isp speed

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dgermann
OpenVPN User
Posts: 32
Joined: Wed Feb 13, 2013 1:33 am

isp speed

Post by dgermann » Sat Mar 04, 2017 10:04 pm

Friends--

My openvpn has worked well for the last 2 years with a particular remote client, and recently has been having keyboard lag as the primary issue. I suspect the issue is the client's isp speed. The question: if it is reasonable to suspect the isp speed, what speed do we need to tell the isp we need as ideal (which of course I will tell isp is our minimum).

Production environment.
Server ubuntu 14.04 lts; openvpn version 2.3.2
Client ubuntu 12.04 lts to start, then upgraded to 16.04.2 with 4.8.0-39-generic kernel; openvpn version 2.3.10
Work done is primarily LibreOffice 5.1 writer and calc documents.
The issue usually shows up as the screen lagging the keyboard by 3 to 5 seconds; when a menu item (file, edit, view, etc) is pressed the whole thing locks for 10 to 30 seconds at a time. This is not every time.
The problems started becoming noticeable when the switch was made from 12.04 to 16.04. Had not paid attention to isp speed before that. We switched isp providers, and if anything the problem became worse.

Tests done: Tried libreoffice writer and calc on a fast connection (ran speedtest.net on this connection, consistently getting readings like 29.83 Mbps), and did not have issues. Tried the same kinds of documents on the local hdd, and there was likewise no lag.

Using the isp at the client location (about 20 miles away from the server), we are getting inconsistent speeds from 11.45 to 18.43. We can run the test several times in a few minutes and get 15.25, then 16.3, the 14.63, then 11.45. All over the place, up and down. This is where we get the lag.

So I decided to throttle the client machine in the faster environment. I ran

Code: Select all

sudo tc qdisc add dev enp2s0 root netem delay 200ms
on the client machine, and the speedtest results dropped from 28.304 to 22.74. Then ran some tests on the client machine: on documents stored on the server the problems showed up. On documents stored on the client's local drive, there was no keyboard lag.

So:

1. Do you agree this seems to be an isp speed issue, or should I look elsewhere?
2. What speed is optimal for our needs?
3. Are there any things I can put in the conf files that will help speed?

Thanks!

:- Doug.

brendan
OpenVPN Power User
Posts: 104
Joined: Wed Oct 19, 2011 1:19 am

Re: isp speed

Post by brendan » Mon Mar 06, 2017 6:16 pm

first, QoS will be ineffective unless your link is saturated. second, QoS will likely be ineffective because you dont control both ends, and therefore are likely not setting the same QoS policy on both sides of the link. i did a bunch of research into QoS when i started streaming and cut my cable tv. i talked to guys on the lan/wan team that manage the QoS on our network, and they gave me quite a bit of info. they artificially congest the MPLS links we have to force QoS to work, and then do a bunch of policing. those two tidbits are the relevant details here.

what you are likely seeing is packet loss or high latency on your ISP link. the jitter causes VPN traffic to freeze, stutter etc. if it gets bad enough, the connection will drop. check your ISP link and router for errors, dropped packets, packet loss, and run some latency test. also check lan side connections, and make sure there are no issues with the openvpn server and traffic getting to/from it.

dgermann
OpenVPN User
Posts: 32
Joined: Wed Feb 13, 2013 1:33 am

Re: isp speed

Post by dgermann » Sat Mar 11, 2017 9:07 pm

brendan--

Thanks for helping me. Sorry you had to wait for a response, the forum did not notify me of your reply.

On the server I have an archer c7 router, and as far as I can tell, there is no QoS setting on that. Don't know what router they have on the client side.

You are out beyond the edge of my understanding of networking.

I just enabled statistics on the server side router. For what should I be looking?

How do I check my isp link? Are there log files for the server and the traffic to and from it? Not sure what to check. Do you have a simple latency test you like--I just googled and there are a whole bunch! Just tried iperf3 but even opening the firewall on 5201 it says Connection refused.

Does it make a difference that everything was working fine till a couple weeks ago, about the time client got a new isp? We are getting speedtest -cli results on the client of downloads around 4.60 Mbit/s.

Thanks, brendan!

brendan
OpenVPN Power User
Posts: 104
Joined: Wed Oct 19, 2011 1:19 am

Re: isp speed

Post by brendan » Sun Mar 12, 2017 1:40 pm

i run a very advanced config on linux as my router, so i dont know what metrics you are able to see on a consumer grade router like the archer c7. if you can run "ifconfig" on it and look at the WAN/ISP interface of the device, any errors, dropped packets, etc will be an indicator of ISP issues.

use DSL Reports to check response time and upload/download speed on both ends, while the tunnel is down. http://www.dslreports.com/speedtest

iperf requires that you run one server instance and one client instance. with the tunnel up, run "iperf -s" for the server, and "iperf -c <host name or ip>" for the client. the man page should help you out.

while the change in ISP could be a factor, you dont have any evidence yet, so it is only a theory. see if you can monitor the ISP connection and establish data to support the idea that the ISP link is faulty and then call support if you get the data.

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