A non-standard codec

Dear sirs,

In the document

RTP Profile for Audio and Video Conferences with Minimal Control

There are description for several codecs, among them, GSM. But in H323 Version1/ V245 Version 2, there is no way to choose this codec.

¿Is there any way to work withs RTP "standard" codecs but H323-NON-standard codecs.

Thanks a lot,

Juan C Uribe G