Reflector Test Packet Format with DSCP and ECN
Monitoring in unauthenticated mode Monitoring in Unauthenticated Mode
The DSCP and ECN values (part of the Type-P Descriptor [RFC4656]) can The DSCP and ECN values (part of the Type-P Descriptor [RFC4656]) can
be provisioned through TWAMP-Control or by other means (CLI or be provisioned through TWAMP-Control or by other means (command-line
Central Controller). The DSCP and ECN values are often copied into interface (CLI) or Central Controller). The DSCP and ECN values are
reflected test packets with current TWAMP implementations without often copied into reflected test packets with current TWAMP
TWAMP-Control protocol. With DSCP and ECN Monitoring Extension, the implementations without TWAMP-Control protocol. With the DSCP and
Session-Reflector handles DSCP as following: ECN Monitoring extension, the Session-Reflector handles the DSCP as
follows:
o the Session-Reflector MUST extract the DSCP and ECN values from o the Session-Reflector MUST extract the DSCP and ECN values from
the received packet and MUST populate with them S-DSCP-ECN field the received packet and MUST use them to populate the S-DSCP-ECN
of the corresponding reflected packet; field of the corresponding reflected packet;
o the Session-Reflector MUST transmit each reflected test packet o the Session-Reflector MUST transmit each reflected test packet
with DSCP set to the provisioned value; with the DSCP set to the provisioned value;
o if the provisioned DSCP value is not known (e.g. TWAMP Light), o if the provisioned DSCP value is not known (e.g., TWAMP Light),
the choice of the DSCP is implementation specific. For instance, the choice of the DSCP is implementation specific. For instance,
Session-Reflector MAY copy the DSCP value from the received test the Session-Reflector MAY copy the DSCP value from the received
packet and set it as DSCP in a reflected packet. Alternatively test packet and set it as the DSCP in a reflected packet.
Session-Reflector MAY set DSCP value to CS0 (zero) [RFC2474]; Alternatively, the Session-Reflector MAY set the DSCP value to CS0
(zero) [RFC2474];
o if the provisioned ECN value is not known, ECN SHOULD be set to o if the provisioned ECN value is not known, ECN SHOULD be set to
Not-ECT codepoint value [RFC3168]. Otherwise, the provisioned ECN Not-ECT codepoint value [RFC3168]. Otherwise, the provisioned ECN
value for the session SHALL be used. value for the session SHALL be used.
A Session-Reflector in the DSCP and ECN Monitoring mode does not A Session-Reflector in the DSCP and ECN Monitoring mode does not
analyze, nor acts on ECN value of the received TWAMP test packet and analyze nor act on the ECN value of the received TWAMP test packet;
therefore ignores congestion indications from the network. It is therefore, it ignores congestion indications from the network. It is
expected that sending rates are low enough, as TWAMP deployment expected that sending rates are low enough, as TWAMP deployment
experience had demonstrated since TWAMP base RFC 5357 publication in experience had demonstrated since TWAMP base (RFC 5357) was published
2008, that ignoring these congestion indications will not in 2008, that ignoring these congestion indications will not
significantly contribute to network congestion. significantly contribute to network congestion.
