One of the issues that came up in the conversion from 3 Mbps to 10Mbps Ethernet in the late 70’s was addressing space.
48 bits was proposed, but one of the staff working for Bill Gunning
said apparently: –
“Bill – that is really silly. Do you realises that addressing space is enough to address every grain of sand on the West Coast? Why not just 32 bits?”
Bill then said: –
“Just a sec. This is going to go into silicon, isn’t it?”
“How big is the die?”
– back came the likely size.
“So, how much space does two bytes take up?”
Pause – almost nothing . . .
“So, 48 bits isn’t silly. What would be really silly is running out of address space.”
That was over 40 years ago.
According to Cisco there are probably 26 billion Ethernet connections.
48 bits in decimal is 281,474,976,710,655.
That’s still 10,000 times the number of users.
That is proper engineering and one of the reasons why Ethernet has been so robust.
Compare IPv4 on 32 bits . . .

By Published On: December 21, 2023Categories: News