Subject: RE: PIM-SMv2 functional clarification - join latency

From: Narayanan Vidya-CVN065 <[email-masked]>
Date: Tue, 24 Aug 1999 17:22:18 -0500

> Here is what they said in English:
> 
>  1) If the RP has lost (S,G) state (due to any number of 
> reasons including
>     operator clearing state), the RP has to wait until the next
>     (null) register to set up (S,G) state, and join again; (Dave)
> 

Yes, I agree with this in the event of no (S,G) state in the RP.

>  2) If the RP has not yet lost the (S,G) state, it should 
> trigger a join
>     to the source when the first member shows up. (Ravi)
> 

Here is where I am having a problem relating this to the RFC. The RFC only
seems to talk about (*,G) joins. Isn't it an (S,G) join that needs to go
from the RP to the source?

thanks,
Vidya

---

From: Liming Wei <[email-masked]>
Date: Tue, 24 Aug 1999 15:32:02 -0700 (PDT)

[Note, Bcc'ed idmr where members may not be interested in such
 details about PIM.]

> From: Narayanan Vidya-CVN065 <[email-masked]>
> 

When a (*,G) join is received and the arriving interaface is added to
the (*,G) outgoing interface list, the protocol specification requires
that the same interface is added to the (S,G) entry's outgoing interface
list as well.

The reason you heard the mentioning of (*,G) join, was because that
was the only thing the router connected to the new receiver knew. It
does it only knows G and the RP and how to send a (*,G) join. The RP,
if it has knowledge of (S,G), will know how to trigger (S,G) joins on
receipt of a (*,G) join.

-Liming