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

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

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.

> 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.

Cheers, Huub.

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