SIP Issue with IOS Client (Android is working)

[the_boss_me]

I have issues with SIP telephonie with IOS Devices. Android devices are working fine.
When dialing with IOS via my SIP (ni issue with forwarder, while Android device is working properly)

voice is not hearable while using the IOS device.

Regards Bea

[AndrewZ]

Ask your SIP provider first.

[the_boss_me]

SIP Provider = German Telekom.
There is no issue with Android Mobile devices.
I have tried with iPad and iPhone.

So why working with android and not with iOS devices ?

[AndrewZ]

Ask your SIP provider. I do not see your SIP and RTP traffic and cannot give you the reason, but they do see it and can analyse it.