SIP Interoperability Test Event FAQ
- What is a SIP interoperability test event?
- A SIP interoperability test event is a meeting of developers of SIP
implementations. At the SIP interoperability test event, groups of
implementors test their implementations for interoperability with other
groups. A interoperability test event usually lasts about three days
and takes place roughly every four months (April, August, December). It
has been proposed to extend the interoperability test event duration to
four or five days.
"The interoperability test event is for non-competitve, friendly
testing of possibly incomplete code - not a certification environment or
anything of the sort. It is meant as someplace people can come to, and
test their code at, without feeling the pressure of success. There
should be no business repercussions from the results of the bakeoff."
- Who can attend SIP interoperability test events?
- Only implementors of SIP-related software and hardware are allowed
to attend the interoperability test event. Groups must have an existing
implementation, rather than just a plan to implement SIP. Journalists,
sales & marketing staff and recruiters are explicitly not
- Is there a limit on the number of people that can attend?
- To allow reasonable communication and coordination between
participants, each organization is limited to two (2) participants per
product (distinct software or hardware implementation, with distinct SIP
code base). Exceptions can be made if space is available.
- Are there presentations or talks at the interoperability test event?
- No, the interoperability test event is not a training event, trade
show or industry conference. There are no presentations or panel
discussions, just groups testing equipment and software.
- What kind of equipment can be tested?
- SIP user agents, proxy servers, software, phones, gateways, voice
mail systems, protocol testers, ... Generally, both SIP and, to a
lesser extent, RTP functionality is tested.
- Is there a minimum requirement for participating?
- There is no entrance exam and early implementations are welcome to
participate. However, other groups may not appreciate being "used" to
debug basic program functionality with you. Thus, it is generally
expected that you have done your "homework" and tested basic call setup
and, preferably, have a parser robust enough to handle most of the "torture tests" and test
- Where have SIP interoperability test events been held?
||Columbia University, New York, NY
||April 8-9, 1999
||Pulver.com, Melville, NY
||August 5-6, 1999
||Ericsson, Richardson, TX
||December 6-8, 1999
||31 teams (26 companies)
||3Com, Schaumburg (Chicago), Illinois
||April 17-19, 2000
||46 teams (36 companies)
||pulver.com, Melville, New York
||August 8-10, 2000
||50 teams (44 companies)
||Sylantro, Santa Clara, CA
||December 5-8, 2000
||March 25-30, 2001
||Ubiquity, Cardiff, UK
||August 13-17, 2001
||Nuera, San Diego convention center, CA
||December 2-7, 2001
||Nextone, Washington, DC
- Is there an NDA to sign?
- No. SIP interoperability test events operate on mutual trust and
cooperation. We expect attendees not to reveal product features or bugs
discovered during testing. The results of the interoperability test
event are not published in identifiable detail, but a press release is
issued identifying the participating organizations. Thus, if the
existence of your work is secret, you are probably ill-advised to attend
the interoperability test event.
- Can my company release a press release after the interoperability
test event or mention the interoperability test event in marketing
- Yes, of course. However, please avoid the following:
- implying in any way that the interoperability test event certifies
- using the classification of implementations (basic,
intermediate, advanced) in any public information, including press
releases and product literature;
- implying that your implementation was proven to be better
than others, including that your implementation was the only one having
certain features; thus, avoid terms like "only one", "best", "top 10", etc.
- specifying which companies your product interoperated with, i.e.,
don't say something like "we successfully interoperated with A, B and
You are welcome to say things about the number of companies
participating in the interoperability test event, name the products that
you tested, make general comments about the state of the SIP "industry"
or your general experience at the interoperability test event, etc. We
would like to avoid any impression that the SIP interoperability test
event is anything other than a closed-door technical event. We
would also like to be able to maintain a gentleman's agreement on these
issues, without having to issue formal guidelines.
- Where are interoperability test events held?
- Organizations volunteer to host the interoperability test event
either in their own facilities or in a nearby hotel, depending on
- Where are SIP interoperability test events announced? Is there a
- SIP interoperability test events are announced on the SIP website, the SIP interoperability test event
pages and the SIP mailing list. There is also a specialized mailing
list for SIP implementors, email@example.com
(subscribe by sending email to firstname.lastname@example.org, with
subscribe sip-implementors foo@bar in the message body.)
- What happens at the SIP interoperability test event?
- Generally, interoperability test event participants alternate
between two types of interoperability tests, namely pair-wise testing
and larger demos. The hosts or other volunteers gather implementation
information ahead of time, classifying
implementations into UAs and proxies, with basic, intermediate and
advanced ranking in each category. Depending on the interoperability
test event, participants either find other implementations with similar
capabilities or pairings are assigned ahead of time.
In addition, a number of demo scenarios are set up where larger
groups of organizations get together to test more advanced scenarios.
There's often also a general discussion of any problems
related to the SIP specification which may then be collected for
presentation to the SIP WG.
- Is there a interoperability test event winner?
- Yes, hopefully every attendee wins by improving the robustness of
their implementation. Typically, bugs are fixed even during the
interoperability test event. There is no competition for the best
implementation. However, if you expect other financial rewards, you are
advised to contact the real
interoperability test event instead.
- Who is responsible for SIP interoperability test events?
- Informally, Henning Schulzrinne coordinates scheduling and venue.
Hosts are responsible for local arrangements. A technical program committee handles the technical
aspects such as interoperability tests.
- How much does it cost to attend the interoperability test event?
- Hosts are free to charge a fee to recover their direct costs (such
as food and off-site room rental costs); corporate hosts for
interoperability test events 3 and 4 have not charged attendees, while
earlier hosts charged about $100/attendee. It is a tradition that
attendees from not-for-profit organizations are admitted for free. SIP
interoperability test events are not intended to generate profit for the
host; it is expected that hosts provide staff resources without charge.
- Do I need to bring my own computer equipment?
- Yes, only 10/100 Mb/s Ethernet connectivity (at least one port per
attendee) and power will be provided. Hosts will provide both static IP
addresses and DHCP. Sometimes, hosts can provide other networking
facilities, such as T1, but that requires early coordination with the
Other things that you may want to bring along:
- Wireless cards (enough supply for all). Usually the bakeoff host
provides the base station.
- Power strips.
- Extension cords.
- One Ethernet hub/switch for each product and a spare - make sure to
include their power cord and test them prior to packing;
- 10 to 12 Ethernet cables (some of them should be 20-30 feet long);
- Power (plug) converters (110 V - 220 V) for events outside of U.S -
unless you're sure that your hubs can handle 220 V;
- SIP phones (if applicable)
by Henning Schulzrinne