Subject: [mpls-tp] Query regarding MIP creation in a MEG

From: venkatesan mahalingam <[email-masked]>
Date: Fri, 30 Jul 2010 15:38:48 +0530

Hi,
As per *draft-ietf-mpls-tp-identifiers-02 draft, section 7**.3**.  MIP_IDs*
   At a cross connect point, in order to automatically generate MIP_IDs
   for MPLS-TP, we simply use the IF_IDs of the two interfaces which are
   cross connected via the label bindings of the MPLS-TP LSP.  If only
   one MIP is configured, then the MIP_ID is formed using the Node_ID
   and an IF_Num of 0.  In some contexts, such as LSP Ping[13], the
   Node_ID alone may be used as the MIP_ID.
and
*draft-ietf-mpls-tp-oam-framework-07 draft section 3.4. MEG Intermediate
Points (MIPs)*
   A MEG Intermediate Point (MIP) is a function located at a point
   between the MEPs of a MEG for a PW, LSP or SPME.

   Once a MEG is configured, the operator can enable/disable the
   MIPs on the nodes within the MEG. All the intermediate nodes and
   possibly the end nodes host MIP(s).

<VM> What I understand from the TP identifiers draft is that, one MIP is
created in a node for all the MEGs.
But, OAM draft states that MIP is created within a MEG in a node.

If MIP is created within the MEG, how to uniquely identify a MIP with help
of IF_ID (Node_ID::IF_Num)?

*P2P transport LSP:*
                                                    ME
MEG ----------- Local MEP    --------------------------- Remote MEP

*P2MP transport LSP:*
                                                         ME1
MEG ----------- Local MEP (root MEP) ----------------- Remote MEP (leaf
MEP1)
                          |               ME2
                          ------------------------------------------ Remote
MEP (leaf MEP2)

So, MEPs are only associated with MEG and ME is just a logical entity to
represent a transport path that is being monitored with the help of two
MEPs.
Is this understanding correct?

-- 
Best Regards,
Venkatesan Mahalingam.