- Heidi Bersin, Senior Vice President, Corporate
Marketing and Communications, Clarent Corporation
- Mark Miller, Director, Data Networks and IP
- Jim Machi, Director of Marketing, DM3
Products, Dialogic Corp.
- Jeff Sieloff, Vice President of Marketing, IP and
Fax Technologies Division, Brooktrout Technology
- Sean Parham, Director, Internet Products
Operation, Internet and Networking Group, Motorola
Heidi Bersin, Senior Vice President, Corporate Marketing and
Communications, Clarent Corporation
One of the biggest challenges for the industry is to achieve complete service
interoperability. Open protocols provide the foundation for this, but service providers'
needs tend to go beyond what is specified in the open protocols. Vendors must work
together, with close involvement by their service provider customers, building service
profile enhancements on top of the open protocols so that the service providers' total
service requirements can be met. Over time, more and more of these service profiles will
be added to industry standard protocols.
A second major challenge is the evolution and merger of today's open protocol standards
into a set of complementary protocols. Multi-protocols will exist simply because of the
telecommunications and data communications worlds that IP telephony is bridging - but they
should not compete. This evolution should bring together the best aspects of standards
that have been specified to date. The maturity of standards like H.323, MGCP, and SIP are
helping achieve this goal. Standard bodies like ITU and IETF and industry groups like
Cable Labs are playing an important role in driving collaboration and the evolution and
improvement of the protocols that have been specified to date. The most important drivers
of these standards, though, are the service provider customers who will be implementing
the interoperable technology in their networks, and whose needs for scalability and
reliability are paramount.
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Mark Miller, Director, Data Networks and IP Services, Ericsson
Complete interoperability between different vendors' gateways and gatekeepers is the
largest challenge to date. Many gateway vendors have come out with H.323 gateways and
gatekeepers, however, that does not necessarily mean that they can talk to each other.
True interoperability among different vendors' H.323 gateways and gatekeepers is still
lacking. There is a tremendous amount of publicity surrounding interoperability in which
vendors are claiming to have it, but it is not true integration of disparate networks.
There is still a tremendous amount of debate as far as which standard should be
implemented - SIP, H.323, MGCP, etc. This will be the next major interoperability
challenge, getting different protocols to talk to each other. Many people are quick to
point out the H.323 shortcomings, but it is currently the most developed standard the
industry has to date.
There are several ways to address the interoperability issues. One way to address this
is to implement a border element, which would convert the proprietary protocol to the
protocol of the networked system. Ericsson is currently developing a border element for
4th quarter deployment. Another way to help facilitate interoperability is through
industry intiatives such as iNOW! and cooperation among different standard bodies.
Ericsson sits on all the major standards bodies to insure that interoperability will be
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Jim Machi, Director of Marketing, DM3 Products, Dialogic Corp.�
The largest challenge for vendors right now is overcoming apathy. I say this because
the market demand is simply for delivery of a "marketing" claim of
interoperability, not true engineering interoperability. In our estimate, about 97 percent
of deployed gateways are connected to another gateway of the same type at the other end.
What vendors need is a "compelling event" from the Internet telephony customers
to change this. Up until now, vendors have been able to claim H.323 compliance for
example, yet interoperability between those who truly are H.323 compliant and those who
are partially H.323 compliant is not fully demonstrated. So, unless the customers demand
full compliance from vendors, it will be slow to arrive. The iNOW! initiative, launched by
ITXC and then handed off to IMTC, has taken the charge of establishing an interoperability
agreement and is leading the industry to overcome this challenge.
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Jeff Sieloff, Vice President of Marketing, IP and Fax
Technologies Division, Brooktrout Technology
The largest interoperability challenge for Internet telephony vendors stem from the
lack of well established and accepted interoperability standards. New protocols, such as
MGCP and SIP, are challenging H.323 with the promise of increased scalability and
efficiency for new and different types of applications. This response to improve
performance fuels the co-existence of multiple protocols within the industry. But many of
these standards are relatively new. Their technical definitions, the types of applications
they were designed for, and their future are in question.
Vendors are faced with building their solutions based on standards that may not come to
fruition. To survive, vendors must be prepared to adopt upcoming standards quickly by
building their solutions on flexible architectures, or otherwise risk that a new standard
may give others a competitive edge.
Brooktrout understands the evolution of standards through its leadership in
establishing fax interoperability standards, such as T.38. Hence, we provide a flexible IP
telephony development platform capable of supporting H.323 and other new network protocols
the vendor chooses to drop in. The flexibility and speed to which a vendor can adapt can
differentiate who leads the race; thus we place special importance in offering a flexible
environment for rapid development to give the vendor the cutting edge.
Vendors who invest in the architectures that allow them to closely follow the evolution
of interoperability standards will be well positioned to exploit the unexpected turns of
the industry and emerge profitable in the long run.
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Sean Parham, Director, Internet Products Operation, Internet and
Networking Group, Motorola
In the VoIP industry, two areas can define interoperability challenges, maturity of
current standards for voice gateways and gatekeepers, and true interoperability between
vendors' gateways and gatekeepers. Today, the standards that define how vendors handle
gatekeeper support, call setup, and call tear-down are H.323 version 1, H.323 version 2,
SGCP, and MGCP. These standards are relatively new and some are still being proposed. The
challenge is getting the level of service that ITSPs and CLECs need to provide toll
quality to their customers using these new standards.
With the challenges of using new standards to provide toll quality voice services over
an IP network, VoIP vendors face an additional interoperability challenge with gateways
interoperating with gatekeepers. Today, the VoIP market supports a number of different
gateways and gatekeepers from many different vendors. Can these different gateways all
interoperate with the different gatekeepers available today? The short answer is no.
Problems arise when codecs are incompatible and vendors' H.323 implementations do not
implement the complete spec. To help vendors in their decision on which gateway and
gatekeeper have a high interoperability rating, the ETSI created Project TIPHON
(Telecommunications and Internet Protocol Harmonization over Networks) as a forum for
interoperability testing. This project is one way vendors can resolve the challenge of
gateway to gatekeeper interoperability.
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