Nagle's algorithm: Difference between revisions

Revision as of 15:45, 6 January 2016

Revision as of 07:31, 11 January 2016

Line 1:

{{ref improve|date=June 2014}}

'''Nagle's algorithm''', named after John Nagle, is a means of improving the efficiency of [[TCP/IP]] networks by reducing the number of packets that need to be sent over the network. It was defined by John Nagle while working for Ford Aerospace and Communications Corporation.

Nagle's document, ''Congestion Control in IP/TCP Internetworks'' (RFC 896) describes what he called the "small packet problem", where an application repeatedly emits data in small chunks, frequently only 1 [[byte]] in size. Since [[Transmission Control Protocol|TCP]] packets have a 40 byte header (20 bytes for TCP, 20 bytes for [[IPv4]]), this results in a 41 byte packet for 1 byte of useful information, a huge overhead. This situation often occurs in [[Telnet]] sessions, where most keypresses generate a single byte of data that is transmitted immediately. Worse, over slow links, many such packets can be in transit at the same time, potentially leading to [[congestion collapse]].