The Global Dialing Scheme Explained
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: < IAC><CC><OP><EN>
1. The International Access Code (IAC)
Also called the
world gatekeeper prefix. This is defined as 00
2. 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_763.html
3.
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).
4. 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. 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
Egon Verharen
SURFnet
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