go-sip
https://github.com/jart/gosip (which honestly looks magnitudes better than mine) or something instead
This library is unmaintained, I highly recommend you against using this as I wrote this as a very quick hacky high school project. UseA Go (golang) library to interface with SIP (Session Initiation Protocol) as defined in RFC 3261. This library is a work in progress, and strives to follow Go standards. This library may or may not ever be finished.
License
go-sip is licensed under the MIT License which can be found here.