Information About Redundancy; Redundancy; Two Platforms On Parallel Links In Bump-In-The-Wire Topology - Cisco SCE 1000 Installation And Configuration Manual

Chapter 3 Information About Topology

Information About Redundancy

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Redundancy

When a high degree of reliability is desired, a second SCE 1000 Platform should be installed to provide
backup operation capabilities. This redundant SCE 1000 guarantees uninterrupted functioning of all
SCE 1000 operations.
Redundancy is possible in inline installations only.
Note
A single SCE 1000 platform does not provide redundancy for SCE 1000 control functions. In case of
failure of the SCE 1000 unit, the SCE 1000 simply bypasses the traffic; the traffic link is not cut, but no
control or monitoring functionality is available.

Two Platforms on Parallel Links in Bump-in-the-Wire Topology

Using two SCE 1000 platforms on parallel links provides redundancy for all SCE 1000 features. In case
of failure in the active platform, the backup SCE 1000 unit takes over.
Using redundant SCE 1000 platforms is applicable as an overlay to a customer's redundant topology, on
condition that the entire traffic of a specific subscriber (end station, subnet or VLAN) is flowing through
one link only. Both links may be active, providing that the subscriber traffic is mutually exclusive.
This redundancy solution addresses any failure in the SCE 1000 platform itself. It is based on the idea
that any fatal hardware or software failure will cause the platform to "cut" the link. A "cut" link will
cause the routers/switches on both ends to switch the traffic to the standby link. On the standby link, the
traffic is analyzed and policies enforced by the standby SCE 1000, which, after the failure, acts as the
active SCE 1000.
Note that when both links are simultaneously independently active and redundant for the other link (as
is the case when HSRP with two virtual routers is used), if one link fails, its traffic is directed to the other
link. However, the overall supported load in the link that is now carrying all the traffic is only equal to
one link, not two.
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
Subscriber Manager User
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.
OL-26790-01
Redundancy, page 3-7
Two Platforms on Parallel Links in Bump-in-the-Wire Topology, page 3-7
Guide.
Cisco Service Control Management Suite
Cisco SCE 1000 2xGBE Installation and Configuration Guide

Information About Redundancy

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