Hagen Paul Pfeifer 7bc0f28c7a netem: rate extension ... Currently netem is not in the ability to emulate channel bandwidth. Only static delay (and optional random jitter) can be configured. To emulate the channel rate the token bucket filter (sch_tbf) can be used. But TBF has some major emulation flaws. The buffer (token bucket depth/rate) cannot be 0. Also the idea behind TBF is that the credit (token in buckets) fills if no packet is transmitted. So that there is always a "positive" credit for new packets. In real life this behavior contradicts the law of nature where nothing can travel faster as speed of light. E.g.: on an emulated 1000 byte/s link a small IPv4/TCP SYN packet with ~50 byte require ~0.05 seconds - not 0 seconds. Netem is an excellent place to implement a rate limiting feature: static delay is already implemented, tfifo already has time information and the user can skip TBF configuration completely. This patch implement rate feature which can be configured via tc. e.g: tc qdisc add dev eth0 root netem rate 10kbit To emulate a link of 5000byte/s and add an additional static delay of 10ms: tc qdisc add dev eth0 root netem delay 10ms rate 5KBps Note: similar to TBF the rate extension is bounded to the kernel timing system. Depending on the architecture timer granularity, higher rates (e.g. 10mbit/s and higher) tend to transmission bursts. Also note: further queues living in network adaptors; see ethtool(8). Signed-off-by: Hagen Paul Pfeifer <hagen@jauu.net> Acked-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@drr.davemloft.net>		2011-11-30 23:18:35 -05:00
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act_api.c
act_csum.c
act_gact.c
act_ipt.c
act_mirred.c
act_nat.c
act_pedit.c
act_police.c
act_simple.c
act_skbedit.c
cls_api.c
cls_basic.c
cls_cgroup.c
cls_flow.c	cls_flow: use skb_flow_dissect()	2011-11-28 19:09:28 -05:00
cls_fw.c
cls_route.c
cls_rsvp6.c
cls_rsvp.c
cls_rsvp.h
cls_tcindex.c
cls_u32.c
em_cmp.c
em_meta.c
em_nbyte.c
em_text.c
em_u32.c
ematch.c
Kconfig
Makefile
sch_api.c
sch_atm.c
sch_blackhole.c
sch_cbq.c
sch_choke.c	sch_choke: use skb_flow_dissect()	2011-11-29 13:17:03 -05:00
sch_drr.c
sch_dsmark.c
sch_fifo.c
sch_generic.c	net: Add queue state xoff flag for stack	2011-11-29 12:46:19 -05:00
sch_gred.c
sch_hfsc.c
sch_htb.c
sch_ingress.c
sch_mq.c	net: Add export.h for EXPORT_SYMBOL/THIS_MODULE to non-modules	2011-10-31 19:30:30 -04:00
sch_mqprio.c
sch_multiq.c	net: Add queue state xoff flag for stack	2011-11-29 12:46:19 -05:00
sch_netem.c	netem: rate extension	2011-11-30 23:18:35 -05:00
sch_prio.c
sch_qfq.c
sch_red.c
sch_sfb.c	sch_sfb: use skb_flow_dissect()	2011-11-28 19:09:28 -05:00
sch_sfq.c	sch_sfq: use skb_flow_dissect()	2011-11-29 13:17:03 -05:00
sch_tbf.c
sch_teql.c	net: Add queue state xoff flag for stack	2011-11-29 12:46:19 -05:00