What is the total length of pure TCP Ack sent over Ethernet?

Question

I took a clean TCP connection using Microsoft Network Monitor. It shows the captured frame length as 54 bytes. IP header (20 bytes) + TCP header (20 bytes) + Src MAC (6 bytes) + Dst MAC (6 bytes) + Frame type (2 bytes). I do not see the CRC field (4 bytes). I know that the minimum frame length for Ethernet is 64 bytes (46 + 18), and the maximum is 1518. Why can't I see this in Network Monitor? The data field value for the Ethernet frame is 46-1500. Is the IP data frame filled with zeros of 6 octets to make the total frame length 46?

The answer was found: the minimum data field length of a packet sent over Ethernet is 46 octets. If necessary, the data field should be supplemented (with zero octets) to match the minimum Ethernet frame size. This padding is not part of the IP packet and is not included in the total length of the IP header field. http://www.ietf.org/rfc/rfc0894.txt

What is the minimum frame overhead in IEEE 802.11. What is the maximum and minimum frame size? What will be the frame size of pure TCP Ack over Wi-Fi?

I will also accept partial responses

Answer 1

Wireshark answers your question in FAQ 7.10 .

FCS Ethernet , , . , , (?) Ethernet- NetBSD , , Apple Gigabit Ethernet Mac OS X; FCS, FCS , ( , ).

---

IEEE Std 802.11 60:

Frame Body . MSDU (2304 ) .

Answer 2

-, ethernet wifi- - ... wifi , 802.11, wifi 74 . , wifi 0 , Ethernet II, 46 .

, wifi TCP ACK...

30-bytes (wifi ethernet hdr)
20-bytes (IP Header)
20-bytes (TCP Header)
 4-bytes (MIC, if WPA)
 4-bytes (CRC)
------------------------
 > 74 bytes

802.11 ( ) 2346 .