To avoid this, the Snoop protocol has been proposed. A talks to a base-station B over a single wireless hop. Normally A and C communicate with the TCP protocol, and TCP provides a reliable byte-stream where the end hosts request retransmission if a packet is lost. Snoop proposes that B will cache TCP packets sent from C to A so that if the packets are lost between B and A, B can reply them directly rather than requiring A to ask C for them to be retransmitted. Consider a program running on a network of workstations connected by Ethernet.
Workers have calendars saying what their schedule is.
This information can be stored on their PDAs and a central server computer. Suppose we're designing this system according to Clark and Svoboda's goals of autonomy. Suppose other person want to view a co-worker's calendar. Suppose we want the server computer to schedule a meeting for several people, some of whom are out of the office. Suppose they return to the office and we to change the time of a meeting with several people.