Subject: [mpls] Looking for comments of the suggestion to allow LSP Ping Reply to reflect the impairment condition of the downstream link

From: Linda Dunbar <[email-masked]>
Date: Wed, 03 Mar 2010 14:15:44 -0600

Dear all, 

We have submitted a draft to suggest allowing transit LSR to indicate
downstream link impairment condition in the LPS Ping Reply. A common example
for the link condition impairment is the bandwidth fluctuation in Mobile
Backhaul network, where Microwave transport is widely deployed. Microwave
transport node's Adaptive Modulation will adjust its bandwidth based on the
weather.  In some network environment, source node also needs to know the
condition of the link on which the LSPs are carried even though the link
connectivity is up.  That way the source LSR can perform needed functions,
such as enforcing admission control, re-signal and/or re-compute the LSP
path, or generate more stringent performance monitoring at shorter interval,
and etc.  

We are looking for comments and suggestions. 

http://tools.ietf.org/id/draft-dunbar-so-mpls-detect-impair-mplsping-01.txt

Thanks, Linda Dunbar

Advanced Technology Dept, Wireline Networks,

Huawei Technologies, Inc.

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From: Greg Mirsky <[email-masked]>
Date: Wed, 3 Mar 2010 13:44:34 -0800

Dear Linda, Authors, Editors, and All,
below are my comments on the document:

   - Section 1. Motivation, p.2. Formerly known EXP-bits are now referred as
   TC-bits
   - Section 2.3, p.5 I'm not familiar with meaning of "HAVE TO", as it it
   is not specified in RFC 2119. Considering that there's is no capability
   negotiation and thus it is unknown whether destination node supports
   Downstream Link Condition reporting I'd suggest use "MAY" instead of "HAVE
   TO". That will make C-bit optional. If you consider it mandatory, then
   destination that does not support this request may reply with Errored TLV
   according to Section 3.7 RFC 4379 indicating that node does not support
   C-bit. I think that mandatory/optional character of the proposed request
   must be defined and proper processing by non-compliant node described.

Regards,
Greg

On Wed, Mar 3, 2010 at 12:15 PM, Linda Dunbar <[email-masked]> wrote:

> transport node’s Adaptive Modulation will adjust its bandwidth based on the
> _______________________________________________
> mpls mailing list
> [email-masked]
> https://www.ietf.org/mailman/listinfo/mpls
>
>

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From: Linda Dunbar <[email-masked]>
Date: Thu, 04 Mar 2010 17:52:22 -0600

Greg, 

Thank you very much for the suggestion. We will make the change for next
revision. 

Linda

  _____  

From: Greg Mirsky [mailto:[email-masked]] 
Sent: Wednesday, March 03, 2010 3:45 PM
To: Linda Dunbar
Cc: [email-masked]; So, Ning; [email-masked];
[email-masked]
Subject: Re: [mpls] Looking for comments of the suggestion to allow LSP
PingReply to reflect the impairment condition of the downstream link

*         Section 1. Motivation, p.2. Formerly known EXP-bits are now
referred as TC-bits

*         Section 2.3, p.5 I'm not familiar with meaning of "HAVE TO", as it
it is not specified in RFC 2119. Considering that there's is no capability
negotiation and thus it is unknown whether destination node supports
Downstream Link Condition reporting I'd suggest use "MAY" instead of "HAVE
TO". That will make C-bit optional. If you consider it mandatory, then
destination that does not support this request may reply with Errored TLV
according to Section 3.7 RFC 4379 indicating that node does not support
C-bit. I think that mandatory/optional character of the proposed request
must be defined and proper processing by non-compliant node described.

Regards,
Greg

Dear all, 

 

Thanks, Linda Dunbar