12:45 PM, Thursday, February 3, 2000
Room 104, Gates Computer Science Building

Application Performance Pitfalls and TCP's Nagle algorithm

Greg Minshall
Siara Systems

About the talk:

Performance improvements to networked applications can have unintended consequences. In a study of the performance of the Network News Transport Protocol (NNTP), the initial results suggested it would be useful to disable TCP's Nagle algorithm for this application. Doing so significantly improved latencies. However, closer observation revealed that with the Nagle algorithm disabled, the application was transmitting an order of magnitude more packets. We found that proper application buffer management significantly improves performance, but that the Nagle algorithm still slightly increases mean latency. We suggest that modifying the Nagle algorithm would eliminate this cost.

About the speaker:

Greg Minshall is on the technical staff of Siara Systems, a networking startup located in Silicon Valley. Previously, he was at Ipsilon Networks, Novell, Kinetics, and the University of California, Berkeley. He has been involved in the design and implementation of internet protocols, at the routing and transport layers, since the early 1980s. At one time in his life, he worked as a hardware technician/engineer on the Illiac IV SIMD computer.