From Seo Wiki - Search Engine Optimization and Programming Languages
MySIPSwitch is an experimental stateful SIP Proxy server sponsored by Blue Face to allow the use of multiple supplier SIP accounts from a single SIP login. It basically means that you can use many SIP accounts with a single piece of hardware (IP Phone, ATA or softphone).
The service is based on a dial plan (written either in Asterisk-like syntax or in Ruby). This dial plan allows routing of inbound and outbound calls depending on the parameters you want : call prefeix, time of the day, availability... You can fork an incoming call to various end points, you can forward the call to a second or third end point if the first ones are not responding, you can block calls, you can create a speed dial directory (for instance if you press *1 or *2 ..., it automatically dials, the number you specified ...)... On top of these call management features you have various debugging tools that allow playing with and testing the service.
MySIPSwitch also allows the handling of SIP phone calls from web browsers: hangup, transfer, forward, hold and resume. It is possible to take an incoming call from one provider and forward it onto another provider without having to have a device registered. This makes it possible to receive a call without the need for a VoIP device at all. more info about that point
MySIPSwitch has a user discussion forum allowing developers to improve it according to the feedback from users.  The development language is C#, the database environment is PostgreSQL and the interface is a website.
The source code can be downloaded from SIPSwitch's page on Codeplex.
- SIP account creation
- Setting up a customised dial plan
- Setting up 3rd party SIP Registrations
- SIP traffic forwarding
- SIP Accounts activity monitoring via the website
- SIP traffic monitoring via telnet
- Online switchboard: call hold/resume, call transfer/forward, call hangup
- Usual security features
- Click to Call (Beta)
- Possibility to run it on a local computer
- Multiple call forwarding
- RUBY Dial plans
- ENUM Lookup
- November 2006 : Created by Aaron Clauson from Blueface
- January 2007 : Improvements thanks to user's feedback
- April 2007 : New features: call management functions, new dial plan interface
- July 2007 : Creation of a dedicated forum
- August 2007 : Bugs corrections and 3rd party registrations improvements
- October 2007 : New layout (it now looks much better)
- October 2007 : new feature: possibility to use the dial plan for incoming calls
- February 2008 : new features : click to call and local version
- March 2008 : Ruby (programming language) Dial plan
- February 2009 : New tool to automatically generate Ruby Dial Plans. more info
- June 2009 : New accounts are no longer being accepted. The mysipswitch.com site recommends that users use their new service sipsorcery.com