UC520 call-forward drops 20 sec after offhook

[arellanolouie]

if someone call the sydney PSTN DID numbering block and gets forwarded one of the phone in

manila office, if the call forward noan is configured to a phone, the call will forwarded

back to sydney mobile number. 20 seconds after off-hook the connection drops.

[paolo bevilacqua]

Do you have ISDN? Suspect router is not acknowledging a connect from the switch. This is verified with "debug isdn q931 and term mon". Withou hypothesizing more, alse send same debug for a regualr outgoing call. Do not enable any other debug.