Let's say, my image file has a size of 2 megabytes. It is sent over TCP/IP/Ethernet.
I want to know roughly how many IP packets are sent.
The purpose of this example is to get better intuition/understanding.
Ethernet payload: 1500 bytes
IPv4 header: 20 bytes
TCP header: 20 bytes
So, the Maximum Segment Size is 1460 (= 1500 - 20 -20) bytes.
Number of IP packets:
2,000,000 bytes / 1,460 bytes = 1,369.86...
So, 1370 IP packets are sent.
The maximum possible IP packet size is 65,535 bytes. If fragmentation is used in the Ethernet header, the number of IP packets could be lower.
Alternative size of IP packet: 60,000 bytes
2,000,000 / 60,000 = 33.33...
In this case, 34 packets would be sent. However, there would be computation overhead for fragmentation, because Ethernet only accepts a payload of 1,500 bytes.
I would have expected way fewer IP packets for an image file.
Which of the two calculations is more reasonable?