Subject: [mpls-tp] Comments on draft-ietf-mpls-tp-fault-01

From: "Rafi Ram" <[email-masked]>
Date: Thu, 24 Jun 2010 11:45:02 +0300

Dear Authors,

I would like to propose addition of a new message type "Link Condition
Indication" (LCI).

The LCI message can have the following impairment flags (in the spirit
of draft-dunbar-so-mpls-detect-impair-mplsping-01
<http://tools.ietf.org/html/draft-dunbar-so-mpls-detect-impair-mplsping-
01.txt> ) :

(1) Link performance is reduced (i.e. signal degraded)

(2) Link is congested

(3) Link rate is reduced

A possible motivation for this message may be based on signal degrade
detection at LSR (e.g. based on SONET/SDH/OTN link FEC indications), and
relay of this condition to the LSP protection state machine (APS).

Using the existing LDI message for conveying SD may have the following
drawbacks :

1. It does not allow the flexibility to report of various impairment
conditions

2. Need to differentiate between "link down" condition (equivalent to
SF) and "link reduced" (equivalent to SD), since for APS state machine
SF has higher priority than SD

Best regards,

Rafi