Subject: Keep Alive Timer

From: [email-masked]
Date: Tue, 15 May 2001 15:51:38 +0200

I have a small question concerning the KeepAlive Timer :

Consider that multicast trafic for group G comes through the SPT (from one
source to a member). If the source stop sending trafic during 210 second
(Keep_Alive Period), the (S,G) states are deleted in all the routers between S
and the member. So if the source starts sending data again, it must pass through
the RP ?

I hope i am clear enough !!

Thanks

ALCATEL SPACE INDUSTRIES
DTS/DAT/E  --  Stagiaire
Tel : 33 (0) 5 34 35 37 52  /  Fax : 33 (0) 5 34 35 61 69
Porte : F-2070  /  E-Mail : [email-masked]

---

From: Isidor Kouvelas <[email-masked]>
Date: Tue, 15 May 2001 09:58:39 -0700

>and the member. So if the source starts sending data again, it must pass throu

Correct. When the last hop router tears down the SPT by sending the
(S,G) Prune towards the source, it also sends an (S,G,rpt) Join towards
the RP to tear down the prune state for the source on the shared tree.
So if the source starts sending again the data will reach the receiver
and the last hop router caninitiate the SPT switch again.

thanks
I