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author | sheldonh <sheldonh@FreeBSD.org> | 2000-03-01 14:50:24 +0000 |
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committer | sheldonh <sheldonh@FreeBSD.org> | 2000-03-01 14:50:24 +0000 |
commit | b45b9e3cde3c8b803fc2c4fbdb784fc378ced24d (patch) | |
tree | 0b7d3487005ae5a1da0062d675a3bf21249410eb /share/man/man4/dummynet.4 | |
parent | 46cac19efdca36bb719c540488e5b984e7370eca (diff) | |
download | FreeBSD-src-b45b9e3cde3c8b803fc2c4fbdb784fc378ced24d.zip FreeBSD-src-b45b9e3cde3c8b803fc2c4fbdb784fc378ced24d.tar.gz |
Remove single-space hard sentence breaks. These degrade the quality
of the typeset output, tend to make diffs harder to read and provide
bad examples for new-comers to mdoc.
Diffstat (limited to 'share/man/man4/dummynet.4')
-rw-r--r-- | share/man/man4/dummynet.4 | 18 |
1 files changed, 12 insertions, 6 deletions
diff --git a/share/man/man4/dummynet.4 b/share/man/man4/dummynet.4 index 62b89d5..d74ca1e 100644 --- a/share/man/man4/dummynet.4 +++ b/share/man/man4/dummynet.4 @@ -30,7 +30,8 @@ A dummynet is characterized by a bandwidth, delay, queue size, and loss rate, which can be configured with the .Nm ipfw -program. Pipes are +program. +Pipes are numbered from 1 to 65534, and packets can be passed through multiple pipes depending on the ipfw configuration. .Pp @@ -85,7 +86,8 @@ the ``pipe'' describing such limitations. .Pp Selected packets are first queued in a bounded size queue, from which they are extracted at the programmed rate and passed to a second queue -where delay is simulated. At the output from the second queue packets +where delay is simulated. +At the output from the second queue packets are reinjected into the protocol stack at the same point they came from (i.e. ip_input(), ip_output(), bdg_forward() ). Depending on the setting of the sysctl variable @@ -96,7 +98,8 @@ destination, or passed again through the rules, starting from the one after the matching rule. .Pp .Nm dummynet -performs its task once per timer tick. The granularity of operation is +performs its task once per timer tick. +The granularity of operation is thus controlled by the kernel option .Bd -literal options HZ @@ -104,9 +107,11 @@ thus controlled by the kernel option whose default value (100) means a granularity of 10ms. For an accurate simulation of high data rates it might be necessary to -reduce the timer granularity to 1ms or less. Consider, however, +reduce the timer granularity to 1ms or less. +Consider, however, that some interfaces using programmed I/O may require a considerable -time to output packets. So, reducing the granularity too much might +time to output packets. +So, reducing the granularity too much might actually cause ticks to be missed thus reducing the accuracy of operation. @@ -177,6 +182,7 @@ dummynet. dummynet was initially implemented as a testing tool for TCP congestion control by Luigi Rizzo <luigi@iet.unipi.it>, as described on ACM Computer -Communication Review, Jan.97 issue. Later it has been then modified +Communication Review, Jan.97 issue. +Later it has been then modified to work at the ip and bridging level, and integrated with the IPFW packet filter. |