ISDN B-channel data
Z-Edge 64 Configuration Guide
89
If you need to modify the signaling and ring frequency, update the
analog-fxs-cfg-profile for each interface. For example:
zSH> update analog-fxs-cfg-profile 1-1-3-0/voicefxs
signal-type: ----> {fxsloopstart}
ring-frequency: -> {ringfrequency20}
modify if required
ring-back: ------> {off}
modify if required
....................
Save changes? [s]ave, [c]hange or [q]uit: s
Record updated.
ISDN B-channel data
The ATM Forum’s specification for carrying voice over ATM
(AF-VMOA-0145) details the delivery of ISDN BRI service over ATM
adaption layer 2 (AAL2) virtual circuits. Based on this specification, a
separate ATM virtual channel connection (VCC) is used for each of the two
ISDN B (bearer) channels and the ISDN D (signalling) channel. The ISDN B
channels can be used to carry voice calls as well as dial-up data calls to fax
machines or modems.
In traditional time division multiplexing (TDM) networks, the ISDN D
channel notifies the receiving terminal equipment if the B channel will carry
voice or dial-up data. But in ATM networks, the ISDN D channel is relayed
and there is no way to look at the D channel signalling information. Therefore
Parameter
Description
signal-type
The method by which an off-hook condition is indicated.
Values:
fxsloopstart
Default: fxsloopstart
ring-frequency
Rate in cycles per second (Hertz) at which polarity reversal
occurs on ringing.
Values:
ringfrequency20
ringfrequency25
ringfrequency30
ringfrequency50
Default: ringfrequency20
ring-back
The ring back is requested if this variable is set to on.
Values:
on
off
Default: off
