chan_sip: Handle a request to negotiate T.38 after it is enabled.
Some T.38 implementations may send another re-invite after the initial
one which adds additional negotiation details (such as the max bitrate).
Currently this will fail when passthrough is being done in chan_sip as we
do nothing if T.38 is already active.
Other handlers of T.38 inside of Asterisk (such as res_fax) handle this
scenario so this change adds support for it to chan_sip. If a request
to negotiate is received while T.38 is already enabled a new re-INVITE is
sent and negotiation is done again.
projects / thirdparty / asterisk.git / commit
