Chapter 3 | Topology |
Redundancy
An external splitting installation is referred to as
Note that in an external splitting installation, the SCE 1000 has only traffic monitoring capabilities.
Note
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.
Note Redundancy is possible in inline installations only.
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.
Cisco SCE 1000 2xGBE Installation and Configuration Guide
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