This document explains "How to Add/Modify the User-Agent SIP header in the SIP Profiles ?" . Sometimes SIP header Modification is required in a Service provider network where the Device rejects an unknown header and expects optional header value or parameter.
When we register the Cisco Router as SIP Gateway, the Provider will see the Router's Registered name as "User-Agent: Cisco-SIPGateway/IOS-12.x" in the SIP header. Is it possible to Rename the SIP User-Agent Name ?
Sample SIP INVITE message with the User-Agent name ( field is highlighted in bold):