Chapter 19

p. 265

RFC 2581 says that acknowledgements MUST NOT be delayed for more than 500ms. Apparently, Linux systems turn off delayed ACKs during the sender's ``slow start'' process (as guessed). It also appears (May 2002) that midge does not delay the first ACK for data (as opposed to the SYN) on any connection. This is a recommendation in RFC 2757.

p. 267

Not only do tinygrams consume bandwidth, they also consume CPU time in routers. Since today's high-performance routers consume CPU time largely independently of the size of the packet, this may be more serious.

A distressing tendency has been observed of both browsers and web servers to turn off Nagle: this has been observed to cause extra packet sends without improving performance.