Subject: PIM-SM join/prune suppression timer question

From: Ravi Shekhar <[email-masked]>
Date: Fri, 16 Jul 1999 15:13:18 -0400

From the descriptions in the rfc2362, it appears to me that 
the Join/Prune suppression timer in PIM-SM is supposed to 
be used to suppress only joins (but not prunes).
Is that correct? 

If so, I think the text in section 3.8.1 should be clarified 
a little bit:

>3.8.1 Timers related to tree maintenance
...
>     *    [Join/Prune-Suppression-Timer (kept per route entry)] A
>          route entry's (optional) Join/Prune-Suppression-Timer may be
>          used to suppress duplicate joins from multiple downstream
...
>                                                    While the timer
>          is running, Join/Prune messages for the entry are not sent.
...

The last two lines seem to suggest that "prunes" should also be 
suppressed.
Consider the case where there is an <S, G> entry with different 
IIFs for SPT and shared tree. It should not suppress its prunes 
towards RP(on the shared tree) even if the Join/Prune suppression 
timer is running to suppress joins towards S(on SPT).

- Ravi Shekhar.

---

From: Ravi <[email-masked]>
Date: Mon, 19 Jul 1999 10:40:14 -0700

Ravi Shekhar writes:

| The last two lines seem to suggest that "prunes" should also be 
| suppressed.
| Consider the case where there is an <S, G> entry with different 
| IIFs for SPT and shared tree. It should not suppress its prunes 
| towards RP(on the shared tree) even if the Join/Prune suppression 
| timer is running to suppress joins towards S(on SPT).

Isn't the entry towards the RP a <*, G> entry? The join/suppression
timers are per route entry. If you have a join/suppression timer
on the <S, G> entry, then it should not effect sending prunes on the
<*, G> entry.

Ravi