Two Questions on PIM

[Shuqian Yan <syan@jupiter.nal.utoronto.ca>]

Hi, ns-users

I have two questions here, hope any you of you can help to answer.

(1) If I have the following simple topology with 7 nodes, whereas node 0 is the 
source sending to a particular group, and also a receiver for the group, 
node2,9,3 and 1 are group members, node 8 is just an on-tree node that is not a 
group member yet.

                      0
                      |
                      |     
                  9---4---2
                  |       |
                  |       |
                  8       3
                  |
                  |
                  1
In unicasting, the total # of hops traveled to reach all group members will be 
2hops(to reach node9)+2hops(to reach node 2)+4hops(to reach node1)+3hops(to 
reach node3)=11 hops.

In PIM routing, the total # of hops for a packet to reach to all group members 
is only 6 hops, as the copies of packet got fowarded along the shared tree. 

My question is if I am using PIM, how can I track the # of hops that a packet 
travelled to reach all the group members? I could not simply subtract the ttl 
values when a receiver received a packet, because that will miscount the values.

(2) Is there any way to monitor the # of flows per link in the topology? To use 
the flow monitor? how?

Any ideas?

Tks,

shuqian YAN