Subject: Re: [mpls] Comments on draft-cheng-mpls-tp-shared-ring-protection-00

From: cheng weiqiang <[email-masked]>
Date: Sun, 11 Nov 2012 12:15:09 +0800

Hi Gregory,

Thank you very much for your comments, and my answers are list in follows.

• SPME given new Ring Tunnel name
[Weiqiang] The Ring Tunnel here is a mechanism to optimize ring
operation and it can minimize OAM sessions, recovery elements, Labels
using, and management transactions which are described in RFC 5654.

• Implicitly jumps between single ring and interconnected rings scenario
[Weiqiang] This draft only provide the solution for the single ring
protection, and the interconnected rings scenario will be post in
separated file.

• Only Link OAM being considered, what makes steering more challenging
[Weiqiang] Current version we introduced the Section layer OAM for the
ring protection, it can give very quick fault detection and less OAM
sessions.

• No mention that Link or Node protection in wrapping has to be pre-determined
 [Weiqiang] the mechanism in the draft treats the Link fault and node
fault with the same way exactly. In order to make it more clear, we
present both the links fault and nodes fault examples seperatedly in
the draft.

• Coordination protocol – TBD
 [Weiqiang] it will be added in the new version.

• Hard to identify advantages of this approach when comparing with
solutions described in draft-weingarten-mpls-tp-ring-protection-06
protection of p2p bi-directional LSP.
[Weiqiang]I don't want to compare the two solutions directly because
we have clarified that draft-weingarten-mpls-tp-ring-protection-06 is
"to create an applicability statement on how to use linear protection
in ring topologies" in co-chairs conclusion
http://www.ietf.org/mail-archive/web/mpls/current/msg08807.html,  but
our draft is "topology-specific protection solutions" which co-chairs
mentioned in the same link are welcomed by WG.
I compared “draft-weingarten-mpls-tp-ring-protection-06” with linear
protection, and comments are in link
http://www.ietf.org/mail-archive/web/mpls/current/msg09014.html for
your reference.

B.R
Weiqiang Cheng

From: Gregory Mirsky [mailto:[email-masked]]
Sent: Friday, November 09, 2012 5:32 AM
To: [email-masked]; [email-masked];
[email-masked]; [email-masked]; [email-masked];
[email-masked]; [email-masked]; [email-masked]
Cc: [email-masked]
Subject: Comments on draft-cheng-mpls-tp-shared-ring-protection-00

Dear Authors, et al.,
below are my comments to your document I've mentioned at MPLS WG
meeting earlier:
• SPME given new Ring Tunnel name
• Implicitly jumps between single ring and interconnected rings scenario
• Implicitly considers p2p bidirectional corouted LSP even though more
generic p2p scenario stated
• Only Link OAM being considered, what makes steering more challenging
• No mention that Link or Node protection in wrapping has to be pre-determined
• Coordination protocol - TBD
• Hard to identify advantages of this approach when comparing with
solutions described in draft-weingarten-mpls-tp-ring-protection-06
protection of p2p bi-directional LSP.

Regards,
        Greg