Do you have a graph via SNMP of the actual SM traffic? See if the AP is only scheduling the configured amount of traffic to the customer, and throwing away the rest. If yes, the Procera probably gives you the tools to limit this traffic to X% of the customer’s subscribed rate, although it will still consume your upstream bandwidth. If not, then your suspicion of Cambium sustained rate limit not working might be true. We don’t rely on that feature as a primary means of rate limiting customers, so I wouldn’t necessarily know if it is broken. If it is broken, I’m wasting a lot of money buying SM20’s.
From: Kurt Fankhauser Sent: Sunday, April 26, 2015 11:16 AM To: [email protected] Subject: Re: [AFMUG] 450SM sustain bucket throttle not working.. I'm measuring at the upstream router which is actually a Procera Box. (not actually a rotuer) Customer called last night complaining speeds were horrible.... Kurt Fankhauser Wavelinc Communications P.O. Box 126 Bucyrus, OH 44820 http://www.wavelinc.com tel. 419-562-6405 fax. 419-617-0110 On Sun, Apr 26, 2015 at 12:01 PM, Ken Hohhof <[email protected]> wrote: 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: [email protected] 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
