Ridiculously bad ping times when *anything* else is using internet

lucernarian

Hi all,

I'm normally able to figure out speed-related issues by myself but I'm thrown by this one. It's been an ongoing problem for a few years on a DSL connection on a long enough line that manages 3 Mbps. Geting ping times of 32 ms to 2140 ms and 15% packet loss with heavy downloading, with other people browsing the net it's more like 32ms to 1500 ms and 5% packet loss. It's noticeable while browsing but actual downloads don't seem to fail or be corrupted despite apparently high packet loss...

I think it's traced to when they had to get a new modem as something broke within the Netopia 2247NWG (I think the power supply) and they ordered a new modem from Vodafone, the HG568C I think. Assuming that's true, since then they've had very unreliable ping times and problems surfing the net when other people are online. They've now bought a TP link TD-W8980 modem/router with more features and Gigabit Ethernet and 802.11n capability but this hasn't made much difference - fewer dropped packets when heavy downloading is going on perhaps.



What I can rule out is any wifi issues - with a wired connection to the router from one computer, the erratic pings and dropped packets appear while there are simultaneous HTTP or bittorrent downloads. I also tried testing with one wired ethernet PC while another wired ethernet laptop was downloading something.

The stats for ADSL2 look a little ropey at 5-6 dB with the HG568c, 6-7 dB with the TP Link and 6 to 8 dB back when they had the Netopia 2247 the last time I was fixing something up for wifi in their house. 0 error count on the TP Link, maybe 500 CRC errors per hour on the netopia and the Vodafone HG568 had maybe 3000 errors of different kinds per hour.

Finally, tracert packets show the problem manifests at the first hop after the router. No dropped packets or weird pings at the 192.168.1.254 address regardless of the kind of test I tried.


Any ideas or suggestions?!

gctest50

lucernarian wrote: »

...They've now bought a TP link TD-W8980 modem/router with

......more features and Gigabit Ethernet and 802.11n capability but this hasn't made much difference .......

all the extra features and Gigabit Ethernet and 802.11n are on "their side" of the modem/router though

its modem may not deal with the iffy line as well as the old one/another one

could always buy another netopia and link it to the TPlink if they are not going to upgrade the lines in the area

10 - 20 euro ish

http://www.adverts.ie/for-sale/q_Netopia+2247/

ED E

The 2247s are slightly better on longer lines, but if you're getting up to profiled speed ok its unlikely to have much beneficial effect.

OP the internet gets heavier month on month, 3Mb is very little bandwidth nowadays. A great example is facebook now autoloading videos in the background, but thats just one example.

Whatever router you put on the end of that PPPoE pipe has to multiplex between all the traffic being pushed in both directions. One or two connections, easy. Add a few more and the wait time between connections being serviced goes up, pings go up.

Strong QoS favouring services you want to will mitigate the problem. A bigger pipe will solve it.

lucernarian

The 2247 might have a better modem chipset (though reports on boards suggested netgears were better) but the SNR margin shouldn't impact on ping times as opposed to lost pings. Basically, after this much troubleshooting I doubt it's an OSI Layer 1 problem but I can't rule it out. There could be an issue with the line as well as with the router or Vodafone. Most of their browsing revolves around RTE, facebook and youtube and maybe the amount of data increases with every year but those websites have been around for years and even now another local has a 1 mbit connection that behaves itself with multiple users.

When they had a 1 mbit connection with the 2247, the internet was consistently kinda slow and if something was downloading, it would be half as slow. But ping times were consistent. Then it was increased to 3 mbps and everything worked better.

But with these much newer routers, why couldn't they manage the routing better than a Netopia 2247? This is what's bothering me. The HG568c had a bizarre behaviour where all pings sent simply timed out at times but on other occasions it worked okay. Normal web browsing worked normally. This even happened after changing wifi passwords and ensuring one device was connected. I have searched on boards but never saw other reports and most people who have the HG568C (Voda VDSL modem/router) seem to be happy with it.

I'm tempted to flash the firmware of the TP link if possible and see where that goes. I am suspecting that http://en.wikipedia.org/wiki/Bufferbloat may be part of the problem but short of simply finding another 2247, I don't know how to fix it