T42G - Unable to get sound when transfer a call to external number

[foxco]

Hi,
I'm using a T42G ( 29.80.0.130 )
I define a forward button when I'm off my desk to forward the incoming flow to my mobile.

This is working fine : my mobile ring

but there is no sound

If I call my mobile from my desk : no problem.

I'm behind a Yeastar MyPBX soho.

Do you have ideas ?
Thanks

[Karl_Yealink]

Both side can't here sound? Or only one side? Which side?
And this problem only occur when you forward the call to mobile? If you forward the call to another SIP phones?
And you dial the mobile directly from the same phone, everything goes well.

Can you help us to get the trace files two times, one time for forward scenario, another time for directly call scenario.
You can know the method via the FAQ: http://support.yealink.com/faq/faqInfo?id=311
You can send the files to me via email(karl@yealink.com), I will check then give you respond.
Note, please copy this post, so I can know the file for which problem