ZyXEL Communications omni series Data over Speech Channel, Best-effort call answering non-data

Data over Speech Channel

If you are expecting ISDN data calls through the Speech (Voice) channel, you need to setup MSN for it. For non-data models if no MSN entries are found in MSN ISDN data lists, all Speech (Voice) calls will be sent to either Phone 1 or Phone 2. Which entry to use would depend on the type of data call that you are expecting. If you only expect PPP calls, you should enter the number that the remote user will use to dial in entry #3 (AT&ZI3=xxx) or entry #5 (A&ZI5=xxx). Once this is set, the TA will attempt to use PPP protocol to handshake with the remote site whenever a caller dials into this number.

Best-effort call answering (non-data)

If some numbers have been set using the &ZIn command (this can be seen by issuing the AT&ZI? command) and they are not matched with the address of the incoming call, the TA will, by default, ignore the call as it may be intended for other devices that share the same S/T interface (S0 bus) with the TA.

If you want the TA to answer inbound calls using all possible protocols, you can set the best-effort call answering bit as follows:

Command	Function
ATS119.3=0	Answer call only when number matched. (default)
ATS119.3=1	Best effort call answering.

Ambiguity resolution switch for voice calls (omni.net)

For a Speech or voice-band-data call, if the &ZI number assignment can tell which of the analog adapters is being addressed, then the call will be delivered to the proper destination. But sometimes, ambiguity of address matching may exist. This may happen if the &ZIn numbers of the various protocols are either unassigned or not matched. In this case, users may wish to set answering priority to an analog port. The AT&Ln command sets the address ambiguity resolution flag as follows:

ISDN Communication Basics 33