SESSION INITIATION PROTOCAL

"SIP (Session Initiation Protocol) is an application-layer control protocol for creating, modifying and terminating session with one or more participants. These seSSlOns include internet multimedia distribution." SIP supports user mobility by proxying and redirecting requests to the user's current location. In this SIP the basic language used is 12ME Wireless toolkit. 12ME supports layered software for the development of applications, targeted to run on small devices such as mobile phones, pagers etc. SIP describes how the message is transfer between client and client. Both contains SIP- INVITER and SIP- RECEIVER in that one client acts as SIP- INVITER and the other is used as SIP_RECEIVER. From the first client we are sending messages & images to the other client. It requires less API classes. It is easy to implement. Up to now we have described one to one message sending and receiving. If we want to initiate more than one client for sending messages and images it requires more API classes. For initiating more than one client we require the address of those clients and send requests to the server. The server receives those requests and searches for the appropriate client. This process is carried out by different servers like Proxy server, Location server, Registrar server, Redirect server, etc.School of Computingg, Communications and Electronic