Freeswitch, an open-source softswitch started earlier this year, leverages open-source software libraries and has recently added support for Google Talk. The codebase now includes Jingle (Jabber XMPP Voice) support with the addition of libDingaLing and mod_dingaling libraries. Jingle is an XMPP based protocol used by GoogleTalk. Using FreeSWITCH you can gateway GoogleTalk to SIP, H.323, or even the Asterisk IAX2 protocol. They also support Sangoma PRI cards and they recently announced support for secure RTP communication.

The libDingaLing library is currently considered to be in Alpha stage, but has been compiled and tested on many computer platforms including Windows XP, Solaris, Linux and MacOS X. The new endpoint module appropriately named "mod_dingaling" couples FreeSWITCH to libDingaLing and allows both inbound and outbound communication thus enabling GoogleTalk to gateway to the PSTN or to other VoIP protocols such as SIP or H.323. Looks like "Google Out" PSTN capability won't have to wait for Google to offer it themselves after all!