vpncloud/performance.md

Performance Tests

Test setup

Sender node:

• Intel(R) Core(TM) i5-2540M CPU @ 2.60GHz
• 8 GiB Ram
• Intel 82579LM Gigabit Network
• Ubuntu 14.04 (Kernel 3.13.0-65-generic)
• Libsodium 1.0.7

Receiver node:

• Intel(R) Core(TM) i5-3450 CPU @ 3.10GHz
• 16 GiB Ram
• Realtek RTL8111/8168/8411 Gigabit Network
• Ubuntu 14.04 (Kernel 3.13.0-63-generic)
• Libsodium 1.0.7

VpnCloud version: VpnCloud v0.2.0 (with crypto support, protocol version 1)

The sender runs the following command:

$> ./vpncloud -t tap -l SENDER:3210 -c RECEIVER:3210 \
   --ifup 'ifconfig $IFNAME 10.2.1.1/24 mtu 1400 up' &

and the receiver runs:

$> ./vpncloud -t tap -l RECEIVER:3210 -c SENDER:3210 \
   --ifup 'ifconfig $IFNAME 10.2.1.2/24 mtu 1400 up' &
$> iperf -s &
$> top

For encrypted tests, --shared-key test is appended.

Throughput

The throughput is measured with the following command:

$> iperf -c DST -t 60

The test is run in 3 steps:

• Native throughput without VpnCloud (DST is the native address of the receiver)
• Throughput via VpnCloud (DST is 10.2.1.2)
• Encrypted throughput via VpnCloud (DST is 10.2.1.2)

Throughput test	Bandwidth	CPU usage (one core)
Without VpnCloud	926 Mbits/sec	-
Unencrypted VpnCloud	873 Mbits/sec	80% / 95%
Encrypted VpnCloud (ChaCha20)	770 Mbits/sec	100%
Encrypted VpnCloud (AES256)	813 Mbits/sec	90% / 100%

Latency

The latency is measured with the following command:

$> ping DST -c 10000 -i 0.001 -s SIZE -U -q

For all the test, the best average RTT out of 5 runs is selected. The latency is assumed to be half of the RTT.

Payload size	100 bytes	500 bytes	1000 bytes
Without VpnCloud	158 µs	165 µs	178 µs
Unencrypted VpnCloud	210 µs	216 µs	237 µs
Difference	+52 µs	+51 µs	+59 µs
Encrypted VpnCloud (ChaCha20)	218 µs	230 µs	257 µs
Difference	+8 µs	+14 µs	+20 µs
Encrypted VpnCloud (AES256)	224 µs	230 µs	255 µs
Difference	+14 µs	+14 µs	+18 µs

Conclusion

• VpnCloud achieves over 850 MBit/s with default MTU settings.
• In encrypted mode, VpnCloud reaches over 750 MBit/s with default MTU settings.
• VpnCloud adds about 60µs to the latency.
• Encryption adds an additional latency up to 20µs depending on the packet size.