[Linphone-developers] issues with mid-call handover on App Store Linphone versions - iPhone 8 / iOS 13.1.3

[German Cancio]

Dear All,

I am testing Linphone (both the current Apple App Store version: 4.2.1, SDK 4.3.1-pre.12+516dacf as well as the TestFlight version: 4.2.1, SDK 4.3.1-pre.6+0f4e35e) mid-call handover on iOS 13.1.3 (using an iPhone 8) … and it does not seem to work!

It is easy to reproduce on two scenarios:

a) Start call on Wifi, continue on mobile network:

1. start a call on Wifi

2. disable Wifi, continuing call on mobile network (LTE/3G)

and

b) Start call on mobile network, continue on Wifi:

1. start a call on mobile network (LTE, 3G)

2. enable Wifi, continuing call on Wifi

Both scenarios fail on iOS 13.1.3 + iPhone 8, while they work correctly on an iPhone 5S running iOS 12.4.4.

I have examined the linphone logs and on iOS 13.1.3 / iPhone 8, there is no attempt to do a new INVITE and to establish new SDP parameters. 

On the iPhone 5, the network detection works. See the corresponding logs:

a) going to Wifi to LTE:

2020-01-25 18:30:35:298 [liblinphone] MESSAGE New Wifi SSID detected: [none]

2020-01-25 18:30:35:299 [liblinphone] MESSAGE Updated HTTP proxy settings: no proxy

2020-01-25 18:30:35:299 [liblinphone] MESSAGE Global network status changed: reachable: [1].

2020-01-25 18:30:35:299 [liblinphone] MESSAGE SIP network reachability state is now [DOWN]

followed by 

2020-01-25 18:30:35:305 [liblinphone] MESSAGE Media network reachability state is now [DOWN]

2020-01-25 18:30:35:305 [liblinphone] MESSAGE SIP network reachability state is now [UP]

2020-01-25 18:30:35:306 [liblinphone] MESSAGE Media network reachability state is now [UP]

2020-01-25 18:30:35:306 [liblinphone] MESSAGE Starting stun server resolution [stun.linphone.org]

b) Going from LTE to Wifi:

2020-01-25 18:30:23:604 [liblinphone] MESSAGE New Wifi SSID detected: MYWIFINAME

2020-01-25 18:30:23:604 [liblinphone] MESSAGE Updated HTTP proxy settings: no proxy

2020-01-25 18:30:23:605 [liblinphone] MESSAGE Global network status changed: reachable: [1].

2020-01-25 18:30:23:605 [liblinphone] MESSAGE SIP network reachability state is now [DOWN]

followed by 

2020-01-25 18:30:23:643 [liblinphone] MESSAGE Media network reachability state is now [DOWN]

2020-01-25 18:30:23:643 [liblinphone] MESSAGE SIP network reachability state is now [UP]

2020-01-25 18:30:23:643 [liblinphone] MESSAGE Media network reachability state is now [UP]

2020-01-25 18:30:23:644 [liblinphone] MESSAGE Starting stun server resolution [stun.linphone.org]

All this is missing on the iPhone8: The SSID status change seems not to be detected on iOS 13.1.3 / iPhone 8.

I have observed this with our own PBX as well as using linphone.org accounts / servers.

Any hints? Anybody else having observed this? Any comments from the developers?

Many thanks,

Germán