Cisco ASR 5000, Руководство по установке

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External BITS timing is an alternative to using clock signals derived from an ATM port on an OLC2, or
an ANSI SONET STS-3/SDH STM-1 port on a CLC2. (Line-derived clocking requires that the SPIO be
equipped with the optional Stratum 3 clock module.) For additional information, refer to the
ATM Port
Configuration Mode Commands and Channelized Port Configuration Mode Commands chapters of the
Command Line Interface Reference .
Important
Always refer to the interface and signaling specifications in the OEM documentation supplied with the
BITS source. Your NOC may also have detailed specifications for distributing the BITS clock signals to
network devices such as the ASR 5000.
Important
BITS E1 BNC Interface
The BNC version of the SPIO employs a 75-ohm coaxial BNC connector that accepts an analog E1 BITS
signal. The following figure shows the BITS BNC timing interface.
Figure 36: SPIO E1 BITS BNC Pinout
Use 75-ohm coaxial cable (RG-59/U) between the BITS and the SPIO BNC interface to carry the E1 signal.At
the SPIO, terminate the cable with a 75-ohm BNC male connector.
BITS T1 3-Pin Interface
The 3-pin version of the SPIO employs a wire-wrap connector that accepts a T1 (DS1) BITS data signal (all
ones). The following figure shows the BITS timing interface wire-wrap pin-out.
Figure 37: SPIO T1 BITS Wire-Wrap Pinout
Use 22 AWG, twisted-pair, 100-ohm shielded cable between the BITS and SPIO wire-wrap interface to carry
the DS1 signal.
ASR 5000 Installation Guide
96
Cabling the Switch Processor Input/Output Line Card
BITS E1 BNC Interface