What is my SIP URI?
Think of a SIP URI like an email address, but for voice calls. Your SIP URI is unique and is used by your phone system to route calls to the iCallerID servers.
Your SIP URI will look like sip:1@iCallerID.ringfree.com. You can find your SIP URI by starting the iCallerID app on your iPhone or iPod touch and touching the Settings tab.