The Global Dialing Scheme Explained
Egon Verhayen
The Global Dialling Scheme (GDS) is a new numbering plan for
the global
video and voice over IP network test bed, developed by ViDeNet.
It
resembles the international telephone system numbering plan,
with some
exceptions. With the GDS, you can number each participating
videoconferencing endpoint, MCU conference and gateway. GDS provides
easy,
uniform dialling throughout the world.
Each basic number consists of four parts
- The International Access Code (IAC) (also
called the world gatekeeper prefix) This is defined as 00
- A Country Code (CC) This
follows the ITU international access code system. For instance,
the country code for the Netherlands
is 31. See the following PDF document for
country codes: http://www.itu.int/itudoc/itu-t/ob-lists/icc/e164_717.pdf
- An
Organisational Prefix (OP) Many
national research organisations follow
the telephone number system in their
country and use their area code and organisational
telephone exchange prefix.
For instance, SURFnet's OP is 302305.
However, there are other possibilities.
Some organisations use their administration
number or make one
up. National research organisations or
videoconferencing service providers
could instead supply you with an OP,
as was the case with the old ViDeNet
system. In any case, your OP MUST be
unique within a country. If you
don't know your OP, please contact your
videoconferencing service provider,
your national gatekeeper, or the NASM
working group (see below).
- An Endpoint Number (EN) Your EN
can be any number and is decided
by each organisation. However, we recommend
that it be no longer than seven digits. Each endpoint number MUST be
unique within the organisation. Both 305 and 1234567 are
fine examples as
long as they are unique.
The whole numeric number therefore looks like: <IAC><CC><OP><EN>
Examples:
The Megaconference informal test MCU: 00(IAC) 1(CC) 189(OP) 7201234(EN)
Typed into your videoconferencing endpoint, the
number would simply look
like: 0011897201234
The GDS also defines an alphanumeric dialplan
(not used during the
Megaconference game). This part is
equal to the alphanumeric dialplan
of
the old ViDeNet and should be in
the form:
<
station ID>@<fully qualified domain name of the institution>
An
example
is: egon.verharen@surfnet.nl
More information on the GDS and the
Numerical Addressing Space Management
(NASM) working group overseeing
its development can be found
at:
http://www.wvn.ac.uk/support/h323address.htm and
http://www.vide.net/workgroups/nasm/index.shtml
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