Grandstream Transfers in Asterisk 1.6


I’m hoping someone here may have an idea why transfers are no longer working on my asterisk server.
I recently upgraded from 1.4.25 to and I can no longer perform unattended or attended transfers from any of the phones (Grandstream GXP2020). Pressing the transfer button bring up the transfer menu, but choosing a line or dialling an extension just drops you back in the original call again.

I never had to add any transfer logic to the dialplan to get this working originally, it seemed to be handled by the phones themselves. I’m using the exact same config as the old server so they may be a setting that needs to change, or be added/removed but I’ve no idea where to look.

Here’s my sip config for one of the phones and the dial command I’m using for outbound calls:

[231] context=group1 type=friend username=231 secret=... host=dynamic nat=yes callerid="Users Name" <231> mailbox=231 call-limit=6 busy-level=1 allowtransfer=yes allowoverlap=yes callgroup=1 pickupgroup=1 qualify=yes disallow=all allow=gsm,ulaw,alaw,g723 amaflags=billing


I’d appreciate it if anyone has any ideas


After about 3 hours of searching the net and trying different settings I finally managed to get this working again so I’m replying here in case anyone has the same problem.

It appears that ‘allowtransfer=yes’ must work differently than in 1.4. I have had to add allowtransfer=yes to the general section of sip.conf, instead of just on the user entry itself, which has got my phones working as they used to.