Data is transmitted in packets. Each packet has a packet header, and a packet payload. The total data transmitted is the header + payload.
If you’re transmitting smaller packet sizes, it means your header is a larger percentage of the total packet size.
Measuring in megabits is the ISP telling you “look, your connection is good for X amount of data. How you choose to use that data is up to you. If you want more of it going to your packet headers instead of your payload, fine.” A bit is a bit is a bit to your ISP.
The real answer?
Data is transmitted in packets. Each packet has a packet header, and a packet payload. The total data transmitted is the header + payload.
If you’re transmitting smaller packet sizes, it means your header is a larger percentage of the total packet size.
Measuring in megabits is the ISP telling you “look, your connection is good for X amount of data. How you choose to use that data is up to you. If you want more of it going to your packet headers instead of your payload, fine.” A bit is a bit is a bit to your ISP.