SIP (Session Initiation Protocol) is a protocol for creating and terminating various media stream sessions over an IP network. It is for example used for Internet telephone calls and distribution of video streams.
SIP takes care of the initiation, modification and termination of a session with one or more participants. The protocol makes it possible for the participants to agree on what media types they should share. You can find more information about SIP in appendix D, More about SIP, and in RFC 3261.
You find examples on how to configure your Ingate Firewall for SIP in chapter 7, How to configure SIP,.
The SIP module in the Ingate Firewall handles SIP requests for users who have registered on the firewall itself or a machine connected to the firewall (see also Registrar and Users). The module forwards the request through the firewall, which enables users behind different network interfaces to make contact. The SIP module controls the firewall rules to temporarily let through the media streams that the users agree on, on their assigned port.
You must enter a DNS server and a Default gateway on the Basic Configuration page to make the SIP module work satisfactorily.
To enable the SIP function of the firewall, you must at least configure on the Basic and Filtering pages.
If the firewall should act as SIP server or proxy for devices on the other side of a VPN tunnel, you must add the firewall's outside IP address to the local side of the IPsec Tunnels of the VPN connection.
The SIP functions consist of two main parts; a SIP proxy and a SIP registrar. The SIP proxy forwards SIP requests for communication of various kind. The SIP registrar registers SIP users to keep track of where they are.