[asterisk-dev] AST_FRAME_DIGITAL

[Matthew Fredrickson]

Klaus Darilion wrote:
> Thus, to summarize:
> 
> I see two options for adding digital/3G video types to Asterisk:
> 
> 1. AST_FORMAT_H223. This will only be used if the incoming call is 
> digital AND signals H.223&H.245.
> 
> + with this option it is for sure that the digital call is a 3G video call
> - there is no standardized way to forward this to other Asterisk server
> - does not help us handling other non-3G-video calls
> 
> 2. AST_FORMAT_CLEARMODE. This will be used for any incoming digital 
> call. Thus, from the frametype it is not deriveable which application is 
> inside the CLEARMODE.
> 
> + by adding CLEARMODE to rtp.c we have a standard conform way to forward 
> digital calls to other Asterisk servers
> + more generic and flexible
> - requires a little bit more dialplan logic to detect 3G video calls
> 
> Thus, is there a chance to get AST_FORMAT_CLEARMODE into Asterisk (which 
> I would prefer instead of AST_FORMAT_H223)?

Although it probably sounds very attractive, functionally this is the 
same thing as the proposal to use AST_FRAME_DIGITAL as an opaque 
container.  So if you were using AST_FORMAT_CLEARMODE, you are not going 
to be able to tell the other end of the IAX connection about what it is 
terminating, so if it needs to bridge the call to a non ISDN endpoint 
(such as a videophone) this will not be possible.  AST_FORMAT_CLEARMODE 
is not the answer, at least for the H.223 and H.245 data problem that we 
are discussing.

-- 
Matthew Fredrickson
Software/Firmware Engineer
Digium, Inc.