Re: [mpls] MPLS ring protection reconsidered ??

[Kireeti Kompella <[e-mail]>]

Hi Loa,

Thanks for your mail!

I’m all for revisiting the question.  I was going to ask for WG adoption of RMR.

If the draft-cheng authors ask the same, I have no objection.  However, I think there are quite a few differences between the two drafts, and don’t think that merging them is the technically best solution.

Kireeti.

> On Mar 16, 2015, at 15:23 , Loa Andersson <[e-mail]> wrote:
> 
> 
> Folks,
> 
> (taking my chair hat off for a while, i.e. this should not be
> read as a chair directive, just a bit of mumbling that comes out
> thinking about how to progress documents.)
> 
> As far back s the 73rd IETF in Minneapolis John and Adrian made
> a report on "Requirements for Ring Protectionin MPLS-TP". The
> conclusions were that we could do topology specific protection
> solutions if the benefits are big enough.
> 
> Such solutions need to meet the same requirements as linear
> protection and it has to be show that it can't be done by linear
> protection only.
> 
> At that time we did not see that there were things that would not
> be as readily done by the linear protection being specified at that
> time.
> 
> Today we have to drafts that address ring topologies, one draft-kompella-mpls-rmr addresses Resilient MPLS Rings in an MPLS-TE
> environment. The other draft-cheng-mpls-tp-shared-ring-protection
> addresses protection in an MPLS-TP environment.
> 
> Both recognizes that ring topologies are very common and that very
> efficient mechanism for keeping traffic flowing in case of failures
> are possible to design. Sometime far better than what is the case if
> the actual ring topologies are view as a linear topology,
> 
> The first document (draft-kompella- ) looks primarily on the operations
> within a single ring and how fast and simple mechanisms for protection
> can be deployed. A ring topology is a very common deployment scenario.
> While, the draft-kompella from a solutions point is somewhat orthogonal
> to draft-cheng, it does also discuss the dynamic control plane for mpls
> ring, including auto-discovery and signaling. It seems that there are
> opportunities for co-operation between the two drafts in this area.
> 
> The other (draft-cheng- ) looks at what is called MPLS shared ring, i.e.
> a rather high number can shared the same path around the ring, and all
> traffic can be protected by a single operation.
> Another aspect of the shared tunnel is that if part of the ring
> (typically 2 nodes and one link) are part of more than one ring. It
> becomes possible to protect against more than one failure.
> 
> Maybe it is time to revisit the question and see if we want to adopt
> working group documents for the two scenarios outlined above.
> 
> /Loa
> -- 
> 
> 
> Loa Andersson                        email: [e-mail]
> Senior MPLS Expert                          [e-mail]
> Huawei Technologies (consultant)     phone: [phone]