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Cisco SCE8000 Installation and Configuration Guide, Rel 3.1.7
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Chapter 3 Cisco SCE8000 Topology and Topology-Related Parameters
Topology Considerations
— Will the system be used solely to monitor traffic flow, with report functionality only, or will it be
used for traffic flow control, with enforcement as well as report functionality?
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Monitoring and Control — The Cisco SCE8000 monitors and controls t raffic flow. Decisions
are enforced by the Cisco SCE8000 depending on the results of t he monitoring functions of the
Cisco SCE8000 and the configuration of the Service Control Application for Broadband or
Mobile solution.
In order to perform control functions, the Cisco SCE8000 must be physicall y installed as an inline
installation.
–
Monitoring only — The Cisco SCE8000 monitors traffic flow, but cannot control it.
Either an inline installation or an optical splitter or port SPAN installation may be used for
monitoring only.
• Size
A Cisco SCE8000 deployment can range from a single 10GBE link to multiple platforms in a
MGSCP topology.
A complete discussion on sizing the system is beyond the scope of this document. Information
regarding the number of Cisco SCE8000 platforms required is relat ed to the design considerations
'per link' (topology and redundancy factors) rather than to overall sizing of the system.
• Redundancy
Must the system be designed to guarantee uninterrupted Cisco SCE8000 functionality? If so, there
must be a backup Cisco SCE8000 platform (or a backup for each platform in an MGSCP topology)
to assume operation in case of failure of the primary device.
A backup SCE platform is connected in a cascade configuration with the prim ary SCE platform so
that, although all processing is performed only in the active Cisco SCE8000, the standby Cisco
SCE8000 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 Cisco SCE8000 fail.
Note that an MGSCP topology with multiple Cisco SCE8000 platforms provides more sophisticated
redundancy options, but the basic decision on each link is the same: d oes it require a standby SCE
platform or not?
• Link continuity
How should the Cisco SCE8000 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?
If link continuity is a high priority, an external optical bypass module ca n be installed on the link.
(See Link Continuity, page 3-9 and The Cisco SCE8000 Optical Bypass, page 2-8.)
Note In cascade configuration, installation of an external optical bypass module is required.
These issues determine two important aspects of system deployment and configuration:
• Physical topology of the system — The actual physical plac ement and connection of the Cisco
SCE8000 platform or platforms 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 th e desired
manner.