[xiph-rtp] header caching and chaining

[Ramón García]

There is a strong problem with supporting chaining: it breaks encapsulation. 


Single stream                   |  Several Streams
--------------------------------------------------------------------
Vorbis streams                 | OGG Container
Different RTP sesssions    | RTSP 


Aaraon, why are you saying that not supporting chaining would imply
not serving some OGG files. Don't RealMedia, Quicktime and other
formats use different RTP sessions for each stream contained?

On the other hand, there is an important argument in favour of
supporing chaining: allowing dynamic changes as a response to changes
in the network conditions. So I think that limited support for this
case would be justified.

Aaron, how does RealAudio handle changes in network bandwidth?
Different RTP sessions, or just one?