Re: [Bloat] PhD thesis with results related to buffering needs on variable-capacity links
Through my work in Domos I have at least some insight into this. My impression is that it starts with business decisions, where the focus has been on maximum throughput numbers because that's what consumers think they want. It also takes effort, focus, and (most importantly) money to remove bufferbloat, so unless there is sufficient incentives from the commercial side of things it doesn't happen. I do think there is increasing awareness of latency (under load) as an important factor for user experience. We certainly see that from some of the (dare I say thought-leading) ISPs we're working with. I think there's hope we will see more good low-latency solutions deployed in the near future. I’m hoping that you get good traction and market visibility on the latency with your ISP work. Perhaps that will inspire the management in some other ISP’s in you region… -Erik ___ Bloat mailing list Bloat@lists.bufferbloat.net https://lists.bufferbloat.net/listinfo/bloat
Re: [Bloat] PhD thesis with results related to buffering needs on variable-capacity links
Bjørn Ivar Teigen via Bloat writes: > Hi everyone, > > I defended my PhD in December. I hope some of the results are interesting > to the bufferbloat community. > > The title is "Opportunities and Limitations in Network Quality > Optimization: Quality Attenuation Models of WiFi Network Variability" > Full text here: https://www.duo.uio.no/handle/10852/98385 Congratulations! Looks interesting, I look forward to looking at it in more detail :) -Toke ___ Bloat mailing list Bloat@lists.bufferbloat.net https://lists.bufferbloat.net/listinfo/bloat
Re: [Bloat] PhD thesis with results related to buffering needs on variable-capacity links
Hi Michael, On Tue, 3 Jan 2023 at 16:08, Michael Richardson wrote: > > Thank you for sharing your thesis! > > Bjørn Ivar Teigen via Bloat wrote: > > The thesis begins by investigating which performance issues are most > > prevalent in today's WiFi networks. We show that both queuing latency > > and the WiFi protocol specification itself are significant > > contributors. By building a model of the WiFi protocol behavior we > > quantify the performance of the protocol in terms of quality > > attenuation. We find that significant performance variability is an > > inherent consequence of the protocol design. > > I guess that your thesis is mostly technical. > (I haven't clicked on the link yet) > You are right. It is focused on analyzing models of the WiFi MAC layer to calculate how good (or bad!) latency and packet loss gets in various scenarios, and how that latency and packet loss in turn affects congestion control algorithms. > > I wonder if there is work that might occur from the business department end > of things. Why do we have 15 years of WiFi optimization, which seem to be > taking us further away from low latency. Are the new protocols actually > improving the situation for the end consumer? My impression is no. > Nobody notices because the quality is so unpredictable. > Through my work in Domos I have at least some insight into this. My impression is that it starts with business decisions, where the focus has been on maximum throughput numbers because that's what consumers think they want. It also takes effort, focus, and (most importantly) money to remove bufferbloat, so unless there is sufficient incentives from the commercial side of things it doesn't happen. I do think there is increasing awareness of latency (under load) as an important factor for user experience. We certainly see that from some of the (dare I say thought-leading) ISPs we're working with. I think there's hope we will see more good low-latency solutions deployed in the near future. Cheers, -- Bjørn Ivar Teigen Head of Research +47 47335952 | bj...@domos.no | www.domos.no ___ Bloat mailing list Bloat@lists.bufferbloat.net https://lists.bufferbloat.net/listinfo/bloat
Re: [Bloat] PhD thesis with results related to buffering needs on variable-capacity links
Thank you for sharing your thesis! Bjørn Ivar Teigen via Bloat wrote: > The thesis begins by investigating which performance issues are most > prevalent in today's WiFi networks. We show that both queuing latency > and the WiFi protocol specification itself are significant > contributors. By building a model of the WiFi protocol behavior we > quantify the performance of the protocol in terms of quality > attenuation. We find that significant performance variability is an > inherent consequence of the protocol design. I guess that your thesis is mostly technical. (I haven't clicked on the link yet) I wonder if there is work that might occur from the business department end of things. Why do we have 15 years of WiFi optimization, which seem to be taking us further away from low latency. Are the new protocols actually improving the situation for the end consumer? My impression is no. Nobody notices because the quality is so unpredictable. signature.asc Description: PGP signature ___ Bloat mailing list Bloat@lists.bufferbloat.net https://lists.bufferbloat.net/listinfo/bloat
[Bloat] PhD thesis with results related to buffering needs on variable-capacity links
Hi everyone, I defended my PhD in December. I hope some of the results are interesting to the bufferbloat community. The title is "Opportunities and Limitations in Network Quality Optimization: Quality Attenuation Models of WiFi Network Variability" Full text here: https://www.duo.uio.no/handle/10852/98385 Here is the abstract: The topic of this thesis is the performance of computer networks as measured by latency and packet loss. The maximum capacity, also known as bandwidth, of computer networks has been steadily improving for decades. As more capacity becomes available, new and higher bandwidth applications emerge, further increasing demand for network resources. Performance in terms of latency and packet loss has not seen the same regular improvement. Many applications convey real-time interactions, and these depend on low latency and low packet loss for optimal performance. Optimizing network latency is a complex task. Physical transmission time, scheduling, queuing, and interactions between traffic sources can all contribute to the latency we observe. The challenge of reducing latency in the Internet has received increasing attention in recent years. This attention has led to successful solutions to several issues causing latency. Other problems remain open despite these efforts. This thesis aims to extend our understanding of WiFi networks through the lens of latency and packet loss performance. We approach this using the quality attenuation metric. Quality attenuation is a way of combining latency and packet loss into a single variable. A quality attenuation value consists of a latency distribution combined with the probability of packet loss. The thesis begins by investigating which performance issues are most prevalent in today's WiFi networks. We show that both queuing latency and the WiFi protocol specification itself are significant contributors. By building a model of the WiFi protocol behavior we quantify the performance of the protocol in terms of quality attenuation. We find that significant performance variability is an inherent consequence of the protocol design. Having quantified how variable WiFi links are, we explore the consequences of this intrinsic variability for the performance of end-to-end congestion control algorithms running over WiFi. Because of the intrinsic variability of WiFi, achieving stable, low-latency networking with WiFi will require innovation on many levels of the network stack. In particular, we prove that capacity-seeking traffic can not achieve both high utilization and low quality attenuation over a typical WiFi network unless WiFi networks become much more predictable than they are today. We hope that the methods and results presented in this thesis will hasten the arrival of the low-latency Internet. Best regards, -- Bjørn Ivar Teigen Head of Research +47 47335952 | bj...@domos.no | www.domos.no ___ Bloat mailing list Bloat@lists.bufferbloat.net https://lists.bufferbloat.net/listinfo/bloat
