As I understand it you are not using X264 but are using a commercial H.264 stack and breaking the single encoded frame into several NAL (of less than 1.4k)  to fit into an RTP frame thereby making it compliant to connect to commercial H.323 endpoints. Since the commercial stack was sending successfully without the modification (Single NAL per RTP Frame)  then the only thing I can suggest it is how you are breaking up the single encoded frame. I think you will need to do some more debugging with your commercial H.264 stack and how you are encoding the single NAL to determine where the problem lies.
 
Simon

From: h323plus-bounces@lists.packetizer.com [mailto:h323plus-bounces@lists.packetizer.com] On Behalf Of ooi khai chin
Sent: Wednesday, 23 December 2009 4:42 PM
To: h323plus@lists.packetizer.com
Subject: [h323plus] H264 PLUGIN in H323plus

Hi All,
In my situation, I have set my marker to 1 when it is the last partial frame, And it able to display on the remote endpoint every frame I sent. The problem is it just delay around 5s for all frame picture.
Why? I already do some testing on my x264 encoder, it can encode frame with acceptable speed, So it wouldn't be encoder problem.

Thanks.