Sorry to answer a question with a question, but are you measuring at the SM, or at some upstream router?
The reason I ask, is I have seen some CDN traffic that does not seem to follow traditional TCP congestion control. It will send at twice the rate limit, causing 50% packet loss to its own traffic and everything else to that same subscriber. Evidently some TCP geniuses have decided to use latency rather than packet loss as the indicator of congestion, and that the objective is goodput not throughput. Works for last mile technologies like T1 and DSL with big buffers at the head end of the fixed speed serial connection, not so good with the type of rate limit queues we tend to use unless we can provision the queues with big buffers. Probably not your problem, but I thought I’d bring it up just in case. From: Kurt Fankhauser Sent: Sunday, April 26, 2015 10:50 AM To: af@afmug.com Subject: [AFMUG] 450SM sustain bucket throttle not working.. I have a 450 SM that is rate limited in the SM to 1500kbps download on the sustain side. I noticed last night that this customer was pulling a steady almost 3mbps download for several hours on end. How is this possible? Is there a problem with 13.2 firmware? Its a 3.65ghz SM. see attached. Kurt Fankhauser Wavelinc Communications P.O. Box 126 Bucyrus, OH 44820 http://www.wavelinc.com tel. 419-562-6405 fax. 419-617-0110
