Frequently Asked Question
E1/T1 No link indication when connecting RJ-45
Last Updated 6 years ago
All of CTC Union equipment that features an RJ45 connector for T1 (DS1) or E1, follow the wiring standard of USOC RJ48C.
All devices are wired as NTU (pairs 1&2 receive transmissions while pairs 4&5 transmit).
When connecting our device to another NTU (such as a router or a PBX) a crossover is required.
Please note, an Ethernet crossover cable will NOT work!
All of these models use USOC RJ48C as NTU:
G703E1/Plus
FMUX01A E1/T1
FMUX01A/plus E1/T1
FMUX80,800,160,1600,101,1001
FRM220-E1/T1, Eoe1, E1/Data
IPM 1,4,16E1; 1,4,16T1
All devices are wired as NTU (pairs 1&2 receive transmissions while pairs 4&5 transmit).
When connecting our device to another NTU (such as a router or a PBX) a crossover is required.
Please note, an Ethernet crossover cable will NOT work!
All of these models use USOC RJ48C as NTU:
G703E1/Plus
FMUX01A E1/T1
FMUX01A/plus E1/T1
FMUX80,800,160,1600,101,1001
FRM220-E1/T1, Eoe1, E1/Data
IPM 1,4,16E1; 1,4,16T1