PERFORMANCE OF END-TO-END FLOW-CONTROL IN LAN/WAN INTERCONNECTION

This paper deals with end-to-end flow control for a multinetwork environment in which several LANs and some host computers are interconnected via private or public packet switched WANs. The multinetwork environment considered here is a typical LAN/WAN interconnection through IP routers. A private WAN usually spans a small geographic area and consists of a set of IP routers interconnected by leased communication lines. A public WAN usually covers a large area and adopts X.25 protocols. As a ne facto, TCP/IP has been implemented on nearly every LAN interconnection, especially in conjunction with Ethernet. To transport TCP/IP internet traffic to the LAN that cannot afford to be directly connected to the private WAN, one can use the public X.25 connection. In this environment there exist two flow control mechanisms, one each for the TCP and the X.25, under which the X.25 mechanism is nested into the TCP mechanism. In this paper, end-to-end flow control implies these two flow control mechanisms together. The purpose of this paper is to provide analytical methods to determine optimal or suboptimal parameters of end-to-end flow control.