> Fra: Pete Heist <[email protected]> > - As for low bandwidth, in my experience AQM works great on low bandwidth > ADSL. A few years ago I > used fq_codel at a campground to shape a 0.5 / 5 Mbps ADSL connection. With > up to 130 people in the > camp, it was a disaster before fq_codel, where one person saturating either > the up or downstream > could easily cause 600+ ms of induced latency. fq_codel could keep that to > 40-50 ms under load, >enough to make it usable for web browsing, at least, and Cake does better.
Thats encouraging! > It’s an interesting question: what can be done as an ISP? Essentially it > boils down to the fundamentals > of deploying AQM- finding where the queues are forming and placing fq_codel > or Cake at the > bottleneck links, preferring “hardware” queue management like BQL or in the > case of WiFi the ath9k’s > driver in LEDE, over soft rate limiting, where possible. When soft rate > limiting, the rate limiting strategy > and chosen rate are the most CPU intensive and finicky parts of deploying AQM. What I see as short term posibiliteis for us as ISP's is to push our vendors to include this as a part of the feature set. We also could do better with the maketing. Lets steal an idea from the Video area. HD is often written as 1080P@60. Why not do the same for internet speed? 60M@80ms. Where the @80ms would be the larges latency in either direction that queue management would introduce? (This of cource introduces the risk of artificialy tuning the @xxms to low and ending up with strict policing) > - I don't understand why ADSL modem vendors don’t just bake BQL-like > functionality right into their > devices so they can ship AQM without the need for soft rate limiting. AQM is > so effective on ADSL's > upstream that it seems it would just make a lot of sense. For that matter, > why not on the DSLAM as well > to shape the customer’s downstream, if that’s also a bottleneck? I think most ISP's handle shaping on the BRAS level rather than on the DSLAM, as DSLAM's in general have very limited shaping/qos capabilites. Regarding CPEs, to be fair, up coming devices from Intel (Lantiq) will more or less do away with HW accellerators and do everything in software. Then the vendors are a lot more free to implement better shapeing strategies. The trade shows and all sales pitches focuses mostly on next gen stuff. There are comparatively very little recources dedicated to ADSL, where the best schedulers is most needed. -Erik _______________________________________________ Cake mailing list [email protected] https://lists.bufferbloat.net/listinfo/cake
