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Mixed Media Standards

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VoicenData Bureau
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The Emergence of a

Market

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Over the

past few years, the trade press and voice and data product vendors have heralded the

arrival of a new era of communications. Their articles and brochures depicted a world in

which real-time mixed media communications on the corporate
face="Times New Roman">Local Area Network (LAN) becomes a widely used, business-useful

capability. With the click of a button, end users in this new era would be able to

communicate robustly with the richness of mixed media (voice, video, and data application

sharing).

Corporations would begin to migrate all

corporate communications onto a single network reducing both cost and complexity.

Real-time and near real-time calling would join file server, E-mail server, and other

traditional LAN traffic on a single, merged network.

Collaboration using mixed media across

geographically dispersed locations would increase productivity and lower travel costs.

Telecommuting would become less isolating and more productive. The possibilities seemed to

be almost endless.

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Many of those heralding this new arrival

predicted that the market for solutions would grow quickly. Others were more cautious,

noting there was really not a standard defining the interoperation of this type of

offering from different manufacturers.

Many vendors built products that used

proprietary call setup signaling or proprietary voice, video, and/or application sharing

protocols. To their credit, many of these offerings did provide a viable mixed media

conferencing service on customers’ data networks. Unfortunately, these products did

not interoperate with one another.

Potential customers, having experienced or

witnessed the headaches associated with trying to make different vendors’ data

products interoperate, were hesitant to buy these proprietary implementations. In the end,

those who were cautious were in much bigger numbers. As a result, the market developed

slowly.

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Standards:

Essential to Market Growth

SIZE="4">



Since 1990, momentum surrounding development for mixed

media standards has grown. Prospective purchasers require confidence of full mixed media

interoperability to make the required business investment.
COLOR="#000000" face="Times New Roman">





The players in the industry realized the

need for another approach to create this new market and generate revenue from their new

products in a more timely way. Seeking a cooperative way to leverage this market, many of

the vendors came together under the auspices of the International Telecommunications Union

(ITU), a United Nations agency based in Geneva, Switzerland, to formalize standards for

interoperation between their LAN-based mixed media communications products.
SIZE="2">

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In 1990, the ITU sanctioned the H.320

suite of standards for audio compression and communications standards. It was now possible

to link narrow-band visual telephony and terminal equipment from different vendors on the

same conference. Effective deployment of cameras enabled users to see one another and

"still shots" of data and documents. H.320 used fractional T1, switched 56, and

ISDN networks.

Early deployments of H.320 were expensive,

which limited market acceptance. Some vendors produced an alternative that worked over

regular telephone lines (POTS) to gain market entry. This less-costly alternative had some

success, but it was limited by its low, irregular transmission quality, limited feature

set, and lack of interoperability. Mixed media was not yet ready for business-critical

deployment.

The H.320 standards resulted in

significant, ground-breaking developments for ISDN-based collaboration. They paved the way

for subsequent standards (e.g., T.120, below) that further enriched mixed media

communications’ potential. LAN-based collaborations should similarly benefit from the

H.320 standards suite.

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Later, the T.120 recommendation

established data protocols for multimedia conferencing in multi-vendor, data-only

conferences. It also added document sharing to any H.32X video- conference. This allowed

users to interactively collaborate in real-time by sharing applications. Coupled with the

H.320 standards, interactivity became more meaningful.

Early deployments of the more robust mixed

media capabilities were limited to point-to-point applications. This clearly limits its

usefulness to business, which often needs entire workgroup participation and/or

involvement of additional subject matter expertise on an ad hoc basis. Hence,

vendors today are turning away from point-to-point to concentrate more on platform

deployment of robust mixed media communications. This represents the market for greatest

business usefulness and long-term growth.

