In our branch offices we have H323 gateways configured. They have got PVDM2-48 installed. They are registered with the callmanager to provide hardware conferencing. In our headoffice we also have a transcoder. My question is if we have a transcoder then why the routers at branch offices need to have PVDM registered with call manager to provide conferencing.
I assume this is because branch offices IP Phones use remote resources for conferencing.
Instead of coming to the HQ using WAN BW.
That is for the conference.
Regarding your question for transcoding...
XCODE is for convert different codec stream into another codec.
CONF...for joining streams...