Re: [Mpls-interop] MPLS-TP OAM requirements - Lock and notification of lock

[Martin Vigoureux <[e-mail]>]

Huub,

please see inline,

regards,
-m

Huub van Helvoort a écrit :
> Bonsoir Martin,
> 
> You wrote:
> 
>> here are my thoughts on this:
>>
>> As far as I understand, strictly speaking the Lock function
>> does not make sense on a unidir LSP. Indeed locking is performed
>> at the source point and so there is no need to send any message
>> to perform that Lock. (the potentially needed message is to inform
>> the end-point(s) of the status but that is lock notification.
>> I'll come back to this).
> 
> What should happen if the CP and MP are separated, i.e the
> ingress point and egress poinr belong to different SP domains?

[mvx] please se my other e-mail.

> 
>> Therefore Lock is only needed on a bidir entity and what is exactly
>> needed is the capability to request the other end point to admin lock
>> its direction.
> 
> What do you mean by "its direction", the direction from "the
> other end point" back to the "source point"?

[mvx] in case of bidir, both nodes are sources points.
What I mean is that a node (A) should have the means to ask its
associated end point (Z) to Lock the direction of the LSP that
goes from Z to A.

> 
>> Coming back to the notification, I believe the following requirement
>> is needed:
>>    The MPLS-TP OAM toolset MUST provide a functionality to enable an
>>    End Point of a PW, LSP or Section to inform the End Point(s) of that
>>    LSP, PW, or Section that the PW, LSP or Section has been
>>    administratively shutdown at this End Point.
>> But it is conditionally needed. This function is *only* needed if
>> locking is achieved via Lock, otherwise if it is achieved via NMS
>> commands
> 
> This requires that both end points can be reached via the MP.

[mvx] indeed but that does not contradict the above.

> 
>> we (I hope) can safely assume that:
>> for undir LSP there will be commands at both ends, one saying lock, 
>> the other saying you are notified of other end locking.
>> for bidir LSP there will be commands at both ends, both saying lock 
>> and you are notified of other end locking.
>>
>> The MUST is needed because the egress must be aware of the Lock because
>> we expect him to then inform client MEPs that are "downstream". (see
>> question at the end of this e-mail).
>>
>> The small problem I have is that this function is a notification
>> one but really tightly linked to the Lock. In other words, I do
>> not know where this reqs better fits (especially wrt to the conditional
>> issue): in Lock or in Lock Notification?
>> Opinions are welcomed.