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Cisco SCE 2000 4xGBE Installation and Configuration Guide
OL-21096-02
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The External Optical Bypass Module
Revised: December 24, 2010, OL-21096-02
Introduction
The SCE 2000 platform External Optical Bypass module preserves the service provider GBE links in
case of complete power failure of the SCE 2000 platform, or for implementing a maintenance window.
The SCE 2000 platform state-of-the-art Service Control platform is being deployed at ISPs, Cable and
Wireless Tier1 provider networks, and is therefore required to comply with the carrier grade availability
requirements of these mission critical networks.
The SCE 2000 platform already includes an internal Electrical Bypass module that puts the SCE 2000
platform into bypass state in case of a software or hardware failure at the platform main board, thereby
preserving the GBE network link.
The External Optical Bypass module provides additional service protection by enabling automatic
preservation of the network GBE link in two additional important scenarios:
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Complete loss of power in the SCE 2000 platform — The SCE 2000 platform includes redundant
Power Supply Units and redundant power feeds, in both the DC and AC versions. However, in case
either both PSUs fail, or both power feeds stop providing power to the SCE 2000 platform
simultaneously, the network link will be preserved by the External Optical Bypass module.
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Maintenance window implementation — In certain situations the SCE 2000 platform should be
pulled from the network for replacement, such as:
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Hardware failure in the SCE 2000 platform.
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Hardware upgrade on the SCE 2000 platform
In these cases, a maintenance window is implemented, during which the SCE 2000 platform is
pulled from the network. It may be replaced by another SCE 2000 platform, either almost
immediately, or after several hours or days. An External Optical Bypass module enables the
implementation of such replacement while preserving normal operation of the network link.
The External Optical Bypass module is another important component in the Cisco overall carrier-grade
solution for high-availability service provider networks
