This is a post with low-on-effort bandwidth and latency measurements on a 2x2 MIMO wireless link using 802.11 N and Nv2.
The link used is a point to point ~1km link in the 5GHz band used by the Athens Wireless Metropolitan Network (AWMN).
Later this week I will add a another wireless interface on the other side and use the same hardware on my side for one more point-to-point link. Then, I will repeat the same measurements.
We are trying to find out how good Nv2 really is.
The Nv2 wireless protocol is a proprietary Time Division Multiple Access ( TDMA ) protocol available on MikrotTik-routerOS systems with Atheros based cards. Ubiquity has a TDMA protocol called airMAX.
RouterOS systems come with a Bandwidth Test Server by default. However, I think that putting the Bandwidth Test Server and the Bandwidth Test Client on other systems `behind` the routers produces accurate results. Especially, when it comes to TCP bandwidth throughput testing using little busy routers.
80cm off-axis --offset-- satellite dishes and double polarization `awmn-nvac` type feeders are used on both sides. One of the routers is a PC and the other router is a MIPS machine (RB433GL). Unfortunately, at this moment the PC router is connected to the iperf server in his LAN using a Fast Ethernet 100Mb/s NIC. Hence, I have to use the Bandwidth Server and the Bandwidth Tester made by MikroTik. Gladly, the Standalone MikroTik Windows Bandwidth Test runs on Linux with Wine and the LAN bottleneck is on the PC router side. The MIPS machine has a Gigabit NIC and it is connected to a Gigabit LAN. The PC router is an x86 at 2673MHz and the MIPS router is a RB433GL at 680MHz.
For the UDP tests I will just use the Bandwidth Servers and Clients on the routers.
For the TCP tests I will use the Bandwidth Server on the PC router and a Bandwidth Client on a PC behind the MIPS router.
PCrouter <-air-> MIPSrouter <-GigabitLAN-> PC-BWclient
Nv2 N - One Client
Latency with Low Amounts of Traffic --no BW tests
From the AP to the Client
$ ping 10.21.241.67 -c 100 PING 10.21.241.67 (10.21.241.67) 56(84) bytes of data. 64 bytes from 10.21.241.67: icmp_req=1 ttl=63 time=2.27 ms 64 bytes from 10.21.241.67: icmp_req=2 ttl=63 time=6.70 ms 64 bytes from 10.21.241.67: icmp_req=3 ttl=63 time=6.27 ms ... 64 bytes from 10.21.241.67: icmp_req=100 ttl=63 time=2.67 ms --- 10.21.241.67 ping statistics --- 100 packets transmitted, 100 received, 0% packet loss, time 99141ms rtt min/avg/max/mdev = 1.610/5.470/9.517/2.111 ms
Latency with Large Amounts of UDP Traffic --while BW testing
From the AP to the Client
$ ping 10.21.241.67 -c 100 PING 10.21.241.67 (10.21.241.67) 56(84) bytes of data. 64 bytes from 10.21.241.67: icmp_req=1 ttl=63 time=16.6 ms 64 bytes from 10.21.241.67: icmp_req=2 ttl=63 time=9.52 ms 64 bytes from 10.21.241.67: icmp_req=3 ttl=63 time=9.02 ms 64 bytes from 10.21.241.67: icmp_req=4 ttl=63 time=5.60 ms ... 64 bytes from 10.21.241.67: icmp_req=100 ttl=63 time=22.2 ms --- 10.21.241.67 ping statistics --- 100 packets transmitted, 100 received, 0% packet loss, time 99148ms rtt min/avg/max/mdev = 4.754/10.402/37.854/4.615 mswhile testing UDP bandwidth

Latency with Low Amounts of Traffic --no BW tests
From the Client to the AP.
