Manual Operation; Table 26-2 Sonet Section, Line, And Path Descriptions; Table 26-3 Digital Hierarchies; Figure 26-1 Sonet Section, Line, And Path - Cisco BPX-BXM-155-8DX Installation And Configuration Manual

Chapter 26 Configuring SONET Automatic Protection System

Figure 26-1 SONET Section, Line, and Path

CPE

Table 26-2 SONET Section, Line, and Path Descriptions

Unit
Section
Line
Path
Table 26-3 provides a cross-reference between OC-n optical carrier levels and the equivalent STS-n and
SDH-n levels. It also includes the associated line rates.

Table 26-3 Digital Hierarchies

OC-n
Optical Carrier
OC-1
OC-3
OC-12
OC-48

Manual Operation

SONET Automatic Protection Switching configures a pair of SONET lines for line redundancy so that
the interface hardware automatically switches from a working line to the protection line or vice versa
within a specified period after an active line failure.
However, you may use the switchapsln command to manually control switching. The last user switch
request (switchapsln) per line pair is saved by switch software so that the APS can be configured
correctly in the event of a node rebuild.
Release 9.3.0, Part Number 78-10674-01 Rev. D0, July 2001
Section Section
Switch
STE
LTE
Line
Path
Description
A section is the fiber optic cable between two active elements such as simple
repeaters. The active element terminating these sections is called Section
Terminating Equipment (STE).
A line is a physical element that contains multiple sections and repeaters and is
terminated by line terminating equipment (LTE) at each end.
A path includes sections and lines and terminates at the customer premises
equipment (CPE).
STS-n Synchronized
Transport Signal
STS-1
STS-3
STS-12
STS-48
Section
Switch
STE
LTE
SDH-n
Synchronized
Line Rates (Mbps) Digital Hierarchy
51.84
155.52 SDH-1
622.08 SDH-4
2488.32 SDH-16
Cisco BPX 8600 Series Installation and Configuration
Tiered Management Control
CPE
STM-n
Synchronous
Transport
Module
STM-1
STM-4
STM-12
26-3