Re: [Mpls-interop] MPLS-TP OAM requirements - AIS/LockNotif - Can MIPs send "usolicited" OAM messages ?

[Huub van Helvoort <[e-mail]>]

Hi Martin,

You responded:

> please see in-line.

me too [hvh]

> Huub van Helvoort a écrit :
>> Bonsoir Martin,
>>
>> You wrote:
>>
>>> as part of the discussion on AIS/Lock Notification,
>>> the server layer MEPs, detecting a fault/lock condition, should
>>> inform (the MEPs of) the client layers relying on that
>>> server layer and which are affected by the condition.
>>>
>>> However as I understand it is not the MEP (sMEP) of the
>>> server layer that sends a notification to the client layers
>>> MEPs (cMEP) but the MIP (cMIP) of the client layer which
>>> is hosted on the same node than the MEP (sMEP).
>>> See the figure below (where the double dashed line is
>>> an LSP, and the ~ line represents an LSP nested in the
>>> other LSP.
>>>
>>> +------+      +------+      +------+      +------+
>>> |      |------|      |------| cMIP |~~~~~~| cMEP |
>>> |      |      |      |      |  ^   |      |      |
>>> |      |      |      |      |  |   |      |      |
>>> |      |      |      |      |  |   |      |      |
>>> |      |======|      |======| sMEP |      |      |
>>> +------+      +------+      +------+      +------+
>>
>> I modified the figure to align with what you wrote.
> 
> [mvx] thx. In fact the double dashed line was already there
>       but with quite some spacing between the top and bottom.

[hvh] OK, tI had the impression that the upper line indicated
the client path/trail, and the lower the server path/trail

>>> Therefore can MIPs send OAM messages without having priorly received one
>>> or did I miss something?
>>
>> No, a MIP can only respond to messages it receives from a MEP
>> that has the same MEG level, i.e. exists in the same path.
>>
>> In your figure the cMIP ignores messages sent by sMEP.
> 
> but then, how does a Lock condition of the lower LSP
> is notified to cMEP?

This is a consequent action performed in the normal
adaptation function between server and client layer.

Best reagrds, Huub.

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