PSTN to Internet internetworking (IP/IETF) (PINT)
The PINT working group of the Internet Engineering Task Force( IETF) is working on the Web and teleservices that are transmitted from IP networks to the PSTN. This work is described in RFC 2848 as a Proposed Standard.
In order to be able to execute these services, known protocols such as the Session Initiation Protocol( SIP) and the Session Description Protocol( SDP) have been functionally extended and a new protocol, the SSTP protocol, has been developed from them.
With PINT(PSTN to Internet Internetworking), services implemented in an IP network can be merged with the intelligent network( IN) for ISDN and GSM, for example. Thus, a telephone callback from ISDN could be initiated from a web page with a mouse click.