Technical Reference for ZyXEL omni.net series

available for more flexibility, as shown below:

AT&J0

Disables B-channel bundling.

 

 

AT&J1

Enables B-channel bundling in answer mode only.

 

 

AT&J2

Enables B-channel bundling in call mode only.

 

 

AT&J3

Enables B-channel bundling in both call and answer modes.

 

 

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 “+” sign after the ATD command, as shown below:

&ATDI[phone_number_1]+[phone_number_2]<Enter>

The answering ISDN TA 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 its 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)

Table 49. V.120 Bundled Call AT Command (2)

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