*Notes*
The Adtran 9XX "E Series" (904e/908e/912e/916e/924e) have 4, T1 ports. These ports differ in that the first two are always network facing and the second two can either be network facing or can be used for PRI & E&M wink. Those could indicate a network problem if you have more than 3MB of service or they indicate a customer problem if you have less, as those are where your PBX would go. If a customer has 4.5MB and a PRI, they would be plugged into T1 0/4 more than likely, for example.
*Note that to use a PRI on ports 0/3 and 0/4, you must use a T1 crossover, swapping pairs 1+2 with 4+5.