ZyXEL Communications ACCESSING INTERNET & INTRANET omni series - Manual (Page 72)

60 V.120 ISDN Communications
Speeds 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 (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). It is called a “Bundle Connection”.
The type of channel bundling described in the V.120 section is
supported only between the following ZyXEL products: omni.net
series, Omni TA128, or Elite 2864I, and uses Multiple Link Protocol
(MLP) and “cFos” channel bundling (CCB).
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.
Making a Bundled Call with V.120
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.
Type:
ATB20 (Set B channel protocol to V.120)
AT&J3 (Set the TA to make a bundled call)
Type:
AT&WZ (If you want to save the setting)