Re: fax over IP T38 using protocol between cisco and fax applica
Below are the detailed results of tests conducted configuring the CISCO gateway as the fax transmitter with the above suggested configurations.
1.When CISCO gateway originated the call:
With fast_start alone enabled on our H.323Stack also, the voice call is established during the H.225 "CONNECT" message. In our H.245 "TERMINALCAPABILITYSET", one of the codecs we support is T.38 fax for UDP protocol with a maxbitrate of 144. Yet, after the TERMINALCAPABILITYSET (TCS), MASTERSLAVEDETERMINATION (MSD), TERMINALCAPABILITYSETACK (TCSACK), and MASTERSLAVEDETERMINATIONACK (MSDACK) messages exchange between both the endpoints, no other messages are either sent to or received from either ends while, CISCO gateway is supposed to send a H.245 REQUESTMODE message after detecting the faxtone hence, allowing us to switch from voice to fax mode. After sometime, CISCO gateway sends a RELEASECOMPLETE message without specifying any reason in the ReleaseCompleteReason field.
With Fast_Start and Tunneling enabled, the voice call is established during the H.225 "CONNECT" message. Then, the TCS, MSD, TCSACK and MSDACK messages are also exchanged in the H.225 "FACILITY" massage as per tunnelling requirements. In our TCS, we send T38FAX supporting UDP protocol with a maxbitrate of 144 as one of our capabilities. But still, the REQUESTMODE message is not sent from the CISCO gateway in order to switch from voice to fax mode. Similar to the above case, a RELEASECOMPLETE mesage is sent and the call ends abruptly.
2.When ENCORE H.323 STACK originates the call:
When we send a normal H.225 SET_UP message with all the mandatory fields set, we receive a RELEASECOMPLETE message from the CISCO gateway without the reason field set. When we send a H.225 SET_UP message with fast_start enabled and the one of the FASTSTART elements' OPENLOGICALCHANNEL codec's being T.38FAX supporting UDP protocol with a maxbitrate of 144, the CISCO gateway sends a RELEASECOMPLETE message without specifying the reason.
When a tunnelling enabled H.225 SET_UP message is sent from H.323 stack, similar to the above cases, a RELEASECOMPLETE message is sent from the CISCO gateway.
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...