Detect MPLS Data Path Impairment Using MPLS PING

draft-dunbar-so-mpls-detect-impair-mplsping01

Linda Dunbar (ldunbar@huawei.com)Ning So (ning.so@verizonbusiness.com)

Philippe Niger (philippe.niger@orange-ftgroup.com)Yannick Le Goff (yannick1.legoff@orange-ftgroup.com)

Example of MPLS Network for Mobile backhaul

Base Station

fiber

microwave

RNC

BSC

SGW

End to end MPLS Path

Time

256QAM 128QAM 64QAM 32QAM 16QAM QPSK

256QAM

An example QPSK 16QAM 32QAM 64QAM 128QAM 256QAM

56MHz Channel bandwidth

100Mbps 200Mbps 250Mbps 300Mbps 250Mbps 400Mbps

Adaptive Modulation

Why source node needs to know the Impairment along the MPLS path?

Step 3- Action: Source node can apply more stringent policy control to reduce the incoming traffic, or switch to other optimal path.

microwave

End to end MPLS Path

Step 1- Event: When source node detects its performance to the destination is not as good as expected

End to End PM

Step 2 – Trigger: source node can use MPLS Ping to find out if the poor performance is transient or as the result of other condition (which may last more than a day or hours) or result of switching to none optimal path

Minor change to RFC 4379 can make it possible

• Exact the same mode of operation as RFC 4379 (Echo Request and Echo Reply)

• Same Echo Request:– RFC4379 already defines I bit and N bit out of the octet DS Flags. This draft suggests adding a new bit C for source LSR to

indicate if it desires to have the link impairment condition to be reported by transit LSR in the Echo Reply.

• Same Echo Reply with an additional sub-TLV “Downstream Link Condition” to indicate the condition of the downstream link of the corresponding interface. Sub-Type Value Field

-------- --------

TBD Multipath data (specified by [MPLS-Ping-Enhanced])

TBD Label stack (specified by [MPLS-Ping-Enhanced])

TBD FEC Stack change (specified by [MPLS-Ping-Enhanced])

TBD Downstream Link Condition (new)

S Transit node

Echo Request

Echo Reply Impaired link

Sub-TLV suggestion

• Downstream Link Condition sub-TLV 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Length |ImpairmentTyp | SeverityLevel | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

• The Impairment Type field can take one of the following values:Value Meaning

-------- -------------------1 port towards downstream LSR is congested2 Bandwidth of the link towards downstream LSR is reduced3 performance of the link towards downstream LSR is reduced4 transport media of the link towards downstream LSR has been changed

• The Severity Level field is a value indicating the severity of the impairment. Network operator can set the Severity Level for anticipated conditions and configure the proper actions at the source node upon receiving the Echo Reply.