Telecommunication Standardization  Sector                       APC-1264
Original: English

Experts Group for Video Coding  		       September 11-18, 1997
And Systems in ATM and Other 		         	      Sun River, Oregon
Network Environments

STUDY GROUP 16
CONTRIBUTION

Source:	Ascend Communications, Inc.

Contact:	Dale L. Skran
		email:	dskran@ascend.com
		voice:	+1 (732) 450 1635
		fax:		+1 (732) 450 1611

Date: August 16, 1997

TITLE:  More Accurate Call Information in the Direct Call Model

PURPOSE: For action

STATUS: DRAFT

Problem

In the direct call model, it is unclear when the Gatekeeper should start call accounting for a call.  The ARQ is too early since the call is not yet established.  Since in many cases accounting is done in units of seconds, even a small extra amount of time will add up to a lot of money over many calls.  Call termination is well known via the mandatory DRQ, so this is not an area of difficulty.

Proposal

Add to H.323 a new section 8.1.10 “Confirmation of Connect” containing the following text:

The H.323 Version 2 terminal(endpoint or gateway) that is registered with a Gatekeeper and using the direct call model shall send the GK an unsolicited IRR whenever it sends or receives a CONNECT message.  This IRR message contains
a single perCallInfo element for the newly active call. This message whether IRRs are requested in the ARQ or not. This message is assumed to indicate a call state of “connect.”

We may also wish to consider adding a “call state” field to perCallInfo, but this is not essential. 

Add to H.225.0 the following text in section 7.15:

The IRQ is sent from a gatekeeper to a terminal requesting status information in the form of an IRR.  The IRR may be also be sent by the terminal at an interval specified in the ACF message without the receipt of an IRQ from the gatekeeper. H.225.0 Version 2 requires IRR to be sent on reception/sending of CONNECT whether the irrFrequency is present in the ACF or not.  This message should not be confused with the Q.931 STATUS message.

Add to H.225.0 the following text in section 7.11:

irrFrequency - the frequency, in seconds, that the endpoint shall send IRRs to the gatekeeper while on a call, including while on hold.  If not present, the endpoint does not send IRRs while active on a call, and it is expected that the gatekeeper will poll the endpoint. H.225.0 Version 2 requires IRR to be sent on reception/sending of CONNECT whether the irrFrequency is present in the ACF or not.