PSTN Internet Notification
charter-ietf-pin-01

Current PSTN/Internet Interfaces (PINT) WG addresses connection
arrangements through which Internet applications can request and enrich
PSTN (Public Switched Telephone Network) telephony services. Some
Interworking services require Notification and requests for services
that come from PSTN/IN. Essentially, these requests will be "mirror
image" of PINT requests. To provide interoperability between PSTN and IP
networks, it  is very important to ensure notification to the IP network
of  the events happening in PSTN. PSTN/IN Call Flow is organized around
actions or collections of actions called Point-In-Call (PIC). Detection
Points (DPs), which are associated with the PICs, operate between the
PICs and can be the basis for Notification Events for Interworking with
IP network. IN furnishes "Network Intelligence" to PSTN. Similarly, it
can be utilized to initiate Notification Events to IP network.

We are proposing new Working Group to be a "mirror image" of the PINT
WG, regarding direction of the requests for service and dealing with 
Notification only. Like PINT, PIN will not deal with IP Telephony,  but 
rather  provide requests for services and Notifications from PSTN/IN to
IP network in order to augment, extend and enrich PSTN. PIN WG would
focus on the PIN Protocol Requirements and Definition of Notification
Processing Language (NPL) - a possible extension to CPL, as well
as defining connections of Services to the IN DPs. PIN protocol is a
specialized protocol used for communication between the  PIN Gateway and
PIN Servers, which may, potentially, be used for communications between
PIN Servers and PIN Clients. NPL will allow to build new Notification
Services and provide means to describe Notification Filters to screen
PSTN events. Notification Filter  example: Notification for an Attempt
to Enter Conference from a predefined number in the hours 9 through 17
only on weekends and holidays. It is quite possible that existing or
under development protocols (i.e. SIP, PIP, MGCP, etc.) are sufficient
to support PIN Services, but that determination is for further study by
the PIN WG.