hi Simon
 As you suggested I have added H323_H224Capability(). The brief code is

H323_H224Capability *p = new H323_H224Capability();
capabilities.Add(p);
in a class derived from H323EndPoint.

The watch window here doesnot show much.

But exe crashes in BOOL H323_H224Channel::Start()
at
h224Handler->StartTransmit();
I think it is not getting pointer right

Can you guide me from there.

alam.