Add Yeti-Switch project (#2470)

README.md

@@ -415,6 +415,7 @@ _[SIP](https://en.wikipedia.org/wiki/Session_Initiation_Protocol)/[IPBX](https:/
 - [SipXcom](http://sipxcom.org/) - Open source unified communications system. ([Source Code](https://github.com/sipXcom/sipxecs)) `AGPL-3.0` `Java`
 - [SIP3](https://sip3.io/) - VoIP troubleshooting and monitoring platform. ([Demo](https://demo.sip3.io), [Source Code](https://github.com/sip3io/)) `Apache-2.0` `Kotlin`
 - [Wazo](http://wazo-platform.org/) - Full-featured IPBX solution built atop Asterisk with integrated Web administration interface and REST-ful API. ([Source Code](https://github.com/wazo-platform)) `GPL-3.0` `Python`
+- [Yeti-Switch](https://yeti-switch.org/) - Transit class4 softswitch(SBC) with integrated billing and routing engine and REST API. ([Demo](https://yeti-switch.org/demo.html), [Source Code](https://github.com/yeti-switch)) `GPL-2.0` `C++/Ruby`
 
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