Paradyne Comsphere 3920Plus Installation And Operation Manual page 221

For 2-wire leased-line connections to a JM8 network interface, use an 8-position to 6-position
crossover cable (Figure C-3) according to the following FCC requirements:
"The RJ series of jacks should not be used for connecting data equipment to nonswitched
private line networks — specifically, the service equivalents of the pre-divestiture Series 3002
(Category II, Tariff #260) service. There is a substantial difference in transmit levels
permitted in the private line service and those permitted in the public switched network. The
industry standard is now an 8-pin keyed modular jack known as the USOC JM8 (Bellcore
Technical Reference: TR-EOP-000242, Issue 1, released May 1985.) When ordering the
installation of the USOC JM8, specify the appropriate wiring options:
TEK leads are for loopback purposes.
A 50-pin version is being considered for multiple line connections."
8-POSITION
PLUG PIN NO.
1
2
3
4
5
6
7
8
Figure C-3. Wiring Diagram — 8-Position to 6-Position Crossover Cable
3920-A2-GN31-10
2-wire operations
4-wire operations w/o TEK leads
4-wire operations with TEK leads
April 1995
Pin Assignments
6-POSITION
PLUG PIN NO.
1
2
3
4
5
6
C-5