We currently are experiencing some problems with the unattended transfer ability of the HT-488 from Grandstream. It is as follow:

* Incoming call on phone powered by a HT-488
* Press the Flash button on the phone to transfer the call to party X
* Party X does not answer the phone
* Pressing flash button again to regain call
* No call whatsoever, looks like it just did an Blind Transfer

Resolving the issue has got me a little closer but not entirely. When using an Answer() in Asterisk for the phone where we want to transfer to we can get the call back, however it looks like the transfer is still in the background. When hanging up the phone we want to transfer FROM it will ring a little later with a call from the party we are transferring TO. Little step closer to what we want, but obvious this also sucks.

I'll keep some updates here about the HT-488 and my issues.

Seems more people are having troubles with the handytones and flash transfer:

• [Asterisk-Users] Re: GS HandyTone-286 Transfer Problem, can anyone confirm?

Upgrading the HT-286 to firmware version 1.7.11 (available at http://www.grandstream.com/BETATEST/BT100_HT286_HT486/) does resolve the issue partly as the taking back of the call works correctly, however the next problem I encounter is that I only see audio one-way.