Subject: Questions on LDP MIB v9

From: Neil Jerram <[email-masked]>
Date: Wed, 30 Oct 2002 15:32:25 -0000

The latest LDP MIB draft looks generally good, but I see three problems with
the new mplsLdpLspTable, which could be genuine, or could indicate
misunderstanding on my part -- so I would appreciate your thoughts on them.
I also have one question.
 
1. It isn't possible to represent an egress or transit LSP (A) at the same
time as an ingress LSP (B), if LSP A's incoming (interface, label) are the
same as LSP B's outgoing (interface, label), because the index in both cases
is the same: (i1, l1).  The old XCMapTable could represent both at the same
time, using indices (i1, l1, 0, 0) or (i1, l1, i2, l2) for LSP A and (0, 0,
i1, l1) for LSP B.
 
2. There is no mplsLdpLspType value to indicate a liberally retained label.
 
3. In the description mplsLdpLspType, your uses of "ingress" and "egress"
(as verbs describing the LSP's relationship to the LSR) are exactly opposite
to the conventional usage (which describes a data packet's relationship to
an LSP).  This could be rather confusing!
 
4. Do you expect implicit and explicit null labels to appear in this table,
and, if so, how?  The point is that implicit and explicit null labels can be
distributed multiple times for different FECs in the same session, and it
isn't clear in this case how the MIB indexing will work.
 
Best regards,
    Neil
 
Neil Jerram
Network Protocols Group
Data Connection Ltd.
www.dataconnection.com <http://www.dataconnection.com>