This document explains some otherwise undocumented features in the Convergence products, and also gives some hints for specific SIP scenarios. It explains how to use multiple ports for accepting SIP messages, the configuration for sending traps when changing the survivability mode status, adapting the VIA headers in SBC sceanrios, as well as the use of DNS SRV in VoIP scenarios.

This document describes the DID number mapping functions offered in the Comdasys Convergence Products. The Comdasys Convergence support Survivability functionalities for Branch Offices. In those scenario it will take over the functionality of a central PBX / Softswitch in case this system has failed or is unavailable due to network problems (e.g. WAN Outages). In those cases the Convergence system will directly handle inbound and outbound calls. The internal numbers are automatically learned by the Convergence so that there is no need to administer any of this in Survivability Mode. The Convergence offers a number of different basic functionalities in order to cover a wide area of scenarios with some basic enhancements to the learned numbers. We will explain those in detail before going into the scenarios that cannot be covered by these basic mappings.

The Comdasys Convergence Products support Call Forwarding in Survivability mode. This works by matching incoming phone calls (incoming means both from local endpoints as well as through a gateway) against a table of configured numbers. If there is a match, the number will be changed to the configured forwarding target. The configured source numbers can be virtual numbers or actual numbers of connected phones. The target has to be a physically registered phone. The Call Forwarding will only be done when in Survivability mode and is therefore also used as an entry point for the Mult Line Hunt Group operation in Survivability mode.

Learn how to create MLHGs and Pickup Groups as fallbacks in Survivability. We are paying special attention to version 4675.x in which this feature is only accessible via the Command Line Interface.