On Fri, 18 Mar 2016 13:25:04 -0600 (MDT) "John L. Ries" <jr...@salford-systems.com> wrote:
> Forgot to mention: > > I use NetworkManager on the main box to configure the connection with > the NAS (if you're using something else, consult your documentation). > Under "IPv4 settings" (or IPv6 if you prefer), select "Link-local only" > as the method. We expect that the NAS will do this automatically when > it finds out the connection is point to point. Thanks. > On Friday 2016-03-18 12:44, John L. Ries wrote: > > >Date: Fri, 18 Mar 2016 12:44:30 > >From: John L. Ries <jr...@salford-systems.com> > >To: Celejar <cele...@gmail.com> > >Cc: debian-user <debian-user@lists.debian.org> > >Subject: Re: Throughput riddle > > > > I don't know if it will help, but I hook up my Iomega NAS directly to my > > desktop machine with a regular cat 5/6 cable (each has two gigabit > > Ethernet ports, so each can connect to the rest of my network, as well > > as to each other) and that seems to help the throughput by a lot (but I > > don't have any numbers for you). So if your NAS has an extra Ethernet > > port, you might want to hook it up to your laptop when you're in the > > same room with it and use your wifi interface to connect to your > > network. Certainly, you should avoid connecting to your NAS over wifi > > if you're using it heavily, as that will definitely slow things down (it > > seems that a lot more handshaking is required to connect through the air > > than through a physical cable). > > > > --------------------------| > > John L. Ries | > > Salford Systems | > > Phone: (619)543-8880 x107 | > > or (435)867-8885 | > > --------------------------| > > > > > > On Friday 2016-03-18 10:48, Celejar wrote: > > > >> Date: Fri, 18 Mar 2016 10:48:24 > >> From: Celejar <cele...@gmail.com> > >> To: debian-user <debian-user@lists.debian.org> > >> Subject: Throughput riddle > >> > >> Hi, > >> > >> I'm trying to understand the throughput across the different links of > >> my little home network, and am perplexed by the measured wireless > >> throughput. > >> > >> The three main devices I'm interested in: > >> > >> Router: Buffalo WZR-HP-G300NH running OpenWrt (Chaos Calmer 15.05). > >> Gigabit WAN and LAN, 802.11bgn wireless. > >> > >> https://wiki.openwrt.org/toh/buffalo/wzr-hp-g300h > >> > >> Laptop: Thinkpad T61 running Jessie 8.3. Gigabit ethernet, 802.11abgn > >> wireless. > >> > >> NAS: Seagate GoFlex Net [STAK100] runninng Debian Jessie 8.3. > >> > >> https://archlinuxarm.org/platforms/armv5/seagate-goflex-net > >> > >> All throughput measurements taken with iperf (run three times and using > >> the median result), unless specified otherwise. These first results are > >> with the laptop connected to the router via cat5: > >> > >> Laptop - NAS: ~874 Mbps. > >> > >> I suppose this is close enough to the gigabit theoretical max, and there > >> isn't > >> any significant bottleneck. > >> > >> Router - NAS: ~217 Mbps > >> Router - laptop: ~198 Mbps > >> > >> Here the router CPU is apparently the bottleneck (top shows close to > >> 100% CPU utilization by iperf for at least part of the 10 second iperf > >> runs). I suppose that this is due to the bits needing to be copied out > >> of the kernel networking stack into iperf's userspace memory, or > >> something like that. I don't understanding why the NAS seems to be > >> doing better, but I suppose it could be an artifact of the data. > >> > >> Here's the part that baffles me - these are with the laptop connected > >> to the router wirelessly: > >> > >> Laptop - router: ~11.8 Mbps > >> > >> These numbers actually exhibit significant variance, but they're > >> generally at least this much, and at most about 15-20 Mbps. > >> > >> Laptop - NAS: ~14.7 Mbps > >> > >> Once again, these numbers vary widely, but are in line with the laptop > >> - router numbers. > >> > >> But here's the kicker: Ookla's speedtest (run on the laptop with > >> speedtest-cli) shows 29.01/5.89 (d/u), and this is fairly consistent. > >> I'm paying Comcast for 25/5, and they apparently provision at > >> 31.25/6.25, so I'm getting quite close to the theoretical max, even > >> when the laptop is connected to the router wirelessly. Additionally, > >> various Android phones also get close to the Comcast provisioned max > >> when connecting wirelessly to the router. > >> > >> So the wireless link can apparently push at least 30 Mbps or so, so why > >> are my local wireless throughput numbers so much lower? > >> > >> I was originally using one of the common 1/6/11 channels, and I switched > >> to 3 since I saw a lot of other stations on those channels. This may > >> have resulted in some improvement, but I'm still stuck locally as > >> above. What's the explanation for this - how can I possibly be getting > >> much better throughput to servers tens of miles away than to my local > >> stations? Does iperf somehow work fundamentally differently from > >> speedtest? If so, which is a better representation of actual throughput? > >> > >> Celejar > >> > >> > > > > Celejar
