About tcp_fastimo() and tcp_slowtimo()
kwl02r at ecs.soton.ac.uk
Wed May 19 02:01:47 PDT 2004
I just follow the book "TCP/IP illustrate vol 2" to understand more
about TCP timer. In the book, tcp_fastimo() is invoked each 200 ms to do
delay ack job and tcp_slowtimo() is invoked each 500 ms to do the rest
of other tcp times. But at the last version of FreeBSD source code, I
couldn't find tcp_fastimo() anymore and tcp_slowtimo() is quite
different compared with source code present at book. My questions are:
At the new FreeBSD:
1. Did delay ack time still be detected each 200ms? Which function do
this job? If not, can anybody help to describe some detail things about
delay ack time at freebsd source code.
2. The new tcp_slowtimo() following is invoked each 500ms, but seems
only detects tcp_keepintvl timer, how about other timers (eg. SYN,
s = splnet();
tcp_maxidle = tcp_keepcnt * tcp_keepintvl;
3. Did TCP timer (detect 200 or 500 ms each time) doing the same job
under the LINUX kernel?
4. Any web or book can find detail describe at source code about TCP
timer under both FreeBSD and Linux kernel?
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