Background and justification
As work on interoperability in the GII demonstrated, the topic of
interoperability has several aspects. Three of these may logically be addressed
within the context of Mediacom 2004 activity:
- interoperability of services, to the extent that they contain
equivalent functional elements. For example, the service of "multimedia
call transfer" should be fully interoperable with "call
transfer" in the legacy telephone network in the degenerate case of an
audio-only call;
- interoperability of multimedia systems with each other and with the
legacy telecommunications network, to the extent to which they provide
equivalent services;
- measures to enhance interoperability of different implementations of
the same multimedia system or service.
Other bodies besides ITU-T are developing standards relating to multimedia
systems and services. To the extent that the market demands it, methods of
interoperation between ITU-T-developed and other standards must be themselves
standardized. It is desirable that this work be assigned to a common Question.
Study items
This Question shall have the following responsibilities:
- coordinating with the Question on Multimedia Applications and
Services to ensure that the definition of multimedia services and of the
services to be provided by new multimedia systems preserves as much
consistency as possible with corresponding elements of the services provided
by existing multimedia systems and the legacy telephone network;
- standardizing the means for interworking between different multimedia
systems and between such systems and the legacy telephone network, through
additions to Recommendation H.246 and other Recommendations as necessary.
Question D/16 has primary and residual responsibility for Recommendation
H.246, but may delegate the development of sections of Recommendations
dealing with their respective systems to individual questions;
- influencing the development of signalling protocols to further the
objective of multimedia service interworking across different systems and
networks;
- coordinating with the Question on Multimedia Architecture to ensure
that the architectural framework minimizes the effort required to achieve
system interoperability;
- investigating methods and developing tools for improving the
prospects of interoperability between different implementations of the same
multimedia system or service, by means such as the generation of conformance
statements or the creation of reference code in the period between
determination and decision.
Specific task objectives with expected time-frame of completion
- Completion of work on interworking between H.323 and H.320, taking into
account the possibility of MCU decomposition: late 2001. This task has a
dependency on the architectural work item in Question B/16 on review of the
H.245 architecture.
- Completion of proposals for improving the interoperability of different
implementations of systems and services developed under Mediacom 2004: late
2001.
- Implementation of these proposals: 2002.
Relationships
- Work on multimedia systems and services in other Questions of this
Study Group, Study Groups 8 and 9, and ITU-R.
- Study Groups 2 and 11, for service definitions.
- Study Group 11, for signalling.
- Related groups in the IETF (particularly including the IPTEL, SIP,
SIGTRAN and MEGACO Working Groups).
- IMTC, for interoperability testing.
- ISO SC 29 MPEG.
- ETSI TIPHON.
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