Apple have released two versions of their new 802.11n Airport Extreme base station.
The first version only had 10/100 ethernet LAN ports, the newer version has 10/100/1000 (ie gigabit) ethernet LAN ports.
The problem arises that though they have different part numbers, MA073LL/A for the original version and MB053LL/A for the newer gigabit model, both models share the same model number, A1143.
So how do you tell the difference?
There are only two ways really.
One on the box the base station came in, the model will be identified by the part number. MB053LL/A means it is the newer model. There is nothing else on the box which mentions gigabit ethernet.
I know when I bought mine from the Apple Store in Birmingham (in the UK) I was quite concerned whether I had the newer model or not, particularly as it had only just come out.
The other way is via the Airport Utility, which can identify if it is a gigabit ethernet model or the older version.
It’s not that clear from the raw model which is which, but if you have the box or you can access the base station via the Airport Utility then you can find out if you have gigabit ethernet or not.
For other Airport base stations I have a table on my website which goes through all the differences.