diff options
| author | dillon <dillon@FreeBSD.org> | 2002-07-17 23:32:03 +0000 |
|---|---|---|
| committer | dillon <dillon@FreeBSD.org> | 2002-07-17 23:32:03 +0000 |
| commit | f7ed3f73322c863f0f06500aab654100411cb9f7 (patch) | |
| tree | 0c76fc8bf55fc9eadf73e300e965a4172f827b96 /sys/netinet/tcp_timer.h | |
| parent | 0bbdc51f985c3eb03c8db23a83aa4a263e43f3ad (diff) | |
| download | FreeBSD-src-f7ed3f73322c863f0f06500aab654100411cb9f7.zip FreeBSD-src-f7ed3f73322c863f0f06500aab654100411cb9f7.tar.gz | |
I don't know how the minimum retransmit timeout managed to get set to
one second but it badly breaks throughput on networks with minor packet
loss.
Complaints by: at least two people tracked down to this.
MFC after: 3 days
Diffstat (limited to 'sys/netinet/tcp_timer.h')
| -rw-r--r-- | sys/netinet/tcp_timer.h | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/sys/netinet/tcp_timer.h b/sys/netinet/tcp_timer.h index ff86d2a..94c8a5e 100644 --- a/sys/netinet/tcp_timer.h +++ b/sys/netinet/tcp_timer.h @@ -90,7 +90,13 @@ #define TCPTV_KEEPINTVL ( 75*hz) /* default probe interval */ #define TCPTV_KEEPCNT 8 /* max probes before drop */ -#define TCPTV_MIN ( 1*hz) /* minimum allowable value */ +/* + * Minimum retransmit timer is 3 ticks, for algorithmic stability. + * The maximum is 64 seconds. The prior minimum of 1*hz (1 second) badly + * breaks throughput on any networks faster then a modem that has minor + * (e.g. 1%) packet loss. + */ +#define TCPTV_MIN ( 3 ) /* minimum allowable value */ #define TCPTV_REXMTMAX ( 64*hz) /* max allowable REXMT value */ #define TCPTV_TWTRUNC 8 /* RTO factor to truncate TW */ |
