V-Tap ISDN PRI Manual EN v1.3 Okt 2018 © 2018 Vidicode 40
8
ISDN PRI RJ45 connectors & wiring
The connectors used on the PRI to connect the telephone trunk (E1 only)
and the PBX, are RJ45 modular types. The pin-assignment is based on
the G.703 standard.
Please note that the pinning of the 2 IN/OUT connectors is different.
Looking inside the PRI connectors, pin 1 is on the
right-hand
side of the
RJ45 connector.
The Rx twisted pair and Tx twisted pair have approx. 120 Ohm
impedance.
The PRI interface circuits support the ‘Short Haul’ interface
implementation. Generally, this means that the hazard protection
scheme of the PRI E1 interface allows wiring inside buildings only.
Cable Specification suggestion
24AWG / 2 pairs / 100-120 Ohm impedance, no shielding required.
Generally, CAT 2 cable or better will work fine.
For use in The Netherlands only
The pin assignment on the PRI allows the use of standard 1:1 CAT 5
network cable for the connection to the incoming line from the provider
unit and the outgoing connection to the PBX. It has shown that this is
also the situation for many other countries.