Horrible speeds after switching ISPs

[afelah 0]

I recently switched from Comcast cable broadband to CenturyLink fiber over PPPoE.  I used to get decent (~24 Mbps down) speeds when connected to AirVPN while using Comcast, but since switching to CenturyLink my speeds are horrendous.  My most recent speed test showed 2.4 Mbps down and 5.4 Mbps up.  I've tested from multiple computers/operating systems, and I've replaced the CenturyLink router with an enterprise firewall; speed issues are consistent regardless of the equipment I'm using.  The problem is the same regardless of the server I connect to or the protocol that I use.

 

I'm aware that the MTU is lower over PPPoE than standard Ethernet, and via testing have determined that outbound pings from my computer fail if the size is greater than 1464 bytes (pinging directly from my firewall confirms that the MTU on that end is 1492 bytes, as I'd expect from PPPoE).  I've accordingly set the "mssfix 1424" OVPN directive in my AirVPN client properties, but this doesn't seem to have had any effect.  I've tried a variety of other MSS sizes, and also tried using the "mtu-test" and "tun-mtu" directives, but again, no joy.

 

So what should I try next to get decent speeds again?  Has anyone else run into this problem?

 

 

Results of speed test from AirVPN site, for reference:

Down: 3.025 Mbit/s Out, 2.127 Mbit/s In (70%), 20MB - Up: 5.965 Mbit/s Out, 5.580 Mbit/s In (93%), 20MB - Date: Sat, 26 Mar 2016 23:19:35 GMT - Buffers: 20MB/20MB - Laps: 3, Time: 292.55 secs

 

[Staff 10016]

Hello,

 

please make sure to not modify tun-mtu size, it must remain consistent with the server settings.

 

Have you already tested lower mssfix values, even as low as 1300 and also ruled out any possible UDP capping from your corporate firewall and/or any other tool in your network and system?

 

If so, try an "OpenVPN over SSL/TLS" connection. It will add remarkable overhead (double tunneling, OpenVPN forced to work in TCP...) but if your ISP is performing traffic shaping against OpenVPN that's higher than the additional overhead, you might get a net performance gain, even a substantial gain.

 

You can change connection mode in the Air client window "AirVPN" -> "Preferences" -> "Protocols".

 

Kind regards

[zhang888 1066]

Centurylink is a known "bad" and traffic shaping (throttling) ISP.

You should try the suggestion of Staff above, and if this still doesn't work, which might not since a few years ago the ISPs used simple

QoS rules on top of all their customers, today unfortunatelly, from the place where I see it, while working with many global ISPS, it became

a total unregulated mess. Because the traffic demand grown up by a magnitude - thanks to all new gadgets and video/chatting services,

ISPs didn't quite adjust to this yet. So while paying the same amount of money you used to pay, say, 3 years ago, our ISPs now spend ~3

times more money just to keep up with the bandwidth demands. I don't try to defend this policy but working in my past in various ISPs I can

understand where this is coming from. Only the biggest/notorious ones will survive. Smaller one's like Century are simply left with no much of

a choice but serving the best they can, for the broader public they have. And this is the way many ISPs are doing in places where a large traffic

consumer pays less than an ISP can make profit of this customer. Unless many monopolies will break, along the years, not many is expected to change.

 

A CenturyLink subsciber recently uploaded a video where he uses a VPN to bypass their throttling, you might want to watch it and try different

connection methods to AirVPN: youtube.com/watch?v=dh9cI-j0B6c

 

Fortunatelly, there are still somewhat honest ISPs in many countries, and in U.S. as well. I will not recommend any, but with trial and error

you will find a good one for sure.

[go558a83nk 364]

you can try turning off mssfix altogether in the custom openvpn config section "mssfix 0" (that's zero).  but, most likely you'll have to do what staff said and use the SSL tunnel.

[afelah 0]

Thanks for the quick response!  Good to know about the tun-mtu size parameter.

 

I was the one who configured the enterprise firewall, and it's definitely not capping UDP.  I also get the same results when connecting via TCP, so that rules out a UDP-based issue.

 

I'll experiment some more with different mssfix sizes; at first setting the value down to around 1200 seemed to produce good results, but on repeat trials the numbers were just as bad as before.  I had already tried every one of the different protocol options (yes, all of them), but haven't combined those with the lower mssfix values.  At first glance it seems like the combination of mssfix 1200 and the SSL tunnel produces no better results than I've been seeing with my previous configurations.

 

In the end, I just may need to call CenturyLink and make angry noises at them...  Though I don't expect that will accomplish much of anything, which is why I'm asking here first.

 

Hello,

 

please make sure to not modify tun-mtu size, it must remain consistent with the server settings.

 

Have you already tested lower mssfix values, even as low as 1300 and also ruled out any possible UDP capping from your corporate firewall and/or any other tool in your network and system?

 

If so, try an "OpenVPN over SSL/TLS" connection. It will add remarkable overhead (double tunneling, OpenVPN forced to work in TCP...) but if your ISP is performing traffic shaping against OpenVPN that's higher than the additional overhead, you might get a net performance gain, even a substantial gain.

 

You can change connection mode in the Air client window "AirVPN" -> "Preferences" -> "Protocols".

 

Kind regards

[go558a83nk 364]

what operating system are you running openvpn on?  If linux you might try "mtu-disc yes" or "mtu-disc maybe".  don't forget to try "mssfix 0" in combination with mtu-discovery.

 

Also, have you tried different send and receive buffers since changing ISP?