| MPLS | D. Frost, Ed. |
| Internet-Draft | S. Bryant, Ed. |
| Intended status: Informational | Cisco Systems |
| Expires: January 20, 2012 | July 19, 2011 |
A Packet Loss and Delay Measurement Profile for MPLS-based Transport Networks
draft-ietf-mpls-tp-loss-delay-profile-04
Procedures and protocol mechanisms to enable efficient and accurate measurement of packet loss, delay, and throughput in MPLS networks are defined in RFC XXXX.
The MPLS Transport Profile (MPLS-TP) is the set of MPLS protocol functions applicable to the construction and operation of packet- switched transport networks.
This document describes a profile of the general MPLS loss, delay, and throughput measurement techniques that suffices to meet the specific requirements of MPLS-TP.
This document is a product of a joint Internet Engineering Task Force (IETF) / International Telecommunication Union Telecommunication Standardization Sector (ITU-T) effort to include an MPLS Transport Profile within the IETF MPLS and Pseudowire Emulation Edge-to-Edge (PWE3) architectures to support the capabilities and functionalities of a packet transport network as defined by the ITU-T.
This Informational Internet-Draft is aimed at achieving IETF Consensus before publication as an RFC and will be subject to an IETF Last Call.
[RFC Editor, please remove this note before publication as an RFC and insert the correct Streams Boilerplate to indicate that the published RFC has IETF consensus.]
[RFC Editor, please replace XXXX with the RFC number assigned to draft-ietf-mpls-loss-delay.]
This Internet-Draft is submitted in full conformance with the 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 and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress."
This Internet-Draft will expire on January 20, 2012.
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Procedures for the measurement of packet loss, delay, and throughput in MPLS networks are defined in [I-D.ietf-mpls-loss-delay]. This document describes a profile, i.e. a simplified subset, of these procedures that suffices to meet the specific requirements of MPLS-based transport networks [RFC5921] as defined in [RFC5860]. This profile is presented for the convenience of implementors who are concerned exclusively with the transport network context.
The use of the profile specified in this document is purely optional. Implementors wishing to provide enhanced functionality that is within the scope of [I-D.ietf-mpls-loss-delay] but outside the scope of this profile may do so, whether or not the implementation is restricted to the transport network context.
The assumption of this profile is that the devices involved in a measurement operation are configured for measurement by a means external to the measurement protocols themselves, for example via a Network Management System (NMS) or separate configuration protocol. The manageability considerations in [I-D.ietf-mpls-loss-delay] apply, and further information on MPLS-TP network management can be found in [RFC5950].
This document is a product of a joint Internet Engineering Task Force (IETF) / International Telecommunication Union Telecommunication Standardization Sector (ITU-T) effort to include an MPLS Transport Profile within the IETF MPLS and Pseudowire Emulation Edge-to-Edge (PWE3) architectures to support the capabilities and functionalities of a packet transport network as defined by the ITU-T.
The measurement considerations discussed in Section 2.9 of [I-D.ietf-mpls-loss-delay] apply also in the context of MPLS-TP, except for the following, which pertain to topologies excluded from MPLS-TP:
When an LM session is externally configured, the values of several protocol parameters can be fixed in advance at the endpoints involved in the session, so that negotiation of these parameters is not required. These parameters, and their default values as specified by this profile, are as follows:
| Parameter | Default Value |
|---|---|
| Query control code | In-band response requested |
| Byte/packet Count (B) Flag | Packet count |
| Traffic-Class-specific (T) Flag | Traffic-class-scoped |
| Origin Timestamp Format (OTF) | Truncated IEEE 1588v2 |
A simple implementation may assume that external configuration will ensure that both ends of the communication are using the default values for these parameters. Implementations are, however, strongly advised to validate the values of these parameters in received messages so that configuration inconsistencies can be detected and reported.
LM message rates (and test message rates, when inferred LM is used) should be configurable by the network operator on a per-channel basis. The following intervals should be supported:
| Message Type | Supported Intervals |
|---|---|
| LM Message | 100 milliseconds, 1 second, 10 seconds, 1 minute, 10 minutes |
| Test Message | 10 milliseconds, 100 milliseconds, 1 second, 10 seconds, 1 minute |
When a DM session is externally configured, the values of several protocol parameters can be fixed in advance at the endpoints involved in the session, so that negotiation of these parameters is not required. These parameters, and their default values as specified by this profile, are as follows:
| Parameter | Default Value |
|---|---|
| Query control code | In-band response requested |
| Querier Timestamp Format (QTF) | Truncated IEEE 1588v2 |
| Responder Timestamp Format (RTF) | Truncated IEEE 1588v2 |
| Responder's Preferred Timestamp Format (RPTF) | Truncated IEEE 1588v2 |
This profile uses the MPLS Delay Measurement (DM) Channel Type in the Associated Channel Header (ACH).
A simple implementation may assume that external configuration will ensure that both ends of the communication are using the default values for these parameters. Implementations are, however, strongly advised to validate the values of these parameters in received messages so that configuration inconsistencies can be detected and reported.
DM message rates should be configurable by the network operator on a per-channel basis. The following message intervals should be supported: 1 second, 10 seconds, 1 minute, 10 minutes.
This document delineates a subset of the procedures specified in [I-D.ietf-mpls-loss-delay], and as such introduces no new security considerations in itself. The security considerations discussed in [I-D.ietf-mpls-loss-delay] apply also to the profile presented in this document. General considerations for MPLS-TP network security can be found in [I-D.ietf-mpls-tp-security-framework].
This document introduces no new IANA considerations.
| [RFC5586] | Bocci, M., Vigoureux, M. and S. Bryant, "MPLS Generic Associated Channel", RFC 5586, June 2009. |
| [RFC5860] | Vigoureux, M., Ward, D. and M. Betts, "Requirements for Operations, Administration, and Maintenance (OAM) in MPLS Transport Networks", RFC 5860, May 2010. |
| [I-D.ietf-mpls-loss-delay] | Frost, D and S Bryant, "Packet Loss and Delay Measurement for MPLS Networks", Internet-Draft draft-ietf-mpls-loss-delay-04, July 2011. |
| [RFC5921] | Bocci, M., Bryant, S., Frost, D., Levrau, L. and L. Berger, "A Framework for MPLS in Transport Networks", RFC 5921, July 2010. |
| [RFC5950] | Mansfield, S., Gray, E. and K. Lam, "Network Management Framework for MPLS-based Transport Networks", RFC 5950, September 2010. |
| [I-D.ietf-mpls-tp-security-framework] | Fang, L, Niven-Jenkins, B, Mansfield, S and R Graveman, "MPLS-TP Security Framework", Internet-Draft draft-ietf-mpls-tp-security-framework-02, October 2011. |