Refining Standards

Further

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Since

1990, momentum surrounding development for mixed media standards has grown. More than

ever, prospective purchasers require confidence of full mixed media interoperability to

make the required business investment. Vendors need to produce standards-compliant

services to meet that need and maximize market opportunities. Standards-setting efforts

support both concerns. The result of these efforts is a standard known as H.323, for

video-enabled telephony
systems and equipment

for local area networks which provide a non-guaranteed quality of service. It forms the

basis for ensuring that the LAN-based offerings built by manufacturers are interoperable.

H.323 has rapidly gained wide acceptance within the industry as the leading standards

platform upon which to build LAN-based mixed media products. Among other things, the H.323

standard specifies:

  • a protocol for controlling

    access to and use of LAN for mixed media calling. This component is known as Registration,

    Admission Control, and Status (RACS).

  • all the signaling required to

    set up calls on non-guaranteed quality of service LANs. This component is based on the

    ISDN Q.931 protocol, known as H.225 Call Control.

  • the required and optional

    encoding and synchronization formats for the voice, video, and data streams to be

    communicated between participants, and

  • a mechanism for negotiating

    which encoding formats will be used for voice, video, and data exchange and for setting up

    and tearing down these connections, known as H.245.

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Since the ratification of H.323 Issue 1 in

May 1996, the vast majority of the players, large and small, in the mixed media

conferencing business have been building products that conform to H.323 standard. To

further ensure interoperability between their products, they joined together and formed an

interoperability testing effort under the umbrella of the Internet Engineering Task Force

(IETF). It is to this forum that vendors bring their evolving products and test them with

one another. Vendors now meet regularly to interconnect their products and run through a

series of tests to ensure that the products they offer to customers work well together.

Lucent Technologies leads the IETF Study

Group 15 work in development and refinement of standards in transport networks, switching

and transmission systems, and equipment (including the relevant signal processing

elements). Lucent also leads the IETF Study Group 16’s work in mixed media service

definition and mixed media systems (including the associated terminals’ modems,

protocols, and signal processing).

Extending

H.323 Capabilities

Seeing the need for bridging the worlds of

voice, data, and video, Lucent introduced the MultiMedia Communications eXchange (MMCX).

The MMCX extends easy-to-use business telephony calling features to real-time voice, data,

and video collaboration sessions over local and wide area networks. As the first

H.323-enabled server in the market, the MMCX allows any standards-compliant endpoint to

serve as a practical business tool, enabling users to assign a telephone number to their

desktop, conference up to six parties for a mixed media session and route calls to voice

mail or covering extensions.

In addition, the MMCX enables any H.323

standards-compliant endpoint to take advantage of the following telephony-enabled

features:

  • the ability to make telephone

    calls out into the public telephone network,

  • use of the public telephone

    network as a wide area network to call between server communities when high quality of

    service is required,

  • use of server capabilities to

    reduce the bandwidth used across these distances to reduce the cost of operation between

    the server communities, and

  • the ability to use the Lucent

    Technologies DEFINITY(r) ECS advanced features to which the MMCX provides access to

    "traditional PBX" features, such as: call detail records, class of service, and

    class of restriction, least-cost routing, hunt group access, etc.

  • Lucent Technologies extends

    existing standards to provide features and value-adds that are not yet supported by the

    H.323 standard. This allows the MMCX to be fully interoperable with other vendors’

    products while giving the flexibility to bring customers added features and functionality.

    Of course, Lucent continues its work within the standards body to add these extensions to

    H.323 where it makes sense to do so.

As the H.323 standard evolves and products

that allow use of LANs for real and near-real time communication become commonplace, look

to Lucent Technologies to: continue driving the standards so that they allow development

of new, more powerful features in H.323 products, develop H.323-based products that

provide the level of business-usefulness the market expects from Lucent Technologies, and

add value to the H.323-based offerings of other industry players.

As a driving force for standards, Lucent

Technologies is confident that mixed media communications will become a reality for the

industry as a whole. Business users will finally be able to realize the promise of the

merged voice and datanetworks.

Extracted from a white

paper on mixed media standards published



by Lucent Technologies in June 1997.

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