For authenticated and encrypted modes: For authenticated and encrypted modes:
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sequence Number | | Sequence Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | | |
| MBZ (12 octets) | | MBZ (12 octets) |
| | | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Timestamp | | Timestamp |
| | | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Error Estimate | | | Error Estimate | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +
| MBZ (6 octets) | | MBZ (6 octets) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Receive Timestamp | | Receive Timestamp |
| | | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| MBZ (8 octets) | | MBZ (8 octets) |
| | | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sender Sequence Number | | Sender Sequence Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | | |
| MBZ (12 octets) | | MBZ (12 octets) |
| | | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sender Timestamp | | Sender Timestamp |
| | | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sender Error Estimate | | | Sender Error Estimate | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +
| MBZ (6 octets) | | MBZ (6 octets) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sender TTL | S-DSCP-ECN | | | Sender TTL | S-DSCP-ECN | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +
| | | |
| MBZ (14 octets) | | MBZ (14 octets) |
| | | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | | |
| HMAC (16 octets) | | HMAC (16 octets) |
| | | |
| | | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | | |
~ Packet Padding ~ ~ Packet Padding ~
| | | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 3: Session-Reflector test packet format with DSCP and ECN Figure 3: Session-Reflector Test Packet Format with DSCP and ECN
Monitoring in authenticated or encrypted modes Monitoring in Authenticated or Encrypted Modes
2.2.2. DSCP and ECN Monitoring with RFC 6038 extensions 2.2.2. DSCP and ECN Monitoring with Extensions from RFC 6038
[RFC6038] defined two extensions to TWAMP. First, to ensure that [RFC6038] defined two extensions to TWAMP -- first, to ensure that
Session-Sender and Session-Reflector exchange TWAMP-Test packets of the Session-Sender and Session-Reflector exchange TWAMP-Test packets
equal size. Second, to specify number of octets to be reflected by of equal size; second, to specify the number of octets to be
Session-Reflector. If DSCP and ECN Monitoring and Symmetrical Size reflected by Session-Reflector. If DSCP and ECN Monitoring and
and/or Reflects Octets modes are being negotiated between Server and Symmetrical Size and/or Reflects Octets modes are being negotiated
Control-Client in Unauthenticated mode, then, because Sender DSCP and between Server and Control-Client in Unauthenticated mode, then,
Sender ECN increase size of unauthenticated Session-Reflector packet because Sender DSCP and Sender ECN increase the size of the
by 4 octets, the Padding Length value SHOULD be >= 28 octets to allow unauthenticated Session-Reflector packet by 4 octets, the Padding
Length value SHOULD be greater than or equal to 28 octets to allow
for the truncation process that TWAMP recommends in Section 4.2.1 of for the truncation process that TWAMP recommends in Section 4.2.1 of
[RFC5357]. [RFC5357].
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sequence Number | | Sequence Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Timestamp | | Timestamp |
| | | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Error Estimate | | | Error Estimate | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +
| | | |
| MBZ (28 octets) | | MBZ (28 octets) |
| | | |
+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | | | | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +
| | | |
. . . .
. Packet Padding . . Packet Padding .
| | | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 4: Session-Sender test packet format with DSCP and ECN Figure 4: Session-Sender Test Packet Format with DSCP and ECN
Monitoring and Symmetrical Test Packet in unauthenticated mode Monitoring and Symmetrical Test Packet in Unauthenticated Mode
2.2.3. Consideration for TWAMP Light mode 2.2.3. Consideration for TWAMP Light Mode
Appendix I of [RFC5357] does not explicitly state how the value of Appendix I of [RFC5357] does not explicitly state how the value of
the Type-P Descriptor is synchronized between Session-Sender and the Type-P Descriptor is synchronized between the Session-Sender and
Session-Reflector and whether different values are considered as Session-Reflector and whether different values are considered as
error condition and SHOULD be reported. We assume that by some means error conditions and should be reported. We assume that by some
the Session-Sender and the Session-Reflector of the given TWAMP-Test means the Session-Sender and the Session-Reflector of the given
session been informed to use the same DSCP value. Same means, i.e. TWAMP-Test session have been informed to use the same DSCP value.
configuration, could be used to inform Session-Reflector to support The same means, i.e., configuration, could be used to inform the
DSCP and ECN Monitoring mode by copying data from received TWAMP test Session-Reflector to support DSCP and ECN Monitoring mode by copying
packets. Then Session-Sender may be informed to use Sender DSCP and data from received TWAMP test packets. Then Session-Sender may be
ECN field in reflected TWAMP test packet. informed to use the Sender DSCP and ECN field in the reflected TWAMP
test packet.
