already, the open source jabber/jingle program, jabbin, available for linux, windows, and mac, allows one to use jingle-based voip on any jabber server, not just google’s (google talk is just google’s own implementation of jabber, thus it is standards based and compatible with any other open jabber servers out there).

what we have here, then, is (finally!) a bonafide potential replacement for the pstn. SIP (session initiation protocol), for all its merits, is known of as having firewall problems that non-technical people often don’t have the patience to figure out how to fix. skype has been popular, but is proprietary; certainly not a realistic long-term standards-based solution to pervasive decentralized voip.

what jingle offers is the existing support and infrastructure of jabber, along with a big brand name (google), and a simpler (relative to SIP) xml-based spec, as well as good firewall tolerance.

my prediction? SIP and other protocols will go mostly by the wayside within this decade, at the hands of jingle.