Below will offer you insight into the basics of SIP signaling.
SIP is establishing sessions between two or more telecommunications devices over the Internet.
- INVITE :Invites a user to a call
- ACK : Acknowledgement is used to facilitate reliable message exchange for INVITEs.
- BYE :Terminates a connection between users
- CANCEL :Terminates a request, or search, for a user. It is used if a client sends an INVITE and then changes its decision to call the recipient.
- OPTIONS :Solicits information about a server's capabilities.
- REGISTER :Registers a user's current location
- INFO :Used for mid-session signaling
- 1xx: Provisional -- request received, continuing to process the request;
- 2xx: Success -- the action was successfully received, understood, and accepted;
- 3xx: Redirection -- further action needs to be taken in order to complete the request;
- 4xx: Client Error -- the request contains bad syntax or cannot be fulfilled at this server;
- 5xx: Server Error -- the server failed to fulfill an apparently valid request;
- 6xx: Global Failure -- the request cannot be fulfilled at any server.