The Five Star Approach to Guidelines for Survivable IP-Centrex
Survivability is a key challenge which should be meticulously addressed before designing and deploying an IP Centrex or distributed IP-PBX servers. This article details AudioCodes “Five Star Approach” to guidelines for survivable IP Centrex/IP-PBX services. The Five Star Approach has been recognized by IT & telecom managers as highly essential when selecting an IP Centrex/IP-PBX service provider that can ensure survivability and create a reliable IP-based telephony network.
Standards Based Survivability Implementation
Why shouldn’t you redesign your network to support survivability?
The primary requirement from any survivability mechanism is to be fully based on standard protocols such as the commonly used SIP to ensure the very basic level of integration within a customer’s existing VoIP network. Implementing the SIP based survivability mechanism, guarantees interworking with many IP Centrex/IP-PBX servers as well as IP Phones and VoIP Gateways. This certainly enables the customer to have the freedom to choose its VoIP implementation, components and service provider.
Scalable Solution - Growing with your Enterprise
Can your survivability application scale up with the rest of your telephony network?
Looking ahead, enterprises should consider a possible expansion of their telephony network which will entail an extension of the survivability services. In order to protect their initial investment, the originally deployed survivability application should be designed as a scalable solution enabling expansion of its services in the future. Lack of these features will pressurize the customer to replace their original survivability equipment and re-invest in a new server with a higher performance level. An efficient, scalable solution should enable system upgrades either by means of software updates or the installation of an additional survivability application on top of the original one, thereby extending the number of protected users in an enterprise.
Redundancy Mechanism for Survivability Applications
What happens if Murphy’s Law strikes twice?
What happens if the survivability application ceases while in “emergency” mode? This question can be addressed by deploying a redundant survivability application in customers’ premises. This redundancy mechanism should maintain telephony services in the event that one of the original survivability applications halts during an emergency scenario.
Advanced Support for Emergency Calls (e.g. 911)
Safety is paramount!
The most elementary expectation from any survivability application is to enable emergency calls from enterprise headquarters or its remote branches. In addition, the survivability mechanism should be able to detect such calls and prioritize them accordingly, even if it means to tear down other “regular” calls. Prioritizing emergency calls is essential during “emergency” mode since occasionally survivability applications do not maintain the same voice sessions throughput as compared to the original IP-PBX or IP Centrex servers.
Maintain Maximum Functionality level in Emergency Mode
Should we be content with basic call connectivity during emergency operational mode?
Sometimes it is not enough to have just basic calls during emergency scenarios as other functionalities are required and may even be considered mandatory. For example, during normal operational mode, telephone numbers within the enterprise can be reached by dialing only their suffix extensions instead of dialling the complete number. These services are critical for the enterprise’s normal telephony services and should be supported by the survivability application during network failure.
AudioCodes Stand Alone Survivability (SAS)
Based on extensive field experience addressing enterprise and service provider survivability requirements, AudioCodes has developed and implemented the Stand Alone Survivability (SAS) feature across its Media Gateways. SAS is an application agent which is installed in the enterprise’s headquarters and/or branch office premises to ensure continuous telephony service during network outage scenarios such as WAN failure, thus preventing communication with the central server.
AudioCodes SAS adheres to the Five Star Approach guidelines, and provides reliable and continuous telephony services.
For further information regarding the “Five Star Approach” and survivability in an enterprise telephony network please refer to the “Survivability in IP Centrex and Distributed IP-PBX Environment” white paper.
