Prosody compact PCI installation guide
28
Line Interface
Each network port on the card carries one 23-channel service connection via a screened twisted
pair cable of 100 ohm characteristic impedance. There is one transmit pair and one receive pair.
The card is designed to connect to a Data Service Unit (DSU) (NT1) as supplied by NTT.
Network Cable Pinout
The 8-contact RJ45 Telephone Modular Plug on the cable between the card and the network
must be wired as follows:
PIN
SIGNAL
FUNCTION
Direction
4 LTT
Transmit
(tip) output
5 LTR
Transmit
(ring) output
1 LRT
Receive
(tip) input
2 LRR
Receive
(ring) input
The cable and plug must be shielded types to ensure EMC compliance.
If a cable is to be produced to wire into a network trunk connection, the connector on the
network end of the cable must be wired as appropriate for the network terminating unit (DSU)
provided.
A 'cross-over
' cable is required to connect two T1 ports 'back-to-back', for example, when one port is to run
an exchange end emulation and the other port a user end application. The cable should be
wired as follows:
User End
Exchange End
4 to 1
5 to 2
1 to 4
2 to 5
