Connectionless vs Connection-Oriented Servers

• Programmer can choose a connection-oriented server or a connectionless server

• User Datagram Protocol (UDP)
  connectionless
  a single socket can send and receive packets from many different computers
  best effort delivery
  some packets may be lost
  some packets may arrive out of order

• Transmission Control Protocol
  connection-oriented
  a client must connect a socket to a server
  TCP socket provides bidirectional channel between client and server
  Lost data is re-transmitted
  Data is delivered in-order
  Data is delivered as a stream of bytes
  TCP uses flow control

• It is simple for a single UDP server to accept data from multiple clients and reply

• It is easier to cope with network problems using TCP