DUS 31¶

The DUS 31 is the first digital unit (we know) which supported multi-standard on the same DU. As you can run both LTE and GSM on the same unit, it basically combines a DUL and a DUG.

The GSM back-haul is no longer exposed via E1/T1 TDM lines, but uses Ericsson PacketAbis over IP, which is basically the L2TP/HDLC based protocol stacking that the SIU 02 or the TCU would have traditionally generated.

Mass Storage¶

The unit has an internal 8GB USB Mass Storage device, as a Micron Embedded USB Mass Storage Drive (e230). You can think of it as a USB thumbdrive, but not with an exterenal USB A plug, but with a 9-pin 2-row 2.54mm pitch receptacle, which can be plugged directly onto USB 2.0 headers on mainboards.

The partition table looks as follows:

Disk ./dus31.dd: 7.56 GiB, 8120172544 bytes, 15859712 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x00000000

Device      Boot   Start      End  Sectors   Size Id Type
./dus31.dd1            4  1999999  1999996 976.6M 21 unknown
./dus31.dd2      2000000 13999999 12000000   5.7G 21 unknown