I have two computers:
- (B) Banana Pi - 1 Gigabit Ethernet, Wi-Fi (supports 802.11n)
- (D) Desktop PC - 1 Gigabit Ethernet, Wi-Fi (2x2 MIMO, supports 802.11n)
And (R) Mikrotik RouterBOARD RB951G-2HnD - Gigabit Ethernet ports, supports 802.11n.
What suprises me a lot is that huge difference in throughputs (using iperf to test):
Scenario 1
(B eth0) - direct point-to-point Ethernet connection - (D eth0)
(D) > (B): ca. 850 Mbps
(B) > (D): ca. 800 Mbps
Scenario 2
(B eth0) - connected via (R), static addressing, i.e. (R) serving as a switch - (D eth0)
(D) > (B): ca. 800 Mbps
(B) > (D): ca. 500 Mbps
Scenario 3
(B eth0) - connected via (R), DHCP from (R) - (D eth0)
(D) > (B): ca. 800 Mbps
(B) > (D): ca. 450 Mbps
Scenario 4
(B wlan0) - connected via (R), DHCP from (R) - (D eth0)
(D) > (B): ca. 25 Mbps
(B) > (D): ca. 25 Mbps
Scenario 5
(B wlan0) - connected via (R), DHCP from (R) - (D wlan0)
(D) > (B): ca. 12 Mbps
(B) > (D): ca. 12 Mbps
Questions:
- What's happening with (B)'s Tx or (D)'s Rx when connected via (R)? It almost halves (800/450) compared to the direct point-to-point connection (850/800). How can I examine it more in depth or possibly fix it?
- As (R) is 2x2 MIMO with 300 Mbps PHY data rate capability I think the actual 25 Mbps throughput (see scenario 4) is really poor result. (R) is configured as 802.11n only, 40 MHz channel width, using dual chain (MIMO), signal on (B) and (D) is strong.
