A Stand For The Interoperability Demand
BY ADAM ALTMAN
For a long time now, I've been hearing the words
"protocol" and "standard" used interchangeably in the
Internet telephony industry. While they are similar terms, there is a
major difference that is notable when discussing interoperability, mainly
because a big part of the effort is finding a common standard to
replace or work with the current protocols present. H.323, SIP, MGCP,
Megaco, etc., are protocols -- they govern the format of voice calls over
IP. However, they should not technically be called standards since none of
these are agreed on by everyone involved, not even within each individual
protocol. At most, these protocols could be considered "open"
standards, but this terminology just confuses matters. Likewise,
compression codecs, such as G.711 and G.729 also get confused into the mix
when they should only be considered a part of the overall configuration,
and should therefore not be considered as either a standard or a protocol.
Differentiating all of this may seem like so much "nitpicking,"
but it does show an example of the confusion surrounding interoperability
in general, so making these sorts of distinctions may help clear up some
communication issues.
In my last ConvergeNET recap ("Satisfying
An Urge To Converge," INTERNET TELEPHONY magazine, December
2000), I discussed the four C's for VoIP interoperability: Commitment,
communication, constitution, and convergence. The above example embodies
the importance of the communication aspect. General communication between
companies participating in the fifth installment of ConvergeNET at INTERNET
TELEPHONY Conference & EXPO in Miami from February 7-�9, 2001 was
extremely important even before the actual demonstrations began, as were
the other C's.
We arrived organized with pre-planned diagrams ready and IP addresses
assigned with plenty of time to spare before the show. Heading the H.323
side of ConvergeNET was NetCentrex. With the invaluable help of Science
Dynamics and Quintum Technologies, two zones were set up for the test
network using NetCentrex's gatekeeper and Quintum's Tenor Gateway, which
can act both as a gatekeeper and as a gateway. It was the commitment from
these three companies and the constitution to achieve these
interoperability tasks that drove ConvergeNET on the H.323 side. While
apparent at past ConvergeNETs, this commitment was overwhelmingly evident
at this show. It dictated achieving successful convergence on virtually
every demonstration attempted. I personally thank them, as should anyone
that realizes just how important interoperability is for Internet
telephony. (While on the subject, I would also like to thank Way2Call
Communications (formerly Shelcad) for their commitment to each and every
ConvergeNET thus far.)
Figure 1 shows the H.323 test network for ConvergeNET, which is pretty
self-explanatory. Science Dynamics made VoIP calls with everyone on that
list: NetCentrex, Quintum, Way2Call, ZMM Technologies, and Addatel. I
personally made a few of these VoIP calls and determined that the quality
of the calls was generally agreeable to my somewhat discerning ear.
Science Dynamics was even able to converge using additional equipment from
Quicknet Technologies.
With the exception of Quintum, NetCentrex also registered and converged
with all of these companies. Unfortunately, NetCentrex and Quintum could
not interoperate between their gatekeepers before the EXPO ended. However,
both companies noted how much they learned during the process. I cannot
stress enough about the importance of this education.
Before the show was done, Science Dynamics attempted to link with ASC
Billing Solutions through their RADIUS servers and then make a VoIP call
through NetCentrex's gatekeeper. This type of demonstration was first
advocated by Digiquant (formerly Belle Systems) at the previous
ConvergeNET in San Diego and came closer to being realized in Miami. They
were able to link their RADIUS servers but the configuration for making
the actual VoIP calls could not be correctly determined before the show
ended. However, I certainly commend the attempt and look forward to this
demonstration being successful at the sixth Installment of ConvergeNET at
October's INTERNET TELEPHONY Conference & EXPO in San Diego.
On the SIP front, Ubiquity Software headed the charge and showed many
of these demonstrations through their SIP Center. As depicted in the SIP
diagram, Ubiquity used endpoint equipment from Cisco (both
their IP phone and Komodo Fone), Pingtel, and 3Com as well as their own
SIP user agent and Helmsman Desktop software to connect through the
virtual test bed at www.sipcenter.com
to another endpoint. With the exception of the Cisco IP phone, these VoIP
calls were all successful. For example, a 3Com SIP phone successfully
called both a Komodo Fone and a Pingtel xpressa phone through Ubiquity's
SIP proxy server. Unfortunately, testing could not take place using the Cisco IP phone because the correct power adapter required was not available at the show.
In addition, Ubiquity was also able to converge with Indigo Software in
the traditional ConvergeNET manner. They successfully called each other
from booth to booth across the LAN on the Internet Telephony EXPO Exhibit
Hall floor.
Thus ends another ConvergeNET as we stride closer to attaining
interoperability and a de-facto standard. We are slowly zeroing in on our
goals, and the next installment of ConvergeNET in San Diego should further
attest to that commitment that we initially laid on the table almost a
year and a half ago. As we pave the road towards better communication
while continuing to educate attendees and vendors about interoperability
issues, I wonder when I should attempt to clarify all the acronyms
meandering around the industry. But alas, that's for another time, so for
now, I'm content with taking a "stand" on matters in the realm
of interoperability.
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