Traffic Shaping on ISPs

Thu Sep 10 09:49:04 UTC 2009

> While I cannot confirm officially, there is a lot of rumors, that several
> larger UK ISP's are throttling traffic at that time period.
> I am not sure who to contact, but the individual ISP's to solve this, from
> your point, maybe another NANOG'er knows.

Hi Lasse, 

Thanks for the reply. We wrote an app to reveal troubles.

Just to satisfy any curiosity and get some facts out, I will provide a real world example (1 of many) from a direct test of one of our BT sourced customers (this is from a 08-29 test at ~22:04 hours GMT):

Date			IP			RTT	Port	ActualRecv	NicSent	NicRecv
090829 22:04:24	86.128.0.0/10 	103.5	80	199	13	214
090829 22:04:24	86.128.0.0/10		103.5	80	199	13	214
090829 22:04:24	86.128.0.0/10		103.5	443	200	12	215
090829 22:04:24	86.128.0.0/10		103.5	443	199	12	214
090829 22:04:24	86.128.0.0/10		103.5	7255	2	2	5
090829 22:04:24	86.128.0.0/10		103.5	7255	3	1	4
090829 22:04:24	86.128.0.0/10		103.5	7003	3	2	5
090829 22:04:24	86.128.0.0/10		103.5	7003	4	1	5
090829 22:04:24	86.128.0.0/10		103.5	7202	27	3	32
090829 22:04:24	86.128.0.0/10		103.5	7202	24	2	29
090829 22:04:24	86.128.0.0/10		103.5	7499	27	3	32
090829 22:04:24	86.128.0.0/10		103.5	7499	25	2	31
090829 22:04:24	86.128.0.0/10		103.5	80	195	13	206
Idle NIC bandwidth  Send:     0 KB/sec   Recv:     0 KB/sec

To remove any doubt we also measured idle bandwidth utilization on the NIC when the test wasn't run to remove any other culprit such as torrent download, A/V streaming and etc in the background. In this case, 0/0 on idle use. All results are in KBytes

I withheld the actual IP address of this test and replaced it from the source prefix. We have quite a few iterations of similar results from other source addresses from this prefix alone. All appear to exhibit the same issue. 

I've already written British Telecom and they never replied.