X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=tc-pbfifo.8;fp=tc-pbfifo.8;h=8dda4bbacc2533e2cefc1750e170db178db22e19;hb=41e3140e053cf3e92add38e167e16f4972879d16;hp=0000000000000000000000000000000000000000;hpb=cb820e861caa85bb3942ab0c673e04b9408be0ad;p=iproute2.git diff --git a/tc-pbfifo.8 b/tc-pbfifo.8 new file mode 100644 index 0000000..8dda4bb --- /dev/null +++ b/tc-pbfifo.8 @@ -0,0 +1,72 @@ +.TH PBFIFO 8 "10 January 2002" "iproute2" "Linux" +.SH NAME +pfifo \- Packet limited First In, First Out queue +.P +bfifo \- Byte limited First In, First Out queue + +.SH SYNOPSIS +.B tc qdisc ... add pfifo +.B [ limit +packets +.B ] +.P +.B tc qdisc ... add bfifo +.B [ limit +bytes +.B ] + +.SH DESCRIPTION +The pfifo and bfifo qdiscs are unadorned First In, First Out queues. They are the +simplest queues possible and therefore have no overhead. +.B pfifo +constrains the queue size as measured in packets. +.B bfifo +does so as measured in bytes. + +Like all non-default qdiscs, they maintain statistics. This might be a reason to prefer +pfifo or bfifo over the default. + +.SH ALGORITHM +A list of packets is maintained, when a packet is enqueued it gets inserted at the tail of +a list. When a packet needs to be sent out to the network, it is taken from the head of the list. + +If the list is too long, no further packets are allowed on. This is called 'tail drop'. + +.SH PARAMETERS +.TP +limit +Maximum queue size. Specified in bytes for bfifo, in packets for pfifo. For pfifo, defaults +to the interface txqueuelen, as specified with +.BR ifconfig (8) +or +.BR ip (8). + +For bfifo, it defaults to the txqueuelen multiplied by the interface MTU. + +.SH OUTPUT +The output of +.B tc -s qdisc ls +contains the limit, either in packets or in bytes, and the number of bytes +and packets actually sent. An unsent and dropped packet only appears between braces +and is not counted as 'Sent'. + +In this example, the queue length is 100 packets, 45894 bytes were sent over 681 packets. +No packets were dropped, and as the pfifo queue does not slow down packets, there were also no +overlimits: +.P +.nf +# tc -s qdisc ls dev eth0 +qdisc pfifo 8001: dev eth0 limit 100p + Sent 45894 bytes 681 pkts (dropped 0, overlimits 0) +.fi + +If a backlog occurs, this is displayed as well. +.SH SEE ALSO +.BR tc (8) + +.SH AUTHORS +Alexey N. Kuznetsov, + +This manpage maintained by bert hubert + +