Due to the fact, that the Comdasys proxy is the primary proxy for the phones and the Lotus Sametime Unified Telephony is the secondary proxy, all calls from the phones are signaled via the Comdasys. The Comdasys will recognize a WAN failure and forward calls automatically via the PSTN. Once connectivity to the Lotus Sametime Unified Telephony is re-established, the proxy forwards the requests to the Lotus Sametime Unified Telephony again as normal.
In case of a WAN failure:
Comdasys proxy will forward all branch external calls via the MTX GW to the target destination.
The limited Comdasys and local phone feature set is available for all branch office users.
Calls from the branch office to the headquarter are routed via the PSTN.
Calls from the Headquarter to the branch office are rerouted via the PSTN.
Calls to the PSTN are routed by the proxy through the Mediatrix 1400 to the locally connected trunks. Similarly, incoming calls on these trunks are forwarded to the respective endpoints through the local SIP proxy. Once the Lotus Sametime Unified Telephony takes over again, PSTN calls are routed through the WAN to the central gateway at headquarters.
Parent topic: Survivability Overview
Survivable Branch Office using Mediatrix with Comdasys proxy server