Telos NX12 user manual Hot Tip, Isdn S-interface cable

Installation  9

Hot Tip

Normally your telephone company should supply an RJ-11 style jack for the U interface. This is the same 4 or 6-pin plug used for analog lines. However, sometimes you may find an

8-pin RJ-45 style jack–and sometimes you may even be charged extra for it! If you have this situation, an RJ-11 plug can be inserted into the center of an RJ-45 jack to make things work. If you discover that the Telco charged you extra, be sure to request a refund!

ISDN Worldwide (outside the USA & Canada): The S/T Interface

The S-interface version of the Nx12 connects to the NT1 at one of its terminal jacks. The NT1 is sometimes generically called a NCTE (Network Channel Terminating Equipment) or, in some countries an NTBA.

Nx12 S-Interface (RJ-45)

PIN DESCRIPTION

1N/C

2N/C

3Transmit to network +

4Receive from network +

5Receive from network -

6Transmit to network -

7N/C

8N/C

ISDN S-interface cable

Use only an 8-conductor RJ-45 style cable. Unshielded twisted pair category 3 or better cable should be used.

ISDN S-Interface Cable (RJ-45)

PIN	COLOR	DESCRIPTION
1	White/Green	PS3 power +/ground (optional)
2	Green	PS3 power - (optional)
3	White/Orange	Transmit to network +
4	Blue	Receive from network +
5	White/Blue	Receive from network -
6	Orange	Transmit to network -
7	White/Brown	PS 2 power - (optional)*
8	Brown	PS 2 power +/ground (optional)*

TIA 568A Category 5 cable colors shown. Both ends are wired identically - not crossover. * The NX12 does not use these power connections

When fully wired, this cable has 4 twisted pairs ‘straight through’ just as with cables used for Ethernet. Both ends are wired identically. The outside pairs are not required and may be omit- ted.