Hello, I am attempting to use the LARTC traffic control to simulate a radio link that has variable bandwidth and availability. The basic bandwidth could be as low as 500 bits/sec but will generally be about 4000 bits/sec. If the simulated radio link is unavailable (zero bandwidth) then packets should be queued until a link is re-established. i.e. Initial bandwidth is 5000bits/sec then to 0 bits/sec and back to 5000bits/sec However, I am having several different problems Problem 1: Setting a very low bandwidth tbf - if the rate is less than my ethernet MTU size then packets appear to just get thrown away Problem 2: Preventing packets being sent instantaneously then arrive at the tbf (because sufficient tokens are available in the bucket?) I have tried to set the burst and minburst parameters but packets still appear to be transmitted too soon (e.g. a 5000bit packet should be delayed for 1 second on a 5000bit link) Problem 3: Is it possible to stop the flow of data when the simulated link is unavailable - whilst still keeping a queue of packets The tc command line I am using is tc qdisc add dev eth0 root tbf rate 5kbit burst 0.01kbit limit 50kbit peakrate 5kbit minburst 500 and to simulate a temporary link loss I use tc qdisc change dev eth0 root tbf rate 0.001kbit burst 0.01kbit limit 50kbit peakrate 5kbit minburst 500 Any help would be much appreciated. -- Nick Howden - Senior IT Analyst QinetiQ Trusted Information Management Woodward Building, Room B009 Malvern Technology Park, WR14 3PS Telephone 01684 895566, Fax 896660 The Information contained in this E-Mail and any subsequent correspondence is private and is intended solely for the intended recipient(s). For those other than the recipient any disclosure, copying, distribution, or any action taken or omitted to be taken in reliance on such information is prohibited and may be unlawful _______________________________________________ LARTC mailing list / LARTC@xxxxxxxxxxxxxxx http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://lartc.org/
