Design for High Availability
Issue 3.4.1 June 2005
273
As reflected in the case studies presented in this section, an IP Telephony solution can be
configured to meet an enterprise’s desired level of availability. As shown by the examples,
Avaya IP Telephony solutions offer flexibility for designing a highly available system. The
optimum 99.999% availability within a site must include redundancy and optimized data network
design. For a geographically distributed system, the WAN is a major impediment to high
availability. For those enterprises with high inter-site call traffic, redundant WAN links
significantly enhance the full system availability. Such redundancy should provide sufficient
bandwidth to support the extra traffic in the event of a failure. In order to take full advantage of
link redundancy, the network should be designed with failure detection, multiple paths, and
failover capabilities. For more details on network design and configuration, see
Getting the IP
network ready for telephony
.
Table 64: Inter-site call Traffic Availability is Enhanced by Highly Available Data
Network. Percentage of traffic usage is listed in
Table 55
and is according to the
Communities of Interest (COI) Matrix presented in Section 2.1
Full Solution Availability Projected
Weighted Downtime min.
% of traffic generated in Atlanta
×
Annual
downtime minutes in Atlanta
(43.3% + 14.2%)
×
5.3 = 3
% of traffic generated in Boston
×
Annual
downtime minutes in Boston
(16% + 2%)
×
26 = 4.7
% of traffic between Atlanta and Boston
×
Annual downtime minutes due to failure
between Atlanta and Boston
(5.2% + 5.2%)
×
26.3 = 2.7
(5.2% + 5.2%)
×
5.3 = 0.56
% of traffic generated in Cleveland
×
Annual
downtime minutes in Cleveland
(7% + 0.4%)
×
59 = 4.4
% of traffic between Atlanta and Cleveland
×
Annual downtime minutes due to failure
between Atlanta and Cleveland
(2.7% + 2.2%)
×
26.3 = 1.3
(2.7% + 2.2%)
×
5.3 = 0.26
% of traffic between Boston and Cleveland
×
Annual downtime minutes due to failure
between Boston and Cleveland
(0.9% + 0.9%)
×
26.3 = 0.48
(0.9% + 0.9%)
×
5.3 = 0.1
Aggregated Downtime
16.58
(3 + 4.7 + 2.7 + 4.4+ 1.3 +0.48)
13.02
(3 + 4.7 + 0.56 + 4.4 + 0.26+ 0.1)
System Availability = 99.997%
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 ...