$ ping 10.27.224.237 -c 100 PING 10.27.224.237 (10.27.224.237) 56(84) bytes of data. 64 bytes from 10.27.224.237: icmp_seq=1 ttl=63 time=3.42 ms 64 bytes from 10.27.224.237: icmp_seq=2 ttl=63 time=3.06 ms 64 bytes from 10.27.224.237: icmp_seq=3 ttl=63 time=7.85 ms ... 64 bytes from 10.27.224.237: icmp_seq=100 ttl=63 time=5.79 ms --- 10.27.224.237 ping statistics --- 100 packets transmitted, 100 received, 0% packet loss, time 99116ms rtt min/avg/max/mdev = 1.617/4.341/15.546/2.508 ms
Latency with Large Amount of UDP traffic
From the Client to the AP
$ ping 10.27.224.237 -c 100 PING 10.27.224.237 (10.27.224.237) 56(84) bytes of data. 64 bytes from 10.27.224.237: icmp_seq=1 ttl=63 time=5.73 ms 64 bytes from 10.27.224.237: icmp_seq=2 ttl=63 time=2.75 ms 64 bytes from 10.27.224.237: icmp_seq=3 ttl=63 time=6.67 ms 64 bytes from 10.27.224.237: icmp_seq=4 ttl=63 time=10.9 ms ... 64 bytes from 10.27.224.237: icmp_seq=100 ttl=63 time=8.68 ms --- 10.27.224.237 ping statistics --- 100 packets transmitted, 100 received, 0% packet loss, time 99070ms rtt min/avg/max/mdev = 2.752/7.739/24.250/3.273 mswhile running a UDP bandwidth test
> /tool bandwidth-test protocol=udp direction=transmit address=10.27.224.237 status: running duration: 2m27s tx-current: 205.3Mbps tx-10-second-average: 189.3Mbps tx-total-average: 184.0Mbps random-data: no direction: transmit tx-size: 1500 -- [Q quit|D dump|C-z pause]
Ping while testing TCP bandwidth throughput.
From the client to the AP.
$ ping 10.27.224.237 -c 100 PING 10.27.224.237 (10.27.224.237) 56(84) bytes of data. 64 bytes from 10.27.224.237: icmp_seq=100 ttl=63 time=3.83 ms ... 64 bytes from 10.27.224.237: icmp_seq=100 ttl=63 time=4.02 ms --- 10.27.224.237 ping statistics --- 100 packets transmitted, 100 received, 0% packet loss, time 99108ms rtt min/avg/max/mdev = 2.726/5.791/21.109/3.734 ms
802.11 N One Client
Latency with `low` amounts of traffic --no BW testing
Client to the AP
$ ping 10.27.224.237 -c 100 PING 10.27.224.237 (10.27.224.237) 56(84) bytes of data. 64 bytes from 10.27.224.237: icmp_seq=1 ttl=63 time=0.934 ms 64 bytes from 10.27.224.237: icmp_seq=2 ttl=63 time=0.664 ms 64 bytes from 10.27.224.237: icmp_seq=3 ttl=63 time=0.572 ms ... 64 bytes from 10.27.224.237: icmp_seq=100 ttl=63 time=14.0 ms --- 10.27.224.237 ping statistics --- 100 packets transmitted, 100 received, 0% packet loss, time 99029ms rtt min/avg/max/mdev = 0.486/1.043/15.114/1.977 ms
Latency with large amounts of UDP traffic
Client to the AP
$ ping 10.27.224.237 -c 100 PING 10.27.224.237 (10.27.224.237) 56(84) bytes of data. 64 bytes from 10.27.224.237: icmp_seq=1 ttl=63 time=12.4 ms 64 bytes from 10.27.224.237: icmp_seq=2 ttl=63 time=9.88 ms 64 bytes from 10.27.224.237: icmp_seq=3 ttl=63 time=7.68 ms 64 bytes from 10.27.224.237: icmp_seq=5 ttl=63 time=89.8 ms ... 64 bytes from 10.27.224.237: icmp_seq=100 ttl=63 time=45.4 ms --- 10.27.224.237 ping statistics --- 100 packets transmitted, 89 received, 11% packet loss, time 99089ms rtt min/avg/max/mdev = 7.688/42.859/141.709/16.173 mswhile testing UDP bandwidth throughput
/tool bandwidth-test protocol=udp direction=receive address=10.27.224.237 status: running duration: 2m51s rx-current: 207.5Mbps rx-10-second-average: 200.0Mbps rx-total-average: 108.7Mbps lost-packets: 2308 random-data: no direction: receive rx-size: 1500
With one client to the AP Nv2 increases the latency on the link when there is not traffic but behaves well --in terms of latency-- when we stress the link using a bandwidth tester.
Hmm, Nv2 seems better already ... more tests by me , hence suffering ( sorry ) for the West and South West Athens Neighborhoods are coming.
References:
MikroTik Nv2
2x2 MIMO nv2 measurements