Failure And Recovery; Physical Installation; Redundancy - Cisco SCE 1000 Installation And Configuration Manual

Failure and Recovery

During setup of this topology, the configuration of the two SCE 1000 platforms is done through
multi-box configuration. This ensures that both hold the same configurations and policies. The
functional operation of switching from the active to standby, SCE 1000 is contingent upon the
fact that the two SCE 1000 platforms are in the same Domain. All configurations performed on
this Domain are automatically updated on both SCE Platforms. Both boxes should also be
assigned to the same Subscriber Domain. For more information on Domains, see the Cisco SCMS
Subscriber Manager User Guide.
The common protocols used for redundancy traffic switching between network elements such as
routers and switches in networks are Spanning-Tree in layer2, HSRP in layer3 (usually used in
data-centers), and other common routing protocols like OSPF or RIP.
When using routing/switching protocols that perform load balancing as well, the load balancing
Note
capabilities should be disabled.
The transition to the backup SCE 1000 platform is transparent. Once the routers/switches detected
that traffic has been cut, they start sending traffic through the redundant link. After this occurs, the
failed SCE 1000 can be fixed/replaced with no downtime, since the box is effectively
disconnected from the network. After fixing/replacing the failed SCE 1000, you must copy the
configuration of the current active SCE 1000 to the fixed/replaced SCE 1000.
The backup and restore procedures used for copying policies and Service Configurations from
one SCE 1000 to the next are detailed in the Service Control Application Suite for Broadband
User Guide.

Failure and Recovery

It is important to decide how the system should behave in case of the failure of the SCE 1000,
both during the time that the unit is down and after recovery. This decision is influenced by
several factors:
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Physical Installation

In a link connection via an external optical splitter, SCE 1000 failure does not affect traffic flow,
which continues through the external optical splitter. When the SCE 1000 detects a failure that
requires a recover by reboot, it immediately switches to Cutoff mode, stopping all traffic flow
over the link until the SCE 1000 unit is restored to operation.
When operation resumes, the defined operational bypass mode is automatically resumed.
The configuration of a bump-in-the-wire installation depends on the remaining two factors.
Cisco SCE 1000 2xGBE Installation and Configuration Guide
3-6
Physical installation (connection mode)

Redundancy

Relative importance of maintaining connectivity vs. the continuity of the value-added services
that the SCE 1000 enables.
Chapter 3 Topology
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