[pjsip] Handling ip change during call

[John Gathm]

Hello

I'm trying to handle ip change during call on iOS, between cellular data
and wifi.

I'm following the wiki page.
https://trac.pjsip.org/repos/wiki/IPAddressChange

Using Apple's reachability API, on connection change,
I'm calling pjsua_call_reinvite() with PJSUA CALL REINIT_MEDIA and
PJSUA_CALL_UPDATE_CONTACT, but just doing this call and nothing else.

I'm surprised... this works. I can still have audio both ways after I shut
down wifi to switch to cellular or when I switch back to wifi.
However, I did not do anything regarding transport (I'm using TCP) or
account registration.

Is the wiki part about the transport re-creation still relevant ? I wonder
if I'm hitting the following feature:

"PJSUA-LIB has the capability to detect the (SIP) IP address change based
on the response of REGISTER request and automatically update the
registration with the correct IP if it detects that the IP/port seen by the
server is different than the address specified in the Contact URI. This
feature is enabled by default, via the pjsua_acc_config.allow_contact_rewrite
setting."

triggered during the call. (I'm not needing to handle IP change outside of
a call, using Pushkit to signal incoming calls)

best regards

J.G