It has always been difficult to deploy IP telephony in firewall-protected networks since VoIP protocols were not designed to easily traverse the firewall.

Kerio WinRoute Firewalls supports various VoIP-based hardware or software such as Cisco IP Phone 7960, IP SoftPhone, CallManager, Gatekeeper, SIP Proxy Server, Interactive Voice Response, Cisco Unity Voice Mail, etc.

H.323 and SIP
Kerio's protocol inspection modules help the firewall correctly handle VoIP phone and video communication. Kerio WinRoute Firewall allows all VoIP devices using either H.323 or SIP protocol to be used in the protected network and therefore eliminates the need to publicly expose the VoIP infrastructure to the Internet.

Cisco SCCP
If a company wants to take advantage of VoIP devices in Cisco AVVID environment, Cisco's Skinny Client Control Protocol (SCCP) is used for establishing communication between an IP Phone and Cisco CallManager. The firewall of course needs to recognize it and understand the information passed within these signalling messages.

Kerio WinRoute Firewall automatically detects SCCP protocol and perfoms NAT for address translation between the IP phone and Cisco CallManager. Since Kerio WinRoute Firewall performs dynamic IP address translation, an administrator does not need to manually configure an IP address within NAT for each IP phone.

UPnP support
Universal Plug and Play (UPnP) in Windows enables applications to communicate without additional settings at the firewall. Kerio WinRoute Firewall integrates UPnP technology so that compliant applications such as MSN Messenger can run instantly without hassle.