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[HELP] Very slow download, while upload is high
Posted: Tue Feb 14, 2017 4:44 pm
by zeropitarr
Hello,
I've installed VPN Server on Ubuntu.
VPN clients: iphone, Windows 8
Network Traffic Speed Test Tool:
without VPN:
Average Throughput in Download Direction | 36,882,029 bps| 36.88 Mbps
Average Throughput in Upload Direction | 4,933,468 bps| 4.93 Mbps
with VPN (L2TP or SSTP or SoftEteher VPN client with Local Bridge or SecureNAT):
Average Throughput in Download Direction | 300,533 bps| 300.53 Kbps
Average Throughput in Upload Direction | 4,792,693 bps| 4.79 Mbps
from VPN server to another server:
Average Throughput in Download Direction | 950,715,379 bps| 0.95 Gbps
Average Throughput in Upload Direction | 921,468,146 bps| 0.92 Gbps
CPU usage max 2%
Any ideas why download is so slow?
Re: [HELP] Very slow download, while upload is high
Posted: Tue Feb 14, 2017 10:51 pm
by zeropitarr
from another server to VPN server via VPN:
Average Throughput in Download Direction | 9,140,777 bps| 9.14 Mbps
Average Throughput in Upload Direction | 905,329,447 bps| 905.33 Mbps
At the same time dstat:
----total-cpu-usage---- -net/total- ---paging-- ---system--
usr sys idl wai hiq siq| recv send| in out | int csw
0 0 100 0 0 0| 0 0 | 0 0 |5686 12k
0 0 99 0 0 0| 597B 1631B| 0 0 | 366 710
0 0 99 0 0 0|6306B 6897B| 0 0 | 514 1242
0 0 99 0 0 0| 13k 14k| 0 0 | 656 1815
6 4 87 0 0 3| 85M 84M| 0 0 |5201 34k
6 4 88 0 0 2| 117M 116M| 0 0 |4836 47k
7 5 86 0 0 3| 114M 114M| 0 0 |5567 45k
6 5 87 0 0 3| 110M 110M| 0 0 |5589 46k
6 3 88 0 0 3| 114M 114M| 0 0 |4772 47k
6 4 87 0 0 2| 114M 114M| 0 0 |5274 47k
6 5 87 0 0 2| 117M 116M| 0 0 |5063 47k
6 5 87 0 0 2| 114M 113M| 0 0 |6064 48k
6 4 87 0 0 2| 114M 114M| 0 0 |5473 44k
6 4 88 0 0 2| 111M 111M| 0 0 |5026 46k
6 5 86 0 0 2| 117M 117M| 0 0 |5187 46k
6 4 88 0 0 2| 117M 116M| 0 0 |4672 48k
6 5 87 0 0 3| 112M 112M| 0 0 |5200 45k
7 5 86 0 0 2| 112M 111M| 0 0 |6414 44k
7 5 87 0 0 2| 117M 116M| 0 0 |4924 48k
2 2 95 0 0 1| 36M 36M| 0 0 |1927 17k
I've made separate tests for upload/download between servers via VPN:
only download
Average Throughput in Download Direction | 88,183,112 bps| 88.18 Mbps
Average Throughput in Upload Direction | 0 bps| 0 bps
only upload
Average Throughput in Download Direction | 0 bps| 0 bps
Average Throughput in Upload Direction | 910,387,042 bps| 0.91 Gbps
Why "Average Throughput in Download Direction" is very low still ?
Re: [HELP] Very slow download, while upload is high
Posted: Wed Feb 15, 2017 10:49 pm
by zeropitarr
**deleted** incorrect statement... download is always very low, compare to upload and non-VPN download
Re: [HELP] Very slow download, while upload is high
Posted: Wed Feb 15, 2017 11:15 pm
by zeropitarr
VPN Server ---- VPN Client
TrafficServer ---- TrafficClient - download ~88Mbps
TrafficClient ---- TrafficServer - upload ~ 8 Mbps
Why?
Re: [HELP] Very slow download, while upload is high
Posted: Thu Feb 16, 2017 12:34 am
by zeropitarr
I've removed Local Bridge on VPN Server.
Then tested connection between VPN clinets: client1<->VPN Server<->client2
Upload and Download were maximum.
So, the problem is with LocalBridge?!
Re: [HELP] Very slow download, while upload is high
Posted: Thu Feb 16, 2017 1:29 am
by highthroughputvpn
<zeropitarr>
What are you using as your traffic load between client and server?
What CPU is your server running?
