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 v0.3.0 (protocol version 1, libsodium 1.0.7)

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 --crypto METHOD 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)	835 Mbits/sec	90% / 100%

Latency

The latency is measured with the following command:

$> ping DST -c 100000 -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	164 µs	171 µs
Unencrypted VpnCloud	217 µs	227 µs	242 µs
Difference	+59 µs	+63 µs	+71 µs
Encrypted VpnCloud (ChaCha20)	231 µs	245 µs	259 µs
Difference	+14 µs	+18 µs	+17 µs
Encrypted VpnCloud (AES256)	223 µs	237 µs	251 µs
Difference	+6 µs	+10 µs	+9 µs

Conclusion

• VpnCloud achieves over 850 MBit/s with default MTU settings.
• In encrypted mode, VpnCloud reaches over 800 MBit/s with default MTU settings.
• VpnCloud adds about 70µs to the latency.
• Encryption adds an additional latency up to 20µs depending on the packet size.