Cisco Systems SCE 2000 4/8xFE manual Functionality, Number of links, Redundancy

Chapter 3 Topology

Topology Considerations

•Number of links — The SCE 2000 may be connected to one or two FE links. This is relevant for both Inline and Receive-Only topologies.

•Redundancy — Must the system be designed to guarantee uninterrupted SCE 2000 functionality? If so, there must be a backup SCE 2000 Platform to assume operation in case of failure of the primary device.

•Link continuity — How should the SCE 2000 respond to platform failure with regard to link continuity? Should traffic flow continue even though the unit is not operating, or be halted until the platform is repaired/replaced?

These issues determine three important aspects of system deployment and configuration:

•How many SCE 2000 Platforms are needed and how will they be installed?

•Physical topology of the system — The actual physical placement of the SCE 2000 in the system.

•Topology-related configuration parameters — The correct values for each parameter must be ascertained before configuring the system to make sure that the system will function in the desired manner.

Functionality

The SCE 2000 can serve one of two general functions:

•Monitoring and Control — The SCE 2000 monitors and controls traffic flow. Decisions are enforced by the SCE 2000 depending on the results of the monitoring functions of the SCE 2000 and the configuration of the Service Control Application for Broadband or Mobile solution.

In order to perform control functions, the SCE 2000 must be physically installed as an inline installation and the connection mode must be “inline”.

•Monitoring only — The SCE 2000 monitors traffic flow, but cannot control it.

Either an inline installation or an external switch installation may be used for monitoring only. In the latter case connection mode must be “receive-only”.

Number of links

The SCE 2000 can be deployed in a single FE link or in two FE links. The two-link topology may implement load-sharing and the SCE 2000 in this case is able to process both directions of a bi- directional flow even if they split to both links.

Redundancy

When a high degree of reliability is desired, a second SCE 2000 Platform should be installed to provide backup operation capabilities. The combination of two SCE 2000s guarantees uninterrupted functioning in case of a failure of one of the platforms. The two SCE 2000s are cascaded, so that, although all processing is performed only in the active SCE 2000, the standby SCE 2000 is constantly updated with all the necessary information so that it can instantly take over processing the traffic on the data links should the active SCE 2000 fail.

If only preservation of the network links is required, and uninterrupted functionality of the SCE 2000 is not required, a single SCE 2000 is sufficient.

Cisco SCE 2000 4/8xFE Installation and Configuration Guide

3-2 OL-7826-05