(Enlarged continuation of part of Question 9/12 studied in 1997-2000)

Type of question

Task oriented designed to lead to new ITU-T Recommendation(s).

Background

Traditionally, the analog and digital telephones were interfacing switched-circuit 64 kbps PCM networks. With the fast growth of IP networks, terminals directly interfacing packet-switched networks (VoIP) are being rapidly introduced. Such IP network edge devices may include gateways specifically designed IP phones, soft phones or other devices connected to the IP based networks and providing telephony service. Since the IP networks will be in many cases interworking with the traditional PSTN and private networks, many of the basic transmission requirements have to be harmonized with specifications for traditional digital terminals. However, due to the unique characteristics of the IP networks including packet loss, delay, etc. new performance specification, as well as appropriate measuring methods, will have to be developed. Also, the VoIP terminals may use other than 64 kbps PCM (G.711) speech algorithms, as well as may provide traditional narrow-band (300-3400 Hz) or wide-band telephony (200-7000 Hz).

Preliminary work has been started in the 1997-2000 Study Period under Question 9/12 resulting in a draft Recommendation P.31x "Voice inside the data path of VoIP terminals and its methods of measurements".

Text of the question

considering

a) that IP terminals and gateways are being currently introduced;

b) that the packet based speech transmission has unique characteristics different from the
traditional switched-circuit networks;

c) that IP terminals and gateways may include active echo control;

d) that IP terminals and gateways may include low-bit rate speech compression algorithms;

e) that IP terminals and gateways may provide narrow band as well as wide band speech;

f) that IP terminals and gateways may include handset, hands-free or headsets,

the following question should be studied:

- What transmission characteristics and measurement methods are needed for IP terminals and gateways ?

NOTE 1 - The work will take into account already existing standards for traditional digital telephone sets and new IP speech terminals, e.g.: ITU-T P.310, P.340, P.342, G.177, TIA/EIA-IS-810, ETSI TR 101 329.

Objectives and schedule

It is anticipated that the study will result in new ITU-T Recommendation(s).

The estimated time frame is one Study Period.

Relationship with other standardization bodies

Relationship will be established with ETSI TYPHON, TIA TR-41 and other organizations involved in similar work.