RFC 7742 Section 6.2 mentions a number of H.264/AVC capabilities including:
max-mbps, max-smbps, max-fs, max-cpb, max-dpb, and max-br:
These parameters allow the implementation to specify that they can
support certain features of H.264 at higher rates and values than
those signaled by their level (set with profile-level-id).
Implementations MAY include these parameters in their SDP, but
they SHOULD interpret them when receiving them, allowing them to
send the highest quality of video possible.
However, while Section 220.127.116.11 includes support for these in capabilities, Section 18.104.22.168 does not include them in settings.
As a result, if a receiver were to signal a value of maxFs, there would be no way to set a maxFs value on the sender.
Add H.264/AVC sender settings
Fix for Issue #641