I ask because I could not get that kind of speed running on very up to date hardware, details at:
http://www.vpnusers.com/viewtopic.php?f=7&t=7270
-----
Test 1: "vpnserver" and "vpnbridge" are Quad core i7-6700K @ 4.00 GHz on each end and with 1 GigE NIC hardware and 1 GigE switch. It appears I can max the tunnel out at ~850/850 Mbps bidirectional throughput. It does not appear to matter at all how many TCP sessions are active.
-----
Re: [HELP] Very slow download, while upload is high
Posted: Thu Feb 16, 2017 1:35 am
by zeropitarr
Q:What are you using as your traffic load between client and server?
A: traffic tool in vpncmd
Q:What CPU is your server running?
A:Intel(R) Core(TM) i7-6700 CPU @ 3.40GHz
...I could not get that kind of speed running on very up to date hardware...
A: I was able to get 0.95Gbps for upload only. Download is terrible
UPDATE:
I was able to achieve UP & DOWN :300-500Mbps by removing Local Bridge and enabling SecureNAT with DisableKernelModeSecureNAT = true.
CPU usage is very high as result =(
Any ideas how to fix Local Bridge ?
Re: [HELP] Very slow download, while upload is high
Posted: Thu Feb 16, 2017 1:47 am
by highthroughputvpn
No, apologies. :(
The async nature of your problem has me scratching my head.
For my traffic load I used the vpncmd tool as well as iperf on other dedicated machines.
iperf_machine----vpnSERVER----vpnBRIDGE----iperf_machine
When I started hammering the connection (iperf client and server on both iperf_machines pointed at each other, up and down, multiple streams) the CPU on both the vpnserver and vpnbridge spiked to 1 core at basically 100%.
I then moved the test to lesser hardware but more cores and throughput dropped to <500 Mbps, but it was always synchronous / even up and down, regardless of final throughput.
[scratches head]
I am even questioning the 0.95 Gbps upload as I could not get that on the bench with equal hardware.
Is "compression" enable anywhere? Compression killed my throughput testing down into the ~125 Mbps range.
Re: [HELP] Very slow download, while upload is high
Posted: Thu Feb 16, 2017 3:01 pm
by zeropitarr
I've found a solution.
I switched to Local Bridge with TAP. (I was using bridge with eth0)
Re: [HELP] Very slow download, while upload is high
Posted: Thu Feb 16, 2017 3:28 pm
by highthroughputvpn
Congratulations, I am glad you found a solution.
What OS are you on?
Thank you!
Re: [HELP] Very slow download, while upload is high
Posted: Thu Feb 16, 2017 3:42 pm
by zeropitarr
ubuntu 16.0.4.1 amd64
Re: [HELP] Very slow download, while upload is high
Posted: Thu Feb 16, 2017 4:31 pm
by highthroughputvpn
Thanks, same.
Re: [HELP] Very slow download, while upload is high
Posted: Thu May 16, 2019 2:06 am
by nakayama
I know this is an old topic, however, I found myself having the same problem and I was scratching my head for a while until realized that my VPS had a funny MTU value of 1986 for eth0 so I changed it to the standard 1500, then I also needed to change the value of MTU on SecureNAT to 1280, only then it worked at perfect speed.
Hope this helps someone else!
A. Nakayama
Re: [HELP] Very slow download, while upload is high
Posted: Wed May 22, 2019 12:09 am
by lawrence.eka
Hello, I have exactly the same situation. Tried to change MTU size to 1280 and gretap0 MTU size to 1500. No improvement. Any suggestion is welcome here. Thanks
Re: [HELP] Very slow download, while upload is high
Posted: Tue Feb 07, 2023 6:51 pm
by qupfer
old threat, but also struggled with this problem.
On my setup, a "double-bridge" setup helped.
I configured SoftEthers local bridge to create a new TAP (named vpn --> linux inerfacename tap_vpn) device (and NOT to bridge to eth0/eno0/whatever).
And with linux system tools, I create a bridge containing eth0 and tap_vpn.
On ubuntu 22.04, I just installed bridge-utils and use this netplan:
Code: Select all
network:
ethernets:
eth0:
dhcp4: no
tap_vpn: {}
version: 2
bridges:
br0:
dhcp4: false
interfaces:
- eth0
- tap_vpn
addresses: [192.168.178.140/24]
nameservers:
addresses: [192.168.178.1]
routes:
- to: default
via: 192.168.178.1
Nice sideeffect. The SoftEther-IP (in my case 192.168.178.140 is now reachable through VPN too)