The MultiVOIP SS survivable SIP gateway and server provides affordable distributed networking capabilities to small branch offices of large corporations. It extends the call features and networking benefits of a centralized PBX/SIP server to small branch offices utilizing a mix of SIP-based IP phones, analog phones and fax machines. The MultiVOIP SS gateway also renders local office survivability, in the case of a LAN or WAN failure, by providing local, reliable PSTN trunking.