Hello,
I am currently trying to implement a simple network on the virtual box (version: 6.1). I have three machines where one of them is used as an OpenWrt router (version: 19.07.7) and the other two are Linux (Ubuntu 20.04.2). The OpenWrt router is connected to the Internet (Wifi modem). Linux 1 is connected to the OpenWrt and Linux 2 is connected to the Internet (Wifi modem). Therefore, my setup looks like this:
The speed of the three links in the figure is the same and is set to 1000 Mbps. Using Nuttcp, I generate synthetic traffic from Linux 1 to Linux 2 that goes through link 1, link 2, and link 3. When I run full speed Nuttcp without limiting the bandwidth, the generated traffic has a bandwidth around 1600-1700 Mbps (See below).
baharin@baharin-virtualbox:-$ nuttcp -i1 -N10 -T60 -c0 192.168.0.21
162.8125 MB / 1.00 sec = 1365.7183 Mbps
192.0625 MB / 1.00 sec = 1610.0535 Mbps
205.5625 MB / 1.00 sec = 1724.5471 Mbps
199.5000 MB / 1.00 sec = 1674.1635 Mbps
185.5000 MB / 1.00 sec = 1556.2533 Mbps
186.8750 MB / 1.00 sec = 1576.1995 Mbps
217.3750 MB / 1.00 sec = 1822.9924 Mbps
195.1875 MB / 1.00 sec = 1638.2262 Mbps
204.1250 MB / 1.00 sec = 1711.7221 Mbps
216.1250 MB / 1.00 sec = 1813.0133 Mbps
208.8125 MB / 1.00 sec = 1752.3349 Mbps
197.5625 MB / 1.00 sec = 1656.1151 Mbps
216.4375 MB / 1.00 sec = 1816.0852 Mbps
215.3125 MB / 1.00 sec = 1806.9040 Mbps
I was wondering why the bandwidth of the generated traffic is more than the speed of the links?
The setup is on Dell XPS 13 Laptop. The Wifi adapter is Killer (R) Wi-Fi 6 AX1650s 160 MHz Wireless Network Adapter and the type is Intel PRO/1000 MT Desktop (82540EM).
Any hints on this would be greatly appreciated.
Thanks,
Baharin