We are using grandstream phones with a UCM6510 PBX and found that after firmware upgrade to the newest firmware (phone and PBX) we cannot use MPK previously defined as speed dial to make unconditional call forward (*72 code) to a ring group or to a queue or to a IVR.
Model GXP1630: From version 184.108.40.206 to 220.127.116.11
Model GXP2170: Version 18.104.22.168 --> Version 22.214.171.124
UCM6510: firmware 126.96.36.199 --> 188.8.131.52
P.S. We first updated the phones when the error appeared. So we updated the PBX but it made no difference.
P.P.S. The unconditional call forward does work with the new firmware of UCM6510 and the previous versions of the phones firmwares, so it should be something wrong with the phone configuration (a new option that blocks it… ) or a bug in the new phone firmware.
Any help will be appreciated!
Thanks in advance