Watching How Sausages Are Being Made
We believe the style in which SIP has been developed is another feature, equal
in importance to what gets actually written in the standard.
■■ Open—The development of SIP in the IETF mirrors many other devel-
opments that have contributed to the success of the Internet. The SIP
protocol development is a completely open process, where everyone
(from anywhere) can follow the online postings and discussions, and
make technical contributions. There are no fees for participating, except
a moderate attendance fee to cover the cost of IETF meeting logistics.
Nothing in SIP involves intellectual property rights claimed by organi-
zations or individuals, and open source code and testing facilities are
available on the Internet, as well as the ample technical information.
■■ Contributors—Technical discussions conducted by e-mail and concluded
in face-to-face IETF meetings are moderated by the some of most recog-
nized academics and industry experts in the field, regardless of the size
or origin of the organization they are from. The authors of the base SIP
protocol standard and of extensions to SIP are clearly identified and can
be contacted by anyone for discussions regarding their contributions.
The SIP discussion mail is mostly populated by hands-on developers
exchanging notes on issues with running code on their machines.
■■ Surge of creativity—The completely open and collaborative environment
for SIP has generated the largest number of technical contributions
experienced in any area of Internet technology, from many individuals,
working for various organizations, small and large, from all over the
world. The top problem facing the chairs of the IETF SIP working group
(WG) is managing the very large number of technical contributions.
Various subgroups have been created within the SIP WG to cope with
this problem.
■■ The SIP standard is based on running code—Contributors to the SIP WG
bring to the table experience from building SIP products and SIP ser-
vices. Numerous interoperability tests are conducted on a regular basis
as SIP matures, so as to prove features before declaring them part of the
standard.The abundance of SIP implementations across the industry is the result of
this working style in the development of SIP.
SIP Overview 101