Table of Contents
Advertisement
Protection Switching
Protection switching is described in the following
subsections.
OC-3 Equipment MUX Protection
Equipment protection is provided for the OC-3 network
interface through redundant MUX equipment.
OC-3 Facility Protection
Facility protection is provided by each OC-3 MUX
module having its transmit and receive over its own pair
of fiber facilities. A fiber cut on one module, therefore,
can only affect that module.
OC3 Automatic Protection Switching (APS)
Facility/Path/Equipment
Each access module independently selects the terminal
receive signal from one of the two OC-3 MUX modules.
The Total Access shelf provides a single DS3 transmit
output for each DS3, and the transmit data stream is
provided by one of the two OC-3 MUX modules.
The OC-3 MUX receives three STS-1 paths from the
receive OC-3 signal. If a path on the OC-3 MUX is
selected to be dropped through either APS or MPS, that
path on that OC-3 MUX is assigned the online state.
Each path can be online on either module, independent
of the others. The APS uses the following criteria to
select the data stream from a OC-3 MUX:
• The standby OC-3 MUX detects an equipment
failure on the online OC-3 MUX.
Shelf:
1
Slot:
Unacknowledged Alarms: None
61181031L3-5A
B
Total Access System
Adtran OC-3 L3 Mux
1.
Configuration
2.
Provisioning
3.
Status
4.
Alarms
5.
Test
6.
Performance Monitoring
7.
Protection Configuration
8.
STS-1 Mapping
9.
DS1 Mapping Status
10.
Path Trace
11.
Synchronization Messages
12.
Display Options
Selection:
'?' - System Help Screen
Figure 3. Main Menu
• The online OC-3 MUX detects a receive OC-3
facility failure (both DS3s and access modules
switch).
• The online OC-3 MUX detects an equipment failure
(both DS3s and access modules switch).
• The online OC-3 MUX detects an STS-1 Path
failure and the offline OC-3 MUX does not (DS3 or
the access modules provisioned to the STS-1 path
will switch)
• APS is not inhibited.
On detection of failure and if any one of the above
criteria is met, the selected path will switch from the
online to the offline MUX, which will then become the
online MUX for the path. The APS transition is
completed within 60 ms after the switch decision
occurs.
APS may be manually locked out through the craft
interface, front panel switch, SNMP, or TL1 interface.
Refer to Table 4.
The OC-3 MUX MPS may be manually asserted
through the craft interface or the front panel switch.
4. MENUS
This section describes the OC-3 MUX menu structure
and options. Refer to Appendix B OC-3 MUX Menu
Tree for a detailed illustration of the OC-3 MUX menus.
Figure 3 represents the OC-3 MUX main menu screen.
Use this screen to access the OC-3 MUX module for
various functions such as provisioning, performing
loopback tests, and mapping.
01/06/03 11:13
7
Advertisement
Table of Contents
