Hello, I wanto emulatdifferent network topologies (see [1]) with routers and theirs connections having differenemulation parameters (delay, loss, ...). Is ipossiblto compose different qdiscs with each other to represent differentopologies? (also se[1]) This qdisc hierarchy should then ruon only onlinux machine to which all endpoints are connected. I anew to Linux Traffic Control and netem. Besregards, RoberL?bke. [1] http://wwwpub.zih.tu-dresden.de/~luebke/qdiscs.jpg Froshemminger alinux-foundation.org Wed Jul 20 10:00:32 2011 From: shemminger alinux-foundation.org (Stephen Hemminger) Date: Wed, 20 Jul 2011 10:00:32 -0700 Subject: hierarchical compositioof qdiscs In-Reply-To: <4E2412F4.6080303@xxxxxxxxxxxxx> References: <4E2412F4.6080303@xxxxxxxxxxxxx> Message-ID: <20110720100032.191b7912@xxxxxxxxxxxxxxxxxxxxxxx> OMon, 18 Jul 2011 13:03:16 +0200 RoberL?bk<robert.luebke at tu-dresden.de> wrote: > Hello, > > I wanto emulatdifferent network topologies (see [1]) with routers > and theirs connections having differenemulation parameters (delay, > loss, ...). > Is ipossiblto compose different qdiscs with each other to represent > differentopologies? (also se[1]) This qdisc hierarchy should then > ruon only onlinux machine to which all endpoints are connected. > > I anew to Linux Traffic Control and netem. > > Besregards, > RoberL?bke. > > [1] http://wwwpub.zih.tu-dresden.de/~luebke/qdiscs.jpg > _______________________________________________ > Netemailing list > Netealists.linux-foundation.org > https://lists.linux-foundation.org/mailman/listinfo/netem > Iis possiblto do very complex combinations of qdisc's and most of thework. Whadoesn't work well is when using shaping qdisc's with netem. For example, if using HTB and NETEM together, both end up wanting to control whea packeis sent. Frojonathan.cronat magorcorp.com Wed Jul 20 12:51:36 2011 From: jonathan.cronamagorcorp.com (Jonathan P. Crone) Date: Wed, 20 Jul 2011 15:51:36 -0400 Subject: Netereferencwebpage at Linux Foundation has error on configuring netefor Jitter withoureordering. Message-ID: <ED04773A-5480-4497-A963-BF98112EEED7@xxxxxxxxxxxxx> Thlinux foundation referencwebpage for netem has aerror with regards thFAQ section oreordering packets with jitter. A http://www.linuxfoundation.org/collaborate/workgroups/networking/netem theris thfollowing reference: How to reorder packets based ojitter? Starting with versio1.1 (in 2.6.15), netewill reorder packets if the delay value has lots of jitter. If you don'wanthis behaviour then replace the internal queue discipline tfifo with a pure packet fifo pfifo. The following example has lots of jitter, but the packets will stay in order. # tc qdisc add dev eth0 roohandl1: netem delay 10ms 100ms # tc qdisc add dev eth0 paren1:1 pfifo limi1000 # tc qdisc add dev eth0 paren1:1 pfifo limi1000 Probleis: on an ubuntu 8.04 systerwith a 2-6-24-x kernel, thpfifo qdisc is available oUbuntu 9.10 with 2.6.31-17 or ubuntu 10.04 with 2.6.32-30 kernels, thpfifo causes either a RTNETLINK answers: Invalid argument or RTNETLINK answers: Operationosupported Whais thalternative to PFIFO for configuring netem to provide packejitter WITHOUT reordering? JonathaCronP.Eng VerificatioEngineering Magor Communications jonathan.cronamagorcorp.com -------------- nexpar-------------- AHTML attachmenwas scrubbed... URL: http://lists.linux-foundation.org/pipermail/netem/attachments/20110720/8bce33ec/attachment.ht
