Re: Non-Querier behaviour on receiving grp specific orgrp-and-src specific queries

Hi Bharat, please see inline :

-----Original Message-----
From: Bharat Joshi [mailto:[email protected]] 
Sent: Friday, May 23, 2008 2:07 PM
To: Suvendu Mozumdar
Cc: [email protected]
Subject: Re: [magma] Non-Querier behaviour on receiving grp specific
orgrp-and-src specific queries

Suvendu,

> 
>      I have an issue for which the RFC 3376 does not suggest anything.
> Lets say in a Lan there are two igmpv3 routers and one igmpv3 host
> present. Lets say Q1 is querier and Q2 is non-querier. Now Host1 sends
> include s1 for grp G1. Both Q1 and Q2 will have an entry in their
> respective database. Now Host1 sends a report block s1 for grp G1. Q1
> on receipt of this block report will start LMQT timer, set the source
> timer of s1 to LMQT and start sending group and source specific
> queries for G1/s1. After LMQT expires Q1 will delete the entry of
> G1/s1 from its database. Now what will be the non-querier's behaviour.
> Will it also start LMQT, 

Please look at section 6.6.1. When a non-querier receives a query, it
reduces its corresponding timer to LMQT which can be derived from
max-response code.
Suvendu : As per section 8.10, LMQT = LMQC*LMQI, I agree that LMQI is
the max-response code in the specific query, but LMQC is configurable
and MAY differ in querier and non-querier. That's where my doubt arises.

> in that case Querier's LMQT and non-querier's LMQT (which is
> LMQC*LMQI) may differ based on different LMQC values. Non-querier
> comes to know about the querier's LMQI from the Max Response Code in
> the specific query pkt but what about querier's LMQC, non-querier has
> no way to know about the querier's LMQI.

Non-querier does not need to know LMQC as it is not required. LMQC is
required for a querier to generate number of queries.
Suvendu : Not only that, LMQC is used in calculating LMQT, pl refer
section 8.10.

Also most of the times, it is expected that all routers are configured
with same values but things should still work if they are not.

Hope this helps.

Thanks,
Bharat


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