What is the purpose of "Response Codes" in SIP?

The purpose of "Response Codes" in the Session Initiation Protocol (SIP) is to convey feedback regarding the success or failure of SIP requests. When a SIP request (such as INVITE, ACK, BYE, etc.) is sent, the responding entity sends back a response code that indicates the result of that request. These response codes are essential for managing and controlling sessions in real-time communication, as they provide important information about the status of communications, whether they were successful or if there were errors encountered.

For instance, a 200 OK response indicates that the request was successfully processed, while a 404 Not Found response means that the requested resource could not be located. By utilizing these codes, systems can efficiently handle call establishment, modification, and termination processes, ensuring that all parties are aware of the state of their communication attempts.

The other options refer to functionalities that are not the primary purpose of response codes. While determining device functionality is part of network management, it doesn’t specifically relate to SIP response codes. Response codes do not initiate connections; instead, they respond to requests for establishing sessions. Furthermore, encryption of communication sessions is handled by protocols like SRTP or TLS, not by SIP response codes. Thus, the correct focus is