Subject: ldp mib object

From: "Santosh Gupta" <[email-masked]>
Date: Fri, 15 Oct 1999 14:54:25 +0530

Hello all,
    This is in reference to "draft-ietf-mpls-mib-01.txt". 
"MPLS LDP Session Table the OBJECT TYPE mplsLdpSessionKeepAliveHoldTimeRemaining" on the page no. 23 is asking for the time remaining for the timer to expire. I want to know what is the use of this object by the SNMP agent.

    The other doubt is:
On pg 18 under "The MPLS LDP Peer Table" there is an object "mplsLdpPeerID" . What does it stand for ? Is it for some indexing purpose among the peers of the LSR?
 
Santosh Gupta

---

From: Hans Sjoestrand <[email-masked]>
Date: Fri, 15 Oct 1999 18:10:30 +0200 (MET DST)

Dear Santosh Gupta,

Answers embedded below

> "MPLS LDP Session Table the OBJECT TYPE
> mplsLdpSessionKeepAliveHoldTimeRemaining" on the page no. 23 is asking
> for the time remaining for the timer to expire. I want to know what is
> the use of this object by the SNMP agent.

I don't understand if you are questioning the usefulness of this object
or asking for a clarification of its description. But the object is
showing the remaining time until the KeepAlive timer expires (and the
LDP session is terminated). Please see section 2.5.6. Maintaining LDP
Sessions in draft-ietf-mpls-ldp-06.txt

> "MPLS LDP Session Table the OBJECT TYPE
> mplsLdpSessionKeepAliveHoldTimeRemaining" on the page no. 23 is asking
> for the time remaining. I am using the system timer calls to implement
> the timers. How do I achieve the above in my implementation ? The
> system timer does not return how much time has elapsed since it was
> created.

I have little knowledge of your timer implementation but the usual way
to implement this is to save a timestamp when you reset the timer
(when you receive an LDP PDU) and then let the agent compare that with the
current time for the read operation. That gives yuo the elapsed time, 
simple subtract that from the configured keepalive hold timer
(mplsLdpEntityKeepAliveHoldTimer). 

> 
>     The other doubt is:
> On pg 18 under "The MPLS LDP Peer Table" there is an object
> "mplsLdpPeerID" . What does it stand for ? Is it for some indexing
> purpose among the peers of the LSR?
>  

It is part of the indexing but it is also unicly identifing the LDP ID of
the peer. See section 2.2.2. LDP Identifiers in
draft-ietf-mpls-ldp-06.txt

regards
/// Hans Sjöstrand