Technical Reference for ZyXEL omni.net series

Making V.120 and X.75 Bundled CallsSpeeds of 128Kbps

BRI ISDN consists of three (2B+D) logical channels. Each B-channel can be used independently for a dial-up connection running at 56Kbps or 64Kbps (Kbps = Kilo (1000) bits per second).

The two B-channels can be used together for a single data connection to provide 112K (with In-Band Signaling) or 128K (when Out-of-Band Signaling is used). This is called a "Bundled Connection".

Identifying your Line Provisioning

For bundled connections, the two B-channels of your ISDN line must be able to handle data circuit switch connections with unrestricted 64K or 56Kbps line speeds. Two separate data calls will be established consecutively.

NOTE: V.110 protocol does not support bundled call..

V.120 Bundled Call

A bundled V.120 connection is initiated at the calling site when [ATB20] (B-channel protocol V.120) has been selected and the channel bundling mode has been enabled by an [AT&J3] command.

The channel bundling command [AT&J3] must be set on both the calling and receiving sides, otherwise a single channel connection will be made.

AT Command

 

Description

 

 

 

ATB20<Enter> Set B-channel protocol to V.120.

AT&J3<Enter> Enable the omni.net ISDN TA to make a bundled call.

AT&WZ<Enter> If you want to save the setting.

Table 48. V.120 Bundled Call AT Command (1)

While 'ATJ&3' allows to make a bundle call in both call and answer modes, other bundled call settings are

8-7