Performance analysis of the TCP/IP protocol under UNIX operating systems for high performance computing and communications

Among many protocols, the TCP/IP protocol suite is the most widely used form of networking computers. With the advent of high-speed communication paradigms such as asynchronous transfer mode (ATM) and the advances of transmission media technologies such as optical fibers, the physical transmission medium is no longer the performance bottleneck in communication systems. Thus, transport layers are currently receiving much attention, since they don't seem to convey the large bandwidths of the lower layers to the application users properly. Many other transport protocols have been proposed and implemented, which might perform better than TCP/IP. However, due to the popularity of TCP/IP, no other protocols seem to ready to take its place in the near future. Thus, emerging bandwidth-hungry applications steadily require higher and higher TCP/IP performance. In this paper, we analyze the performance of TCP/IP under the UNIX operating system in exchanging data once a connection is established. By measuring accurate data for the various aspects of the protocol implementation, we clearly illustrate the major bottlenecks and determine the upper bounds on performance. We also measure memory bandwidth requirements in processing high-speed TCP/IP. Empirical results show that the TCP/IP protocol itself can handle up to 85 Mbps to process data under the UNIX operating system when a proper data link layer interface is provided, requiring a memory bandwidth of 172 MByte/s.