| | 1 | .\" |
| | 2 | .\" $FreeBSD: /repoman/r/ncvs/src/share/man/man4/dummynet.4,v 1.4.2.12 2002/11/18 21:51:16 luigi Exp $ |
| | 3 | .\" |
| | 4 | .Dd October 28, 2002 |
| | 5 | .Dt DUMMYNET 4 |
| | 6 | .Os Darwin |
| | 7 | .Sh NAME |
| | 8 | .Nm dummynet |
| | 9 | .Nd traffic shaper, bandwidth manager and delay emulator |
| | 10 | .Sh DESCRIPTION |
| | 11 | .Em dummynet |
| | 12 | is a system facility that permits the control of traffic |
| | 13 | going through the various network interfaces, by applying bandwidth |
| | 14 | and queue size limitations, implementing different scheduling and queue |
| | 15 | management policies, and emulating delays and losses. |
| | 16 | .Pp |
| | 17 | The user interface for |
| | 18 | .Em dummynet |
| | 19 | is implemented by the |
| | 20 | .Nm ipfw |
| | 21 | program, so the reader is referred to the |
| | 22 | .Xr ipfw 8 |
| | 23 | manpage for a complete description of the capabilities of |
| | 24 | .Nm |
| | 25 | and on how to use it. |
| | 26 | .Sh KERNEL OPTIONS |
| | 27 | The following options in the kernel configuration file are related to |
| | 28 | .Nm |
| | 29 | operation: |
| | 30 | .Bd -literal |
| | 31 | IPFIREWALL - enable ipfirewall (required for dummynet). |
| | 32 | IPFIREWALL_VERBOSE - enable firewall output. |
| | 33 | IPFIREWALL_VERBOSE_LIMIT - limit firewall output. |
| | 34 | DUMMYNET - enable dummynet operation. |
| | 35 | NMBCLUSTERS - set the amount of network packet buffers |
| | 36 | HZ - sets the timer granularity |
| | 37 | .Ed |
| | 38 | .Pp |
| | 39 | Generally, the following options are required: |
| | 40 | .Bd -literal |
| | 41 | options IPFIREWALL |
| | 42 | options DUMMYNET |
| | 43 | options HZ=1000 # strongly recommended |
| | 44 | .Ed |
| | 45 | .Pp |
| | 46 | additionally, one may want to increase the number |
| | 47 | of mbuf clusters (used to store network packets) according to the |
| | 48 | sum of the bandwidth-delay products and queue sizes of all configured |
| | 49 | pipes. |
| | 50 | .Sh SEE ALSO |
| | 51 | .Xr setsockopt 2 , |
| | 52 | .Xr bridge 4 , |
| | 53 | .Xr ip 4 , |
| | 54 | .Xr ipfw 8 , |
| | 55 | .Xr sysctl 8 |
| | 56 | .Sh HISTORY |
| | 57 | .Nm |
| | 58 | was initially implemented as a testing tool for TCP congestion control |
| | 59 | by |
| | 60 | .An Luigi Rizzo Aq luigi@iet.unipi.it , |
| | 61 | as described on ACM Computer Communication Review, Jan.97 issue. |
| | 62 | Later it has been then modified to work at the ip and bridging |
| | 63 | level, integrated with the IPFW packet filter, and extended to |
| | 64 | support multiple queueing and scheduling policies. |
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