Specifications

If the T1 is coming from the demarcation point please use a straight thru T1 cable to connect to the Rhino
OST T1 card. In some cases additional cable must be run from the carrier’s demarcation point to the
customer’s suite or nearby “phone room”.
T1 Line Interface on RJ45 - 8 pin Modular T1 jack
Pin Number Signal To/From What?
1 Receive Ring Coming From T1 (Network)
2 Receive Tip Coming From T1 (Network)
3 Not connected
4 Transmit Ring Going To T1 (Network)
5 Transmit Tip Going To T1 (Network)
6 Not connected
7 Not connected
8 Not connected
The maximum cable length for a T1 Network (DS1-1) connection is suggested as follows. Reliable T1
cabling distances depend on which type of cable is used. It is strongly recommended that only shielded
cable be used as part of any T1 installation. For best results use: shielded 22 AWG T1 cable (ABAM 600).
ABAM 600 T1 Cable
T1 Network (CSU) can go as far as 6,000 feet
ABAM 600 Cable Specifications:
Nominal Impedance: 100 ohms +/- 5% at 772 kHz.
Insertion Loss: Better than 7 dB per 1,000 feet at 1.544 MHz.
Better than 5 dB per 1,000 feet at 772 kHz.
Far-End Crosstalk: Better than 85 dB per 1,000 feet at 1.544 MHz.
Better than 90 dB per 1,000 feet at 772 kHz.
Near-End Crosstalk: Better than 80 dB per 1,000 feet at 1.544 MHz.
Better than 85 dB per 1,000 feet at 772 kHz.
Shields: Transmit and receive pairs are individually shielded with
aluminum/polyester tape.
If you used unshielded cable you could experience problems. When this type of cable is used, transmit and
receive pairs are usually run in separate cables to avoid crosstalk which often occurs in unshielded cables.
Failure to use separate cable bundles for transmit and receive can result in the CSU LINE port clocking
onto itself (due to crosstalk) with as little as 10 feet of un-terminated (unshielded) telephone cable attached.
The CSU can thus show a normal framed status when the far end of the telephone wiring is actually
disconnected. Again, this is due to crosstalk between pairs in the same cable bundle. This is true of any
CSU installation using any kind of unshielded twisted pair cable.
Rhino Equipment Corp. • 8240 S. Kyrene Rd. • Suite 107 • Tempe, AZ 85284 • [phone]
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