Most common reason this happens - clock slips on the PSTN gateway digital trunks.
Assuming you have some kind of T1/E1 gateway, do a show controller and check the stats - if you see clock slips then this could be the problem.
The reason why the faxes work VG224 ---> PSTN is the traffic in this direction does not experience slips, but the traffic PSTN ---> VG224 has slips in the bit stream, which cause errors in the data, the fax protocols detect these erorrs and retransmit, but the errors keep occuring and eventually the fax machine drops the call.
Assuming you have a T1 card in slot 0/0/0 of the PSTN gateway router, you need the following commands -
network-clock-participate t1 wic 0
network-clock-select 1 t1 0/0/0
this will recover the clock signal off the PRI on controller e1 0/0/0 and use it to drive the DSP's and the traffic in the TX direction, so there will be a common clock reference system wide and the slips should be cleared.
I'm not able to access my old voice mail messages all of a sudden. The recording says something like 'the message is currently not available'. This has never happened before in all the years I have been using this system. I have t...