Checking your Tandberg/Cisco VCS Expressway for hack-attacks from VOIP SIP scanners

A SIP scanner is a tool that scans a VOIP/Video network from the Internet side with the intent of “breaking in” and using the network to place voice/video calls. Today, toll avoidance and toll fraud appear to be the primary motivation (rather than SPIT) – however, one thing is clear: the number of SIP scanner attacks is on the increase. Whilst the attacks that have reached my network  appear mostly to be targetted against badly configured Asterix IP telephony solutions (left with default settings), Cisco/Tandberg VCS Expressway video solutions could be every bit as vulnerable unless correctly configured.