ZyXEL Communications Omni TA128 - Manual (Page 67)

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Once this is done, the ATD command will generate two
consecutive SETUP messages to invoke bundle initiation.
For the Northern Telecom switch, each BRI phone number can
only be called once at any given time. So if you dial this number, it
will report “busy” to any other incoming calls. In order to use two
B channels for aggregation, we must place two calls with different
phone numbers. To do this, separate the two numbers with a “+”
ATDI[phone_number_1]+[phone_number_2]
The answering TA128 determines that the call is a bundle request:
when AT&J3 is set, and two consecutive SETUP messages are
received. The two data calls are established as one message. The
phone company’s ISDN line splits it off into two messages. That is,
the ISDN network treats them as two independent calls. Finally, the
receiving side receives one bundled message into the computer’s
serial port.
The success of a bundle connection initiation is indicated by the
connect message reported to the DTE:
CONNECT 115200/V120M 128K/LAPD
or
CONNECT 115200/V120M 128K/LAPD/V42b (with data
compression)
If you are not using American ISDN, you can have a choice
between Multiple Link Protocol (MLP) or “cFos” channel
bundling (CCB) two bundle protocols. You can set them by using
the following commands:
ATS100=0 MLP channel bundling
ATS100=1 CCB channel bundling
Dialing pre-stored phone numbers
Use ATDSn, n=0,1,..,39, to dial the (n+1)th phone number twice
for both the bundle connections. Use ATDSn+Sm, (n and