How to find out network interface speed

[joao177]

I'm using the rtwn firmware. The man pages for "rtwn" doesn't give me a clue . As I know, this can be achieved in Linux via the "iwconfig" command.

Thank you.

[joao177]

This is the output for "ifconfig rtwn0 chan". Please excuse me if I'm being stupid.

rtwn0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
	lladdr b0:c0:90:a2:d5:45
	index 2 priority 4 llprio 3
	groups: wlan egress
	media: IEEE802.11 autoselect (OFDM48 mode 11g)
	status: active
	ieee80211: nwid "Carol Nova" chan 9 bssid d4:6e:0e:cd:aa:50 -52dBm wpakey wpaprotos wpa2 wpaakms psk wpaciphers ccmp wpagroupcipher ccmp
		chan  freq      properties
		   1  2412 MHz  -
		   2  2417 MHz  -
		   3  2422 MHz  -
		   4  2427 MHz  -
		   5  2432 MHz  -
		   6  2437 MHz  -
		   7  2442 MHz  -
		   8  2447 MHz  -
		   9  2452 MHz  -
		  10  2457 MHz  -
		  11  2462 MHz  -
		  12  2467 MHz  -
		  13  2472 MHz  -
		  14  2484 MHz  -
	inet 192.168.0.107 netmask 0xffffff00 broadcast 192.168.0.255

[J65nko]

Your output shows that your adapter is operating in mode 11g. According to https://en.wikipedia.org/wiki/IEEE_802.11g-2003 the maxium throughput for 11g is 54 Mbit/s.

The modulation scheme used in 802.11g is orthogonal frequency-division multiplexing (OFDM) copied from 802.11a with data rates of 6, 9, 12, 18, 24, 36, 48, and 54 Mbit/s, and reverts to CCK (like the 802.11b standard) for 5.5 and 11 Mbit/s and DBPSK/DQPSK+DSSS for 1 and 2 Mbit/s. Even though 802.11g operates in the same frequency band as 802.11b, it can achieve higher data rates because of its heritage to 802.11a.

The OFDM48 mode 11g however seem to indicate 48 Mbit/s.

[jggimi]

The "interface speed" of a Network Interface Connector (NIC) does not directly correlate to the throughput a NIC can produce. Internal data transfer rates can be lower than the interface speed, there is overhead for each frame/packet processed, and there may be retransmissions of frames due to collisions and errors. In addition, WiFi technologies shift interface speeds up and down constantly for error rate management. The 48 Mbit rate shown by ifconfig(8) was the interface speed at that particular moment-in-time.

NIC throughput can be tested with tools such as tcpbench(1).