Downloading Firmware 
Unzip the files to a folder. Note that the bin files in the zip file will have the same name as the bin files in the installation software that came with your MultiVOIP-SS, so it's recommend to unzip it to a different folder or a subdirectory of this folder. Connect a COM cable from PC to the MultiVOIP-SS command port. In the MultiVOIP-SS v3.09 program group run "Download Firmware", and select the "mvpt1.bin" file that you unzipped. 
Using Fail Over Feature 
The fail over feature uses the Outbound Phonebook's SIP URL field to set where the call will be sent on fail over. If "Use Proxy" is enabled and a valid SIP URL is entered, a call using that outbound phonebook entry from a channel on the MultiVOIP-SS in survivable mode (primary is unreachable) that fails through proxy will be sent to the SIP URL. The SIP URL should be in the user@ipaddress format. The SIP URL can point to another SIP device or to MultiVOIP-SS. If the SIP URL points back to the MultiVOIP-SS, there should be a inbound phonebook entry with the "user" (of the user@ipaddress in SIP URL) number as the "Remove Prefix" so the MultiVOIP-SS will accept the call.