[e2e] A metric to evaluate RTT estimation techniques for layered (multi-rate) multicast protocols

[Osman Ghazali (FTM)]

Hi, 
I am referring to my previous email(How could I know a RTT estimation
technique is better than other other estimation techniques)

I am particularly interested in RTT estimation for layered multicast
protocols (LMPs), where most of the protocols employ TCP throughput
models to regulate their receiving rates. RTT estimation for layered
multicast communication, however, due to the feedback implosion problem
at the sender, is rather difficult than RTT estimation for unicast. 

I have got a number of RTT estimation techniques in my list, i.e. the
techniques proposed by Luby, Basu, Rhee, etc. However, currently my 
problem is how to know which technique is the most appropriate technique
for LMPs. Here, I prefer not to use the word accurate because I think
for layered multicast communication, the most accurate RTT estimation
is not necessary the most appropriate RTT estimation. There are other
factors have to be considered, such as feedback implosion, processing
overhead, etc.

A metric would greatly help me to compare and evaluate those techniques.
Alternatively I will evaluate the techniques based on the performance a LMP
(indirect evaluation). I mean, I will perform many runs of a LMP, where each
run will have the same setting and parameters but a different RTT estimation
technique. Then, I will see how the LMP performs in each run.

Finally, again, 
Is there any metric for RTT estimation techniques (for layered maulticast) ?
or 
Any suggestion of how to evaluate RTT estimation techniques (for layered 
multicast) ?

Thank you.

Osman