similar to: Delay packets by 50ms

I want to build a "network simulator", to create scenarios such as delayed packets, lost packets, low bandwidth, or combinations of such. This document has been helpful for everything except the bandwidth: http://linux-net.osdl.org/index.php/Netem There is some documentation here regarding bandwidth: http://luxik.cdi.cz/~devik/qos/htb/ What''s the best documentation to read

Hello, I'd like to change some network variables (bandwidth, delay, packet loss) to measure how speex behaves in certain conditions. Do you recommend any tools you may use in speex development? It seems NIST Net isn't maintained anymore. I've found dummynet, looks interesting, but any hints you guys may have would be most welcome... Thanks, -- Adriano

I''m trying to simulate a satellite link to a Linux server to test application performance. I haven''t used any of the tc stuff before, but I blandly assured people it would be "easy" to set up a simulated long thin pipe on a spare network interface. However, now that I''m exploring, it''s proving quite difficult. Let me start with the general question

This patch updates the network emulation packet scheduler. * name changed from delay to netem since it does more than just delay * Catalin''s merged code to do packet reordering * uses a socket queue''s directly rather than layering on qdisc(fifo) because this is used in performance tests. * adds placeholder in API for future enhancements (rate and duplicate).

I''m trying to build a wan latency test environment, where packets from different "remote" locations get delayed by different amounts of time, depending on which remote location we''re pretending they are from. Currently, I''m doing this using the ''prio'' qdisc to obtain multiple bands, and hanging a different netem qdisc off each of the branches

Hi! We want to run TCP streams to several port numbers through one interface, each with a different delay set by Netem. E.g. TCP streams to port 80 could have 50ms delay, while TCP streams to port 81 could have 100 ms delay and so on. We have tried to solve this by using a combination of tc filter and netem rules, but we can''t get it quite right. We are considering one class per port,

There is an design problem with the qdisc interface that causes qlen related bugs in netem, tbf, and other qdisc''s that peek at the top of the queue. The problem is that requeue needs to be called from the dequeue function but requeue can fail. If requeue fails, then the calling qdisc can not properly handle the error. If it returns NULL, then the parent''s expectation about qlen

Well. I want to test subnet propagation, alternate paths, etc... Do this, I would use Imunes because im very familiar with it.. I want to build small test network around 10 nodes with different connectivity between them and then lay-out tinc network on it. Then I can just set BER=1 to kill links and see how things happen etc.. Nice spot about ng_eiface indeed. I'll check it out.. As for

Hi folks, I am building a new box. Want it to look pretty much like an older Asterisk 1.2, Debian box that is in production. The new box will used as a test box before we implement changes to the production box. New box: ================================================ # cat /etc/issue; uname -a Debian GNU/Linux 4.0 \n \l Linux ServerName 2.6.18-6-686 #1 SMP Mon Oct 13 16:13:09 UTC 2008

Hello, I was attempting to throttle egress traffic to a specific rate using a tbf. As a starting point I used an example from the LARTC howto, which goes: tc qdisc add dev eth1 root tbf rate 220kbit latency 50ms burst 1540 I then attempt a large fetch from another machine via wget (~40 megs) and the rate was clamped down to about 12Kbytes/s. As this seemed too much, I gradually increased

In ocfs2-1.2, when we mount a device, a debugfs dir will be created using its uuid. When 2 devices have the same uuid, after the 1st device is mounted, the 2nd one can't be mounted. This is OK. But the problem is that the dentry's reference is added. So when the 1st volume is umounted, none of these 2 volumes can be mounted then. So this fix solves this problem by dputting the

Hi everyone, I''m doing some networking experiments over high BDP topologies. Right now the configuration is quite simple -- two Xen boxes connected via a dummynet router. The dummynet router is set to limit bandwidth to 500Mbps and simulate an RTT of 80ms. I''m using the following sysctl values: net.ipv4.tcp_rmem = 4096 87380 4194304 net.ipv4.tcp_wmem = 4096

I have setup some qdiscs and filters more or less straight from the howto. they work pretty good. however, when i delete one filter or all of them, they all appear to be deleted (as shown by "tc filter show dev ppp0"). the real problem is, that as soon as i recreate a single filter, all the deleted filters reappear along with the new one. thus i have an ever increasing set of filters.

Hi, I am using netem to add loss and then adding another qdisc within netem according to the wiki. Then i want to change the netem drop probability without having to delete the qdisc and recreate it. I try it but I get invalid argument: thorium-ini hedpe # tc qdisc add dev ath0 root handle 1:0 netem drop 1% thorium-ini hedpe # tc qdisc add dev ath0 parent 1:1 handle 10: xcp capacity 54Mbit

I first met this problem when our (60 students) internetgateway refused to boot its new kernel, it was a 4.7-RELEASE. Then i loaded the old kernel and went home to check if my 4.8-STABLE does likewise. And the answer was yes! Both kernels were GENERIC + these options taken from the dummynet man pages: options DUMMYNET options NMBCLUSTERS options HZ When i boot the machine

The following (occuring on debian/testing with kernel-image-2.6.8-2-386 version 2.6.8-13 and iproute version 20041019-3) confuses me: # tc qdisc add dev eth0 root handle 1: prio # tc filter add dev eth0 parent 1: proto ip pref 1 handle 1 fw classid 1:2 # tc filter ls dev eth0 filter parent 1: protocol ip pref 1 fw filter parent 1: protocol ip pref 1 fw handle 0x1 classid 1:2 # tc filter del dev

Hi, I am using iproute2 to setup fowarding, adding routes like "ip route add 192.168.1.3 via 192.168.1.2" I was wondering where in the kernel I can insert probabilistic packet loss only for forwarded packets? So that for instance I can drop 5% of all forwarded packets? I don''t need help with the actual code, just need help finding where to insert this code :) Thanks! George

I''m trying to setup a netem delay with no luck (using iproute2-2.6.8, compilation broke during arpd compile, so I use the tc binary in the tc/ subdir, there''s also a q_netem.so there). kernel is 2.6.8.1, compile with CPU cycle counter as time reference. I was using sch_delay of 2.6.7 happily with something like: tc qdisc add dev eth0 root 1: delay latency 1ms rate 35M now I use:

Greetings, Scenario: Centos box with eth1 (10.0.0.0/24) and eth0 (192.168.0.0/24) segment on eth0 has access to full bandwidth of uplink Both are on 100mbps switches Requirements: bandwith on segment on eth1 needs to be throttled to different speeds - say 32, 64, 128kbps and the such. Required for application performance testing purposes. As usual my girlfriend google is very verbose.

Interesting table Karan!, Could you please tell us how you did the benchmark? fio or iozone orsimilar? thanks Arman. On Wed, Sep 27, 2017 at 1:20 PM, Karan Sandha <ksandha at redhat.com> wrote: > Hi Collin, > > During our arbiter latency testing for completion of ops we found the > below results:- an arbiter node in another data centre and both the data > bricks in the