Telos Zephyr Xstream User Manual
Page 353
USER’S MANUAL
Appendix 9 – Modular Cable Guide 341
This special Ethernet "crossover" cable is used when two
computers (or a computer and another device such as a Zephyr
Xstream) need to be connected without using an Ethernet hub.
ISDN U interface Cable Pin‐out
The U interface, specified in the USA & Canada, is specified between the Telco and the user‐
provided NT1. The U interface is a robust interface meant for use on existing Telco copper plant.
It is a single copper pair. It is provided on the center pair of either a 6‐ position 4‐ pin miniature
modular jacks (RJ‐ 11 style) or a 8‐ position 8‐ pin miniature jack (RJ‐ 45 style). The standards
specify the compatibility between the 6‐ position plug and 8‐ position jack so either can be used.
For this reason, we prefer the 6‐ position connectors on cables, as they will work with either
type of receptacle.
ISDN U interface cable (typical)
PIN
FUNCTION
PIN
1 Not
Present 6
2
No Connection
5
3 Line
(R) 4
4
Line (T)
3
5 No
Connection 2
6
Not Present
1
Typical ISDN U interface cable. This is identical to a
POTS telephone cord. Polarity should not matter, so a
straight through cable is also acceptable.
ISDN U interface connector (USA & Canada only)
PIN
FUNCTION
1 No
Connection
2
No Connection
3 Line
(R)
4
Line (T)
5 No
Connection
6
No Connection
ISDN U interface connector. Note, the polarity of the line
connections should not matter.