From: http://success.ringcentral.com/articles/RC_Knowledge_Article/How-to-Get-the-SIP-Configuration-needed-for-Manual-Provisioning-2013?retURL

From: http://success.ringcentral.com/articles/RC_Knowledge_Article/4543?retURL=%2Fapex%2FRCSupportPortalSearchNew%26type%3DFAQ%26id%3DkA280000000GsvoCAC%26Title%3DUpdated+SIP+Servers+for+manually+provisioned+IP+phones

SIP Domain sip.rengcentral.com:5060
Outbound Proxy: sip20.ringcentral.com:5090
New Servers
sip10.ringcentral.com or 199.255.120.176
sip20.ringcentral.com or 199.255.120.177

To configure your device to connect to the RingCentral service, you will need to program it with the following information.
The steps for programming will vary from device to device, so please check with your device's manufacturer for specific instructions.
Field			Value
SIP Domain		sip.ringcentral.com:5060
Outbound Proxy		sip10.ringcentral.com:5090
User Name		15555551212
Password		1234567
Authorization ID	1234567


Actual Device Info

	System Description:	Mediatrix 4108 v5.0.19.124 SIP MIB 1.5.3.67 Profile MX-S5001-02-E
	Firmware Version:	5.0.19.124


SIP ... Configuration

SIP Server Source:	 		Static 	 
  	Registrar Host: 		sip.ringcentral.com 	 
  	Registrar Port: 		5060 	 
  	Proxy Host: 			sip.ringcentral.com 	 
  	Proxy Port: 			5060 	 
  	Outbound Proxy Host: 		sip10.ringcentral.com 	 
  	Outbound Proxy Port: 		5090 	 
  	Presence Compositor Host: 	0.0.0.0 	 
  	Presence Compositor Port: 	0 	



SIP Server Source: 	Static
	 
  	SIP Port: 			5060 
  	SIP Domain: 			sip.ringcentral.com
  	Registrar Host: 		sip.ringcentral.com	 
  	Registrar Port: 		5060	 
  	Proxy Host: 			sip.ringcentral.com 
  	Proxy Port: 			5060 
  	Outbound Proxy Host: 		sip10.ringcentral.com	 
  	Outbound Proxy Port: 		5090	 
  	Presence Compositor Host:	0.0.0.0 		 
  	Presence Compositor Port:	0 		 
  	Unregistered Port Behavior:	Disdable Port 	 

SIP User Configuration 	 
	Port 	User Name 	Friendly Name 	Other Accepted Username 	 
  	1 	15555551212			 
  	2 				 
  	3 				 
  	4 				 
  	5 				 
  	6 				 
  	7 				 
  	8 		


SIP ... Authentication

User Agent Authentication 	 
	Port 	Index 	Validate Realm 	Realm 	Username 	Password 	 
  	1 	1 	sip.ringcentral.com	9876543		9876543	 
  	1 	2 					 
  	1 	3 					 
  	1 	4 					 
  	1 	5 					 
  	2 	1 					 
  	2 	2 					 
  	2 	3 					



TELEPHONY ... CODEC

Preferred Codec: 		 G711-PCMU

Mediatrix_UMNv3_2r24_52.zip

Mediatrix’s Unit Manager Network is a user-friendly element management system
designed to facilitate the deployment, configuration and provisioning of 
Mediatrix access devices and gateways.