DIVA T/A ISDN Modem User’s Guide ◆ Page 41
The DIVA Terminal Adapters Program for Windows95/98/NT
Phone Port Tabs
These tabs only applies if your DIVAT/A is equipped with analog device ports.
Certain DIVAT/A models provide two phone ports for connectin g analog devices such as
telephones, fax machines, and modems. Voice calls originating from analog devices are
carried over ISDN.
Since there are two B-channels, the DIVAT/A supports up to two concurrent phone line
connections, depending on whether there is a data call in place or not. The following method
applies whenever simultaneous data and voice calls are required:
Data Only. Whenever possible, you should use Multilink PPP since it provides maximum
throughput with the remote device. You can also configure PPP, V.120, and V.110 protocols. In
these cases, one B channel is used for data and the other is used for voice.
Data and Voice. When there is only data, MultilinkPPP is used as explained above. However,
one phone line can still be used if Dynamic Bandwidth Allocation (DBA) is enabled.
For example, if one of your telephones rings while a MultilinkPPP data connection is in
progress, one of the B-channels is automatically dropped, reducing th e data connection from
128 kbps to 64 kbps. The voice call is then connected. When the voice call ends, the
connection on the second B-channel is re-established, bringing transfer back to 128 kbps.
The same holds true if you decide to pick up the phone for an outgoing call. This is known as
‘Call Bumping’.
While a data connection is in progress, only one voice con nection can be established in order
to retain the data connection. In order to use DBA, verify that ‘Dyn amic Bandwidth
Allocation’ is enab led on the ‘Data’ pan el.
Two Voice Calls. When both B-channels are used for voice calls, data calls will not be allowed.
The user will be responsible for any new attempt at placing a Data call.