MNA for Performance Measurement with Alternate Marking Method

Abstract

MPLS Network Action (MNA) is used to indicate action for Label Switched Paths (LSPs) and/or MPLS packets and to transfer data needed for the action.¶

This document defines MNA encoding for MPLS performance measurement with alternate marking method, which performs flow-based packet loss, delay, and jitter measurements on MPLS live traffic.¶

1. Introduction

MPLS Network Action (MNA) is used to indicate action for Label Switched Paths (LSPs) and/or MPLS packets and to transfer data needed for the action.¶

To addressing the MNA requirements [I-D.ietf-mpls-mna-requirements] and by following the MNA framework [I-D.ietf-mpls-mna-fwk], [I-D.ietf-mpls-mna-hdr] defines the MNA sub-stack solution for carrying Network Actions and Ancillary Data in the label stack.¶

As specified in [I-D.ietf-mpls-inband-pm-encapsulation], Flow-ID Label, L bit and D bit are used for MPLS flow identification and flow-based performance measurement with alternate marking method, which can be an applicable MNA usecase [I-D.ietf-mpls-mna-usecases].¶

This document defines MNA encoding for MPLS performance measurement with alternate marking method, which performs flow-based packet loss, delay, and jitter measurements on MPLS live traffic. The proposed MNA encoding is compliant with the MNA sub-stack solution specified in [I-D.ietf-mpls-mna-hdr] and reuses the data fields specified in [I-D.ietf-mpls-inband-pm-encapsulation].¶

2. MPLS Network Action for Flow-based PM

The MNA format for performance measurement with alternate marking method is illustrated as below:¶

 0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|   Opcode=3  |    Bit-Position=TBA1    |R|IHS|S| Res |U| NASL=1|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|1|                Flow-ID                |L|D|S|    Reserved   |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

The description of MNA for Alternate Marking is as follows:¶

• Name: Performance Measurement with Alternate Marking Method (PMAMM) Action.¶
• Network Action Indication: The PMAMM Action indication is bit position TBA1.¶
• Scope: The PMAMM Action is valid in all scopes.¶
• In-Stack Data: The PMAMM Action carries 30 bits of ancillary data. The most significant 20 bits of ancillary data is the Flow-ID Value, immediately followed by L bit and D bit. The least significant 8 bits of ancillary data is reserved. The three fields Flow-ID Value, L bit and D bit have semantics consistent with the Flow-ID Label, L bit and D bit defined in [I-D.ietf-mpls-inband-pm-encapsulation]. While the Flow-ID Label has some restrictions to avoid collisions with the reserved label space (0-15) [RFC3032], those restrictions are not necessary for the Flow-ID Value and do not apply. The forwarding node in the scope of PMAMM Action SHOULD execute flow-based performance measurement by using the Flow-ID Value, L bit and D bit.¶
• Post-Stack Data: None.¶

Ed.note: There is ongoing discussion in MPLS mailing list on whether to omit "Flag-based NAI with AD" from [I-D.ietf-mpls-mna-hdr], if the WG decision is to omit "Flag-based NAI with AD", then the MNA format described above would be changed from "Flag-based NAI with AD" to "New Opcode with AD".¶

3. Security Considerations

Security issues discussed in [I-D.ietf-mpls-inband-pm-encapsulation] and [I-D.ietf-mpls-mna-hdr] apply to this document.¶

4. IANA Considerations

This document requests that IANA allocate a bit position (TBA1) from the MPLS "In-Stack MPLS Network Action Indicator Flags" registry for the Performance Measurement with Alternate Marking Method Action. Specifically, this document requests the following allocation from IANA.¶

MNA Flag    Bit-Position    Description
--------    ------------    -----------
   P            TBA1        PM with Alternate Marking Method

5. Acknowledgements

To be added.¶

6. References