4RF Aprisa XE User Manual - page 112
110 | Configuring the Traffic Interfaces
Aprisa XE User Manual
E1 CAS to DFXS Circuits
Function
E1 CAS to DFXS circuits can be provisioned over an Aprisa XE link by using a DFXS interface card at the
customer end of the link and a QJET at the exchange end of the link. The QJET E1 interface connects to
an exchange or PBX Digital Trunk Interface (DTI) to provide FXS foreign exchange circuits.
The Aprisa XE can interconnect at E1 to an exchange / PBX DTI if the DTI is capable of providing standard
1 bit channel associated signalling (CAS).
Forward
Af
Backward
Ab
Idle
1
Idle
1
Ringing
0
Loop (Off hook)
0
The signalling functions provided with a 1 bit CAS protocol are:
Ring cadence transmission
Ring trip
Off hook
Switch hook flash
Decadic dialling
The speech path functions as normal and provides:
Transmission of tones (e.g. dial tone, ring tone)
Caller ID
DTMF dialling
Speech
Setup
Cross connect the voice channel between the QJET and the DFXS card.
Cross connect the signalling (A bit only) using ‘4 wire compatible’ mode between the QJET and the DFXS
card.
Configure the E1 spare CAS bits to be compatible with the DTI (see ‘QJET Spare CAS Bit Control’ on page
165). The standard spare bit states are B = 1, C = 0, D = 1.
DFXS to DFXS Hotline Circuits
Function
A ‘Hotline’ circuit can be provisioned over an Aprisa XE link by using a DFXS interface card at both ends of
the link. When one phone goes off hook, the other phone rings and vice versa.
A 1 bit CAS protocol is used to signal between the DFXS interfaces:
Forward
Af
Backward
Ab
Idle
1
Idle
1
Ringing
0
Loop (Off hook)
0
Setup