SIP

BaseVoice

basevoice.com

Commercial software development company that produces PBX, router, proxy and application server software.

158 visits Dec 24, 2025 Details

Brekeke Software

brekeke.com

Products for small to medium sized offices and a server database.

93 visits Mar 31, 2025 Details

eSMS.com

esms.com

Provides UK phone numbers which forward calls to SIP.

208 visits Nov 27, 2025 Details

Free IP Call

freeipcall.com

A proxy service provider with information in English and French.

196 visits Dec 16, 2024 Details

Interactive Intelligence, Inc.

inin.com

Developers of a proxy server. Site contains downloads, documentation and a forum.

281 visits Apr 11, 2024 Details

LignUp Corp

lignup.com

Applications developer. Products include software PBX's for enterprise and service providers.

177 visits Aug 21, 2025 Details

Ninetel USA

ninetelusa.com

A USA based proxy service provider and supplier of hardware phones and routers. Site contains call rates and service details.

276 visits Apr 21, 2023 Details

OpenSER

openser.org

A branch of the SIP Express Router project, offering an open-source SIP server.

437 visits Mar 24, 2025 Details

Parrish Systems

parrishsys.com

Sells off the shelf code and provides a software consultancy service.

9 visits Sep 23, 2024 Details

PC Phone Review

pcphonereview.com

News and reviews of hardware, software and service providers in the United States.

314 visits Oct 21, 2025 Details

PROTOS Test Suite

ee.oulu.fi

A test-suite to find vulnerabilities in protocol software.

172 visits Feb 5, 2025 Details

pulver.com

A collection of information on the protocol. Contains news, reports and an IP telephony job noticeboard.

413 visits Apr 19, 2026 Details

Secure SIP Client

securesipclient.com

An RFC3261 client running on Win32 and WinCE PDAs supporting voice, video, sRTP and signaling security by TLS.

341 visits Mar 2, 2026 Details

Session Initiation Protocol (SIP)

cs.columbia.edu

FAQs, background materials and lists of current work in this field.

245 visits Feb 25, 2026 Details

SIP Compose Group

compose.labri.fr

A working group experimenting and documenting the protocol. Contains various internet technical resources.

300 visits Jun 8, 2025 Details

SIP Forum

sipforum.org

A membership based forum. Also contains a news board.

167 visits Dec 5, 2024 Details

SIP Made Easy

geocities.com

An introductory tutorial talks about protocol functions, components, message types, how it works and where it is applied.

484 visits Jul 7, 2025 Details

SIP Wiki

toyz.org

Wiki based resource containing information and links.

241 visits Aug 14, 2024 Details

SIP411 Directory Services

sip411.com

A Yellow Pages style directory of SIP addresses.

201 visits Sep 6, 2025 Details

Sipcall

sipcall.co.uk

A UK based service provider. Also contains hardware related links and protocol white-papers.

299 visits Jul 4, 2024 Details

Category Info