AMR: Signal usage of octet-aligned or bandwith-efficient mode to MSC

MGCP/SDP provides fmtp parameters in order to signal which of the two
available AMR framing modes (octet-aligned or bandwith-efficient) should
be used on the link between BSS and core network. osmo-bsc currently
does not set up this mode which means that the RTP packets from the BTS
are forwared without inspection/modification, which may lead to
malfunction when a BTS is using a framing mode that is not supported by
the other end.

- Add VTY option to setup the framing mode
- Generate related fmtp parameters in SDP

Depends: osmo-mgw I622c01874b25f5049d4f59eb8157e0ea3cbe16ba
Change-Id: If6d40b2407b87aad2227ea7f15533ef01a3771b3
Related OS#3807
3 files changed