High Latency

[Naossoan]

Hi all,

I'm having a networking problem.

I'm using a DIR-655 WiFi router, and a Linksys AE2500 dual-band N stick I recently picked up.

I recently moved back to my parents place and there are several wifi clients here.

There is a SMC broadband modem/router combination which was not providing good WiFi signal to me, so I hooked up my DIR-655 to one of it's ethernet ports, disabled the SMC's wifi, and put my DIR-655 on the DMZ for the SMC as to not be dual-routering.

My parents have an exchange student in the house, and I have a feeling something he is doing is causing a lot of latency for me.

My connection to the router is good, usually between a 80-110mbps 4-5 bars connection.

Upon rebooting the router, I will get the usual really good latency, around 20-30 ms. Then after a minute or so, probably after his devices reconnect etc my latency will be ridiculously high, like 1000-2000ms making it impossible for me to play any online games and making browsing the net unbearable. The odd thing is that I have gone into the router and revoked his DHCP lease/connection, dropping him from the router yet my latency will still stay REALLY high, thought not quite as high as before doing this.

What I don't understand is that my parents actual internet connection is a 10mbps connection, so the most he could be using is that, when there is usually 10x that bandwidth available to the router.

Even if he is downloading something, why would it cause actual LATENCY issues with my connection?

I don't know if this is actually being caused by him, or if it is an issue with my USB WiFi dongle or possibly the router. I've used this router at my own place for quite some time and I've never had these kinds of issues with it before, though I was the only one using it but I had several wifi clients as well, so it does lead me to believe whatever he is doing is hogging on the bandwidth.

Is there anything I can do to limit his connection speed/bandwidth as to not make the internet unusable for everyone else?

 

[Naossoan]

OK I know it's definitely something he's doing now. He left upstairs to go make food or something and my latency was fine, around 50 ms. Now he's back in his room and my ms is 500+ ms.

So damn frustrating. I've already talked to him about this and he said he's not downloading anything but that's total BS if this is happening.

I found a QoS section on the router.

I set my IP to be priority 1 for any port/protocol and his IP to be priority 240 (out of 255) for any port/protocol

but this doesn't seem to have any effect.

 

[jlazzaro]

first, there is no need to put the DIR-655 in a DMZ...just don't use the WAN port and disable DHCP. http://www.ezlan.net/router_AP.html

is your latency jumping to 1000ms+ on both WIRED and WIRELESS, or just WIRELESS?

if the problem is just on wireless, check http://forums.anandtech.com/showthread.php?t=264338

if its on wired as well, your really need to know what the cause is in order to stop it. if the exchange student will allow you access to his PC, install NetLimiter or check the process network usage under Windows Resource Monitor. if you can't get access, a packet capture of all your Internet traffic (using Wireshark) would be pretty conclusive.

if the SMC router has any type of BitTorrent blocking, turn it on.

 

[dawks]

Where is the latency you are measuring too? Some remote server? Does your ping to the router vary?

Uploading is the most likely culprit to cause high latency on home asymmetric connections. Try finding an accurate speed for your upload, then configure that in QoS. QoS settings won't have much of an impact on your performance, if uploading is in fact the issue, unless it accurately knows the upload speed limit. It will base its QoS priority's on the amount of know available bandwidth.

 

[Naossoan]

Hi sorry guys I needed some time for testing.

The pinging I'm doing is just to www.google.com in the command prompt. If I ping my router I get no such latency issues from wireless or wired connection.

I tested the pings on my dad's computer with is connected via ethernet to the router and his pings show in the 2000+ range as well, so I guess it's not something related to the wireless.

His PC is also connected to the first device, the SMC router/modem combo deal so I can assume it wouldn't be some internal issue with my DLink DIR655...

Ill see what I can find about bittorrent blockage on both the routers, but I'm pretty sure the DLink doesn't have it. I'd have to know what the ports are that he's using maybe.

Also, my parent's connection is a 10mbit down / 0.5 mbps up connection. Knowing that, how can I configure QoS to work properly?

I guess my other option is to do some packet sniffing with that program you mentioned and use the DLink's access control on the student's connection to only allow regular ports like 80 for HTTP and other stuff like that....but maybe he has some stuff he uses to talk to friends or relatives back home that uses strange ports that I wouldn't really want to block. Just heavy upstream traffic.

 

[ChippyUK]

Hi sorry guys I needed some time for testing.

The pinging I'm doing is just to www.google.com in the command prompt. If I ping my router I get no such latency issues from wireless or wired connection.

I tested the pings on my dad's computer with is connected via ethernet to the router and his pings show in the 2000+ range as well, so I guess it's not something related to the wireless.

His PC is also connected to the first device, the SMC router/modem combo deal so I can assume it wouldn't be some internal issue with my DLink DIR655...

Ill see what I can find about bittorrent blockage on both the routers, but I'm pretty sure the DLink doesn't have it. I'd have to know what the ports are that he's using maybe.

Also, my parent's connection is a 10mbit down / 0.5 mbps up connection. Knowing that, how can I configure QoS to work properly?

I guess my other option is to do some packet sniffing with that program you mentioned and use the DLink's access control on the student's connection to only allow regular ports like 80 for HTTP and other stuff like that....but maybe he has some stuff he uses to talk to friends or relatives back home that uses strange ports that I wouldn't really want to block. Just heavy upstream traffic.

Why don't you say you called your ISP and asked them to investigate. They can say that the cause of this might be due to a virus on one of the client computers. Use that excuse to look at the laptop/computer of the student to confirm the cause of the issue.

It's possible that the person doesn't understand whats causing it.

I think personally it's better to sort this out domestically, but really if he's paying for the line or is included part of the contract that he can use the internet for whatever he wants if the person is insistent.

