Avaya 555-245-600 manual Network recovery, Change control

Network recovery

Conventional wisdom holds that network reliability is typically 3-9s (99.9%) on a LAN, and 2-9s (99%) on a WAN. The leading causes of network failure are a WAN link failure, administrator error, cable failure, issues that involve connecting new devices or services, and malicious activity, including DoS attacks, worms, and viruses. Somewhere lower down on the list are equipment failures. To achieve the highest levels of availability, it is important that a strong change control policy and network management strategy be implemented.

There are numerous techniques for improving the reliability of data networks, including spanning tree, self-healing routing protocols, network management, and change control. This section discusses the following techniques:

●Change control

●Layer 2 mechanisms to increase reliability

●Layer 3 availability mechanisms

●Dial backup

●Convergence times

●The Converged Network Analyzer

Change control

Change control describes a process by which an organization can control non-emergency network changes, and reduce the likelihood of administrator errors that cause network disruption. It involves carefully planning for network changes (including back-out plans), reviewing proposed changes, assessing risk, scheduling changes, notifying affected user communities, and performing changes when they will be least disruptive. By implementing a strict change control process, organizations can reduce the likelihood of administrator errors, which are a major cause of network disruption, and increase the reliability of their networks.

Issue 6 January 2008 339