Internetworking circuit and connectionless networks

A new type of gateway, called a ConnectionLess Circuit (CLC) gateway is proposed to internetwork connectionless (CL) networks with dynamically shared circuit/virtual networks. In contrast with IP routers, CLC gateways implement (a) a signaling function to receive circuit setup/release requests triggered by end hosts and initiate dynamic circuit setup/release through their attached circuit subnetworks, (b) transport-layer functionality to terminate TCP connections across CL subnetworks and Circuit-TCP (CTCP) connections across circuits, and (c) disk buffering to decouple transfers across CL subnetworks from transfers across high-speed circuit subnetworks. Specifically, this internetworking architecture is proposed for large files transfers with a goal of increasing end-to-end transfer rates. A path for introducing this architecture and services into the current Internet, involving programmable patch panels in addition to CLC gateways and circuit subnetworks, is presented. A CLC gateway using web proxy Squid software is implemented. Experiments with this gateway demonstrate the need for decoupling through disk buffering and TCP/CTCP terminations. Measurements on a rate-mismatched path, with a 155 Mbps circuit between CLC gateways, and a 1 Mbps bottleneck link rate on a CL subnetwork, show that a 100 MB file transfer without disk buffering resulted in a 0.6% circuit utilization, tying up the circuit for 843.8 sec, while with disk buffering, utilization improves to 90.8% while holding the circuit for only 5.96 sec.