Issue 3.4.1 June 2005
351
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:
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Change control
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Layer 2 mechanisms to increase reliability
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Layer 3 availability mechanisms
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Dial backup
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Convergence times
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.
Change control
contains more information on change control.
Summary of Contents for Application Solutions
Page 1: ...Avaya Application Solutions IP Telephony Deployment Guide 555 245 600 Issue 3 4 1 June 2005 ...
Page 20: ...About This Book 20 Avaya Application Solutions IP Telephony Deployment Guide ...
Page 21: ...Issue 3 4 1 June 2005 21 Section 1 Avaya Application Solutions product guide ...
Page 22: ...22 Avaya Application Solutions IP Telephony Deployment Guide ...
Page 106: ...Call processing 106 Avaya Application Solutions IP Telephony Deployment Guide ...
Page 124: ...Avaya LAN switching products 124 Avaya Application Solutions IP Telephony Deployment Guide ...
Page 139: ...Issue 3 4 1 June 2005 139 Section 2 Deploying IP Telephony ...
Page 140: ...140 Avaya Application Solutions IP Telephony Deployment Guide ...
Page 186: ...Traffic engineering 186 Avaya Application Solutions IP Telephony Deployment Guide ...
Page 204: ...Security 204 Avaya Application Solutions IP Telephony Deployment Guide ...
Page 228: ...Avaya Integrated Management 228 Avaya Application Solutions IP Telephony Deployment Guide ...
Page 274: ...Reliability and Recovery 274 Avaya Application Solutions IP Telephony Deployment Guide ...
Page 275: ...Issue 3 4 1 June 2005 275 Section 3 Getting the IP network ready for telephony ...
Page 276: ...276 Avaya Application Solutions IP Telephony Deployment Guide ...
Page 356: ...Network recovery 356 Avaya Application Solutions IP Telephony Deployment Guide ...
Page 366: ...Network assessment offer 366 Avaya Application Solutions IP Telephony Deployment Guide ...
Page 367: ...Issue 3 4 1 June 2005 367 Appendixes ...
Page 368: ...Appendixes 368 Avaya Application Solutions IP Telephony Deployment Guide ...
Page 394: ...Access list 394 Avaya Application Solutions IP Telephony Deployment Guide ...
Page 414: ...DHCP TFTP 414 Avaya Application Solutions IP Telephony Deployment Guide ...