Specifications

CHAPTER
5-1
Cisco MGX 8850 (PXM1E/PXM45), Cisco MGX 8950, Cisco MGX 8830, and Cisco MGX 8880 Configuration Guide
Release 5.0.10, OL-3845-01 Rev. B0, August 16, 2004
5
Preparing SRM Cards for Communications
To prepare SRM cards for communication, you need to know which SRM features will be used. Because
SRM cards operate as extensions of the PXM cards, they are initialized when you initialize the PXM
card, so the initialization procedure required for most service modules is not required for SRM. SRM
cards provide the following features:
• 1:N redundancy support for select service modules
• Bulk distribution
• Bit error rate testing (BERT)
Note For more information on BERT, see the Managing Bit Error Rate Tests section of Chapter 9, “Switch
Operating Procedures.”
SRM cards can operate as standalone cards or as redundant cards. As described in the Cisco MGX 8850
(PXM1E/PXM45), Cisco MGX 8950, Cisco MGX 8830, and Cisco MGX 8880 Hardware Installation
Guide, Releases 2 Through 5, MGX switches are preconfigured for SRM card redundancy, and this
redundancy must match the configuration (standalone or redundant) of the PXM card. After installation,
no configuration is required to establish a standalone or redundant SRM configuration.
When installed, SRM cards automatically support 1:N redundancy for 8-port service modules with T1
or E1 interfaces as listed in the Cisco MGX 8850 (PXM1E/PXM45), Cisco MGX 8950, Cisco MGX 8830,
and Cisco MGX 8880 Hardware Installation Guide, Releases 2 Through 5. To configure 1:N redundancy
for service modules, refer to Chapter 4, “Preparing Service Modules for Communication.”
Tip If you are not using the SRM bulk distribution feature, you can skip reading the rest of this chapter,
which describes how to configure bulk distribution on SRM cards.
The bulk distribution feature enables the SRM to receive T1 and E1 traffic that has been multiplexed into
a T3 or OC-3 line and route that traffic to the appropriate service module for processing. Responses are
sent back through the SRM to the equipment at the other end of the T3 or OC-3 line.
When bulk distribution is used, you must bring up and optionally configure the T3 or OC-3 lines on SRM
back cards. For redundant SRM cards with SONET/SDH interfaces, you have the option of configuring
line redundancy for the attached OC-3 lines. For all cards that use bulk distribution services, you must
configure links, which are logical mappings between the lines on the service modules and the channels
embedded in the T3 or OC-3 lines connected to a SRM.