VOIP -> Free VOIP gateways

SIPRG (SIP Residential Gateway)

The SIP Residential Gateway (SIPRG) is an open source application based on the Session Initiation Protocol (SIP). The SIPRG is an IP Telephony Gateway that allows a SIP User Agent to make and receive calls between the Public Switched Telephone Network (PSTN) and a SIP-based network such as VOCAL.

The SIPRG was developed with the VOVIDA SIP stack version 1.3.0, and uses a QuickNet LineJACK card for connecting an Analog telephone line. Currently, it supports only a single LineJACK card and is therefore a single-line gateway.

isdnh323

isdn2h323 is a Linux based H.323 - ISDN gateway. At the moment the gateway supports the following features:

• ISDN and H.323 users can initiate a connection.
• The number of simultaneous incoming and outgoing calls is limited by the number of available ISDN channels only.
• H.323 users can specify the ISDN number of the other party.
• The gateway's administrator can assign an ISDN MSN to a H.323 user. This makes it possible for an ISDN user to call a H.323 user directly. The gateway will choose the H.323 user id depending on the called ISDN MSN.
• The gateway discovers an available H.323 gatekeeper and registers with the gatekeeper. It's possible to specify one or more phone prefixes the gateway is responsible for.
• ISDN's touch-tones (DTMF) are translated to H.323's user input messages and vice versa.
• Automatic gain control (AGC)
• Automatic echo compensation (AEC)
• To avoid security problems the gateway offers an option to restrict the IPs allowed to use the gateway for an outgoing ISDN call.
• The status of the lines and the configuration of the gateway are written to a HTML file.
• Errors and other information are logged using Linux's syslog() feature.
• Three H.323 codecs are supported: ALaw, muLaw, and GSM.
• Least Cost Router

PSTNGw

PSTNGw is a very simple PSTN to H.323 gateway program using the OpenH323 library. It allows H.323 clients to make outgoing calls, and incoming calls to be routed to a specific H.323 client.

PSTNGw makes use of PWLib and the OpenH323 stack from Equivalence Ltd Pty.