Do 100rel when incoming request is 100rel supported and UA is configured as rel100 required
Do 100rel when incoming request is 100rel supported and UA is configured as rel100 required

Voiceworks/SIP.js,markandrus/SIP.js,onsip/SIP.js,ronlobo/SIP.js,joseph-onsip/SIP.js,josephfrazier/SIP.js,Escaux/SIP.js,onsip/SIP.js