Hi, Take a look on the H323CodecExtendedVideoCapability::OnSendingPDU function. I have had some issues with Extended capabilities and have fixed the issue only after change the view order - we need to look the .table first and only if it empty - work with extCapabilities. For current implementation we always work the extCapabilities only because it always has GetSize()>0 (otherwise we return FALSE at the beginning of this function). PBoolean H323CodecExtendedVideoCapability::OnSendingPDU(H245_VideoCapability & pdu, CommandType ctype) const  {      if (extCapabilities.GetSize() == 0)         return FALSE;    // bla-bla-bla          if (extCapabilities.GetSize() > 0) {       caps.SetSize(extCapabilities.GetSize());       for (PINDEX i=0; i< extCapabilities.GetSize(); i++) {          H245_VideoCapability vidcap;          ((H323VideoCapability &)extCapabilities[i]).OnSendingPDU(vidcap,ctype);          caps[i] = vidcap;       }     } else {       caps.SetSize(table.GetSize());       for (PINDEX i=0; i< table.GetSize(); i++) {          H245_VideoCapability vidcap;         ((H323VideoCapability &)table[i]).OnSendingPDU(vidcap,ctype);         caps[i] = vidcap;       }     }   return TRUE; }

Thanks -- Iurii Gordiienko