3. IANA Considerations 3. IANA Considerations
The TWAMP-Modes registry defined in [RFC5618]. In the TWAMP-Modes registry defined in [RFC5618], IANA has reserved a
new DSCP and ECN Monitoring Capability as follows:
IANA is requested to reserve a new DSCP and ECN Monitoring Capability
as follows:
+-----+------------------------+---------------------+--------------+ +-----+---------------------------+---------------------+-----------+
| Bit | Description | Semantics | Reference | | Bit | Description | Semantics | Reference |
| | | Definition | | | Pos | | Definition | |
+-----+------------------------+---------------------+--------------+ +-----+---------------------------+---------------------+-----------+
| TBA | DSCP and ECN | Section 2 | This | | 8 | DSCP and ECN Monitoring | Section 2 | RFC 7750 |
| | Monitoring Capability | | document | | | Capability | | |
+-----+------------------------+---------------------+--------------+ +-----+---------------------------+---------------------+-----------+
Table 1: New Type-P Descriptor Monitoring Capability Table 1: New Type-P Descriptor Monitoring Capability
4. Security Considerations 4. Security Considerations
Monitoring of DSCP and ECN does not appear to introduce any Monitoring of DSCP and ECN does not appear to introduce any
additional security threat to hosts that communicate with TWAMP as additional security threat to hosts that communicate with TWAMP as
defined in [RFC5357], and existing extensions [RFC6038]. Sections defined in [RFC5357] and existing extensions [RFC6038]. Sections
such as 3.2, 4., 4.1.2, 4.2, and 4.2.1 of [RFC5357] discuss such as 3.2, 4, 4.1.2, 4.2, and 4.2.1 of [RFC5357] discuss
unauthenticated, authenticated, and encrypted modes in varying unauthenticated, authenticated, and encrypted modes in varying
degrees of detail. The security considerations that apply to any degrees of detail. The security considerations that apply to any
active measurement of live networks are relevant here as well. See active measurement of live networks are relevant here as well. See
the Security Considerations sections in [RFC4656] and [RFC5357]. the Security Considerations sections in [RFC4656] and [RFC5357].
5. Acknowledgements 5. References
Authors greatly appreciate thorough review and thoughtful comments by
Bill Cerveny, Christofer Flinta and Samita Chakrabarti.
6. References
6.1. Normative References 5.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997, DOI 10.17487/RFC2119, March 1997,
<http://www.rfc-editor.org/info/rfc2119>. <http://www.rfc-editor.org/info/rfc2119>.
[RFC2474] Nichols, K., Blake, S., Baker, F., and D. Black, [RFC2474] Nichols, K., Blake, S., Baker, F., and D. Black,
"Definition of the Differentiated Services Field (DS "Definition of the Differentiated Services Field (DS
Field) in the IPv4 and IPv6 Headers", RFC 2474, Field) in the IPv4 and IPv6 Headers", RFC 2474,
DOI 10.17487/RFC2474, December 1998, DOI 10.17487/RFC2474, December 1998,
skipping to change at page 10, line 25 skipping to change at page 10, line 30
[RFC5618] Morton, A. and K. Hedayat, "Mixed Security Mode for the [RFC5618] Morton, A. and K. Hedayat, "Mixed Security Mode for the
Two-Way Active Measurement Protocol (TWAMP)", RFC 5618, Two-Way Active Measurement Protocol (TWAMP)", RFC 5618,
DOI 10.17487/RFC5618, August 2009, DOI 10.17487/RFC5618, August 2009,
<http://www.rfc-editor.org/info/rfc5618>. <http://www.rfc-editor.org/info/rfc5618>.
[RFC6038] Morton, A. and L. Ciavattone, "Two-Way Active Measurement [RFC6038] Morton, A. and L. Ciavattone, "Two-Way Active Measurement
Protocol (TWAMP) Reflect Octets and Symmetrical Size Protocol (TWAMP) Reflect Octets and Symmetrical Size
Features", RFC 6038, DOI 10.17487/RFC6038, October 2010, Features", RFC 6038, DOI 10.17487/RFC6038, October 2010,
<http://www.rfc-editor.org/info/rfc6038>. <http://www.rfc-editor.org/info/rfc6038>.
6.2. Informative References 5.2. Informative References
[RFC3260] Grossman, D., "New Terminology and Clarifications for [RFC3260] Grossman, D., "New Terminology and Clarifications for
Diffserv", RFC 3260, DOI 10.17487/RFC3260, April 2002, Diffserv", RFC 3260, DOI 10.17487/RFC3260, April 2002,
<http://www.rfc-editor.org/info/rfc3260>. <http://www.rfc-editor.org/info/rfc3260>.
Acknowledgements
The authors greatly appreciate thorough review and thoughtful
comments by Bill Cerveny, Christofer Flinta, and Samita Chakrabarti.
Authors' Addresses Authors' Addresses
Jonas Hedin Jonas Hedin
Ericsson Ericsson
Email: jonas.hedin@ericsson.com Email: jonas.hedin@ericsson.com
Greg Mirsky Greg Mirsky
Ericsson Ericsson
 End of changes. 48 change blocks. 
227 lines changed or deleted 225 lines changed or added

This html diff was produced by rfcdiff 1.42. The latest version is available from http://tools.ietf.org/tools/rfcdiff/