You could always pay for a second connection if that's what it takes.

 

[dawks]

Hi sorry guys I needed some time for testing.

The pinging I'm doing is just to www.google.com in the command prompt. If I ping my router I get no such latency issues from wireless or wired connection.

I tested the pings on my dad's computer with is connected via ethernet to the router and his pings show in the 2000+ range as well, so I guess it's not something related to the wireless.

His PC is also connected to the first device, the SMC router/modem combo deal so I can assume it wouldn't be some internal issue with my DLink DIR655...

Ill see what I can find about bittorrent blockage on both the routers, but I'm pretty sure the DLink doesn't have it. I'd have to know what the ports are that he's using maybe.

Also, my parent's connection is a 10mbit down / 0.5 mbps up connection. Knowing that, how can I configure QoS to work properly?

I guess my other option is to do some packet sniffing with that program you mentioned and use the DLink's access control on the student's connection to only allow regular ports like 80 for HTTP and other stuff like that....but maybe he has some stuff he uses to talk to friends or relatives back home that uses strange ports that I wouldn't really want to block. Just heavy upstream traffic.

A 0.5mbit upload is very easy to saturate. Thats only 64kbytes/sec. A skype video chat session could max that out, causing a connection to lag. In QoS configuration, there should be a setting to configure your bandwidth speeds, at least upload is normally there. You need to fill in the 512kbits or 64kbytes (depending on what its asking for). This is so the router/QoS knows how many packets it can send at a time. If it hits that limit, then it will begin slowing the sending rate based on the QoS rules configured. Then you'd limit his MAC/IP to a lower priority, or preferably bandwidth limit. Part of the challenge is, if hes uploading, and you're not, his packets will go out at full speed, causing your ping to spike. Limiting on some QoS configurations only limits the uploading relative to other uploading.
A few things to keep in mind.

 

[Naossoan]

Yeah I might have to go toward getting my own connection to the house if my ISP will allow that.

An alternative I have found is something called OpenDNS which he could easily circumvent if he knew anything about computers. All he has to do is manually set his DNS IP address. But anyway I used this service and set it to block p2p/file sharing stuff so hopefully that helps me out. I'll have to wait and see.

Thanks

 

[dawks]

Yeah I might have to go toward getting my own connection to the house if my ISP will allow that.

An alternative I have found is something called OpenDNS which he could easily circumvent if he knew anything about computers. All he has to do is manually set his DNS IP address. But anyway I used this service and set it to block p2p/file sharing stuff so hopefully that helps me out. I'll have to wait and see.

Thanks

Yes, OpenDNS is handy, but easy to get around.

If you have extra hardware around, you could turn a PC into a much more advanced firewall using software like untangle. It doesnt need to be a powerful system, just requires 2 network cards. I actually have my Untangle setup so that you MUST use OpenDNS, any other DNS service is just blocked/dropped. Also untangle has much smarter QoS and bandwidth monitoring/controlling services. If you want even more control, you can pay for some more advanced features and do exactly what you want to do (limit his upstream but not kill his service), with just a few clicks. There are other options like ipcop and stuff, but I'm less familiar with those.

 

[s44]

A 0.5mbit upload is very easy to saturate. Thats only 64kbytes/sec. A skype video chat session could max that out, causing a connection to lag.

Yep, that's happened to me.

QOS should fix your issue... though perhaps not the QOS on your current hardware.

 

[Naossoan]

Yeah this has turned into a bit of a nightmare. The blocking p2p with OpenDNS hasn't seemed to solve the problem, or he's figured out how to get around it, or it's not p2p traffic.

I don't have any computer around, let alone with 2 NIC's that I can use as a firewall.

My DIR655 has a page that shows "full details of active internet sessions to your router." so I should be able to sift through that when my connection is poor to see if I can find out what it is that is causing it.

My assumption is that anything that doesn't use some typical kind of port that a lot of web apps use, like 80, 443 or whatever then it could be something of question.

I look at that list right now and the majority of the sessions are from my PC, with only 3 entries from the computer I suspect is his as the computer name is showing as "apple-a268221c9" and he's got the only mac computer in the house to my knowledge.

Getting to the point now where I just don't give a shit and tempted to just call up my ISP and get another account set up. This benefits me in the way that I can hog up all the bandwidth whenever I want too because it won't affect anyone else.

 

[Dstoop]

This thread seems to have gone way off the rails, with someone going so far as to lieing to the other person to gain access to their PC?

Here's the bottom line, a 10/0.5 connection is absolute crap. He doesn't need to be doing any sort of P2P on that to bring it to a crawl, simply watching SD netflix/youtube or using something like skype is going to nearly saturate that bandwidth.

The best way to solve this is to go right to your housemate, and lay it out straight. Let him know that your connection is totally unusable any time he's doing whatever he's doing up there, and ask him if he'd be willing to sit down and work with you to figure out what he's running that could be causing it. It could be as simple as him going "oh, I didnt realize skype was enough to kill your connection, ill call my family on my cell instead." Spying on his connection with Wireshark or tricking him into giving you access to his PC is pretty damn unethical from both an IT perspective and as a host to an exchange student IMO.

That being said, I have a 25/10 cable connection at home and as a heavy user I sorely miss my 50/25 from before I moved 10/0.5 is like grandma-with-aol level of bandwidth these days, I wouldn't expect a good gaming or browsing experience on that even if I was the only person using it. I'm not sure where you live, but out here the only company that even gives speeds that low is Verizon DSL, which is really glorified dial-up. If you're already contemplating getting your own dedicated line, why not see if they have a much faster package available, or better yet FIOS or cable internet instead?