Open Standards - Snom 4S Administrator's Manual

[
S N O M
VoIP industry under a common standard,and move the world of telephony
into the computer industry, using most of the methods known from ISDN.
Seen however from today's perspective, the resulting technology was too
complex, so products based on this technology did not work well together.
The late introduction of "supplementary services" (H.450.x) not only
introduced another level of complexity, but was also simply too late.
By the late 90s, the Session Initial Protocol (SIP) had been
proposed (RFC 2543
built upon the same principles used by http and email. Moreover, it has
found an enthusiastic community of researchers and developers who like
the idea of applying Internet technology to real time communications.
More and more applications are being put into SIP, telephony being just
one of them.
So far more than 200 drafts have been proposed for extending
the SIP protocol. All kinds of solutions are being addressed in these
documents, and the highly dynamic field of this new real time
communication technology is resulting in evolutionary pressure to find the
best common denominator. RFC3261 can be seen as the core or a series
of new RFC that define the rules of the new telephony industry just like
DNS, HTTP and other standards already did for the world wide web.
Most of the "big players" have jumped on the SIP train. Microsoft
Messenger 4.7 is based on SIP and Cisco Systems offers SIP extensions
to most of its products. International organizations like ETSI host SIP
interoperability events, and next generation mobile technology will be
integrated with, if not based on, SIP (see http://www.3gpp.org for more
details).
Other protocols like MEGACO (H.248) seem to play only a role
in niches. The "Skinny" protocol proposed by Cisco Systems can only be
used by Cisco proprietary products which limits the choice significantly.
Other vendors like Siemens also extend their PBX solutions by more
or less propretary solutions. We believe that can only be a temporary
solution, as customers do not want to be dependant upon a single supplier
for their most critical systems.

Open Standards

Open standards define the rules of the game. Interoperability
allows customers to choose between the products of different vendors and
12 • VoIP Protocol
4 S P / R
R O X Y E G I S T R A R
). SIP follows the paradigms of the Internet, and is
1
M ]
A N U A L