COMSPHERE 3825Plus Modem
D-2 November 1996 3825-A2-GB30-20
JM8 to RJ11 Crossover Cable
For
2-wire leased-line connections to a JM8 network
interface, an 8-position to 6-position crossover cable (see
Figure D-1) must be used 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-divestitur
e Series 3002 (Category II, T
ariff #260)
service. Ther
e is a substantial differ
ence in transmit levels
permitted in the private line service and those permitted in
the public switched network. The industry standar
d is now
an 8-pin keyed modular jack known as the USOC JM8
(Bellcore T
echnical Refer
ence: TR-EOP-000242, Issue 1,
released May 1985.) When or
dering the installation of the
USOC JM8, specify the appr
opriate wiring options:
1. 2-wir
e operations
2. 4-wir
e operations w/o TEK leads
3. 4-wir
e operations with TEK leads
TEK leads ar
e for loopback purposes.
A 50-pin version is being consider
ed for multiple line
connections.”
A JM8 to RJ1
1 crossover cable may be ordered (part
number 125-0054-1531).
Figure D-1. Wiring Diagram — 8-Position to 6-Position Crossover Cable