Applications of UDP

Remote Procedure Call
• Client process calls the client stub
• Marshalling-packing the parameters
• Kernel receives from client stub and sends to server machine
• Kernel on server OS passes the message to server stub
• The server stub processes it and the reply follows the same path in the other
Problems may occur in RPC
• Passing pointer parameters from client place to server space
• weakly typed language- C may not be suitable
• Type conversion
• Use of global variables –since two different space involved
Still UDP is commonly used in RPC
Another application of UDP a protocol uses UDP
(a) The position of RTP in the protocol stack.
(b) Packet nesting.
RTP Real time transport protocol
• UDP is used with real time multimedia applications
• the applications are: internet radio, internet telephony, music on demand, video
on demand, video conferencing
• RTP is used for different formats like GSM, MP3 for sound and MPEG and
H.263 for video
• The basic function of RTP is to multiplex several real time data stream onto
single stream of UDP packets. The UDP stream can be sent to single destination
(unicast) and multiple destination (multicast)
RTP Header details
• P padded bit
• X extension header present or not
• CC contributing sources
• M marker bit
• Version field
• Payload type
• Seq no
• Time stamp
• Synchronization and contributing source identifier
RTP Header