Using a packet sniffer I have captured some requests & Response
packets related to the Oracle D/B server. I want to decode them in
order to understand the D/B network activity and calculate the server
response times. I have tried using the trcasst tool provided by Oracle
for the purpose, but with little help so far. Also, I have heard that
Oracle has obsoleted the tool.

I would like have the specifications of Oracle's TNS, TTC and SQLNet
protocols for all existing versions of Oracle, esp Oracle 8i and
Oracle 9i.When I say specifications, it means an explanation of the
meaning/purpose of each and every byte of each and every message used
by the Oracle client and Oracle server to communicate over the
network.

It sounds like you are trying to invent a wheel that is 
already "round".. Check out http://www.sqlpower.com/sqlmonitor.html
They make a sql performance monitor that captures/parses and tracks
the sqlnet packets.

Hi Nambiar,
I also need the same thing for my summer training project, have u got
the docs of (TNS + SqlNet) message structure? If yes, can you please
reply?

Thanks.
--pradip

I would think you are seeking information thats proprietary, plus
Oracle will also be encrypting the packets for security purposes.