User manual

4300T User Manual Edgewater Networks, Inc.
Version 1.7 42
VoIP Survivability Configuration
The high availability of voice services is a fundamental requirement for enterprises
deploying their own IP telephony equipment or subscribing to hosted VoIP services.
In both cases providing reliable communications to remote branch offices is costly
usually involving the installation of local call processing servers or additional wide
area network (WAN) links to these locations.
Edgewater’s VoIP survivability enhances the reliability of VoIP services to branch
offices in a cost effective manner by providing local call switching in the event of
WAN link failures or a loss of connectivity to network based call processing servers.
VoIP survivability is an orderable software option for Edgewater’s EdgeMarc Series
appliances. EdgeMarc appliances are flexible networking devices that can also be
configured to provide IP routing, optional T1 WAN link termination, resolve
NAT/firewall traversal problems, ensure high quality voice using QoS, monitor voice
call quality and provide comprehensive security for the LAN using a VoIP and data
firewall.
Key benefits and features of VoIP survivability
Edgewater’s VoIP survivability offers the following important benefits:
• Continuity of voice services to branch offices during WAN link failures or
failures in network based call processing servers
• Significant savings over alternative solutions requiring redundant call
processing servers or multiple WAN links
• Simplified design that is easier to manage than alternative solutions requiring
maintenance of multiple dial plans in distributed call processing servers and
complex routing
Survivability features:
• Application layer based monitoring of call processing servers to determine
connectivity
• Automatic detection of loss of connectivity to call processing servers caused
by WAN link failures, network congestion or call processing server software
failure
• Automatic return of call control to network based call processing servers once
connectivity has been restored
• Configurable timers to determine call processing server connectivity
• Call processing server connectivity status indicators
• Support for multiple call processing servers using DNS
• Reporting of the currently active call processing server in environments using
multiple call processing servers
• Local call switching between VoIP endpoints and premises based PSTN
gateways during WAN link failures or other failures that prevent connectivity
to network based call processing servers
• Calling features such as transfer, hold and conference are provided by
EdgeMarc Series appliances
• Simplified setup that creates a local dial plan in the EdgeMarc appliance by
monitoring traffic to network based call processing servers