Open VPN download speed drop problems ASUS RT-AC68U

[Maverick2141]

OK, so I'm kind of new at this, but I've got a weird problem I've been struggling with for over a week now. For the past year, I've been using Air VPN with my Home setup. My ISP is Centurylink using an Actiontec Modem /Router. This router is what most of my family uses.....all the household tv's, phones, tablets, bluray players, etc. I use the WAN/LAN port to connect to my ASUS RT-AC68U Router that I have the latest Asus Merlin FW. I've been paying Centurylink for 40 Mb/s for the past year. Out of their router my download speeds have been running about 40 Mb/s, upload speeds at 5 Mb/s. This is normal for my area. The Asus router running open VPN has been about 18 Mb/s download and the same 5 Mb/s upload. These numbers are liveable for what I do. I use between 2- 3 hardwired ethernet connections, and one wireless connection...my own cell phone off the Asus router. Everything has been great, but I've got so many devices, that I was beginning to have bandwidth issues at peak times of the day. So, in my infinite wisdom, I called Centurylink up, and increased my package to 80 M/bs. The extra speed off their router is great....70 Mb/s download, and about 20 Mb/s upload. Life is good, nobody has issues anymore.....except me. The Asus RT-AC68U router, with double the speed from my ISP dropped download speeds to 6-7 Mb/s. Uploads went up beautifully, to the 16-17 Mb/s range. How can this be? Centurylink Support blames the VPN service. Air VPN blames the CPU's processing power. ASUS support blames the CenturyLink Modem/Router combo, says I need to put it in bridge mode (which I did, the numbers were identical). If I turn off the open VPN in the Asus Merlin FW, the speeds are way up there, the same as the centurylink router (70 Mb/s down, 20 Mb/s up) If I use Air VPN's computer software, the numbers are about what I was expecting from the Asus Router (approx 40 Mb/s down and 20 Mb/s up) But then I have these other devices that I want to use the VPN service on, and they are not computers that I can load the software on. The big question of course, is why did only the download speeds drop so drastically, when my ISP speed doubled. I have overclocked the Asus to 1 Ghz. No change. Anybody got any ideas? between Centurylink, Air VPN, and Asus support, I have tried many things, and nothing has made a difference. Getting kind of wordy here, so I'll quit for now. Thanks everybody.

 

[CaptainSTX]

OK, so I'm kind of new at this, but I've got a weird problem I've been struggling with for over a week now. For the past year, I've been using Air VPN with my Home setup. My ISP is Centurylink using an Actiontec Modem /Router. This router is what most of my family uses.....all the household tv's, phones, tablets, bluray players, etc. I use the WAN/LAN port to connect to my ASUS RT-AC68U Router that I have the latest Asus Merlin FW. I've been paying Centurylink for 40 Mb/s for the past year. Out of their router my download speeds have been running about 40 Mb/s, upload speeds at 5 Mb/s. This is normal for my area. The Asus router running open VPN has been about 18 Mb/s download and the same 5 Mb/s upload. These numbers are liveable for what I do. I use between 2- 3 hardwired ethernet connections, and one wireless connection...my own cell phone off the Asus router. Everything has been great, but I've got so many devices, that I was beginning to have bandwidth issues at peak times of the day. So, in my infinite wisdom, I called Centurylink up, and increased my package to 80 M/bs. The extra speed off their router is great....70 Mb/s download, and about 20 Mb/s upload. Life is good, nobody has issues anymore.....except me. The Asus RT-AC68U router, with double the speed from my ISP dropped download speeds to 6-7 Mb/s. Uploads went up beautifully, to the 16-17 Mb/s range. How can this be? Centurylink Support blames the VPN service. Air VPN blames the CPU's processing power. ASUS support blames the CenturyLink Modem/Router combo, says I need to put it in bridge mode (which I did, the numbers were identical). If I turn off the open VPN in the Asus Merlin FW, the speeds are way up there, the same as the centurylink router (70 Mb/s down, 20 Mb/s up) If I use Air VPN's computer software, the numbers are about what I was expecting from the Asus Router (approx 40 Mb/s down and 20 Mb/s up) But then I have these other devices that I want to use the VPN service on, and they are not computers that I can load the software on. The big question of course, is why did only the download speeds drop so drastically, when my ISP speed doubled. I have overclocked the Asus to 1 Ghz. No change. Anybody got any ideas? between Centurylink, Air VPN, and Asus support, I have tried many things, and nothing has made a difference. Getting kind of wordy here, so I'll quit for now. Thanks everybody.

Look at your CPU utilization. With a higher speed from your ISP your router uses more CPU cycles handling the through put and has less power available to handle the VPN encryption. You will need a more powerful router and at this time the ASUS AC86 fills that position because of its faster processor that supports AES-NI.

 

[MichaelCG]

Unless there is other traffic on the ASUS router keeping the CPU busy, it should not have slowed down with the upgrade. Before the upgrade, the router was already CPU bound on the VPN and was not pegging out the Internet connection. So after the upgrade, the extra bandwidth should have no impact to the VPN.....unless there was other non-VPN traffic that was now free to flow. Unless......the speedtest method being used is doing upload and download tests at the same time. The uploads are no longer choked at 5Mbps...however the drop to sub-10Mbps is just wonky in general.

 

[Maverick2141]

I have absolutely no problem upgrading to the AC86, if I was sure it would work, but the thing is, I can monitor the CPU speed usage while performing the speed test, and during download, where my problem lies, usage only reaches 20% in core 2....briefly. In the upload test, which is fine, both cores go up, with core 2 approaching 50%. It just seems like there is a setting somewhere that is creating a bottleneck, that I'm overlooking.

Also, I have shut down everything else on the Asus AC68 router while doing these tests and troubleshooting, so there is no other traffic. Sppedtest is with Ookla, and as you all know, it first does the download, then the upload tests.