Cisco Systems 8600 Series manual Switch Software Description, Connections and Connection Routing

Switch Software Description

Since the BPX switch is designed to be part of a larger communications network, it is capable of synchronizing to higher-level network clocks as well as providing synchronization to lower-level devices. Any network access input can be configured to synchronize the node. Any external T1 or E1 input can also be configured to synchronize network timing. A clock output allows synchronizing an adjacent IPX or IGX switch or other network device to the BPX switch and the network. In nodes equipped with optional redundancy, the standby hardware is locked to the active hardware to minimize system disruption during system switchovers.

The BPX switch does not accept clock from an IPX switch. The BPX Service Node can be configured to select clock from the following sources:

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External (T1/E1)

Line (DS3/E3)

Internal

Switch Software Description

The Cisco WAN switching cell relay system software shares most core system software, as well as a library of applications, between platforms. System software provides basic management and control capabilities to each node.

IPX, IGX, and BPX node system software manages its own configuration, fault-isolation, failure recovery, and other resources. Since no remote resources are involved, this ensures rapid response to local problems. This distributed network control, rather than centralized control, provides increased reliability.

Software among multiple nodes cooperates to perform network-wide functions such as trunk and connection management. This multi-processor approach ensures rapid response with no single point of failure. System software applications provide advanced features that may be installed and configured as required by the user.

Some of the many software features are:

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Automatic routing of connections (AutoRoute feature).

Various classes of service that may be assigned to each connection type (OptiClass feature).

Bandwidth reservation on a time-of-day basis.

Detection and control of network congestion with ABR with VSVD or ForeSight algorithms.

Automatic self-testing of each component of the node.

•Automatic collecting and reporting of many network-wide statistics, such as trunk loading, connection usage, and trunk error rates, as specified by the user.

The system software, configuration database, and the firmware that controls the operation of each card type is resident in programmable memory and can be stored off-line in the Cisco StrataView Plus NMS for immediate backup if necessary. This software and firmware is easily updated remotely from a central site or from Customer Service, which reduces the likelihood of early obsolescence.

Connections and Connection Routing

The routing software supports the establishment, removal and rerouting of end-to-end channel connections. There are three modes:

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Automatic Routing—the system software computes the best route for a connection.

Manual Routing—the user can specify the route for a connection.

Introduction 1-19