Im pretty certain these are the 'NTEs' for leased lines which demux several lines and combine the bandwidth in a similar way which SDSL and even ADSL can be bonded to provide a higher bandwidth.
Going back about 10yrs, 2Mbps was the standard leased line speed and it wasnt unusual for organisations to purchase multiple links if they needed more bandwidth. These boxes will be the kit that 'bonded' the 4 x leased lines so that the company had an 8Mbps connection rather than 4x 2Mbps connections.
2Mbps leased lines were
E carrier circuits, but according to wiki could be multiplexed up to 140Mbps. Multiplexing these E1 leased lines was done over SDH making each E1 line a tributary of the aggregate bandwidth.
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The reason I asked for the date on the sticker is they look similar to the ones in use by our LEA (and other Local Authority Depts) services, who require that all electrical equipment is tested for safety on an annual basis. These stickers should be replaced each year and date on the sticker would tell the last safety check and possibly give an indication of when last in use.
However, Ive just noticed the piper logo - which was last used by BT in 2003 - which could also be an indication of age.
I also believe BT use Cisco rather than Fujitsu NTEs these days for leased lines.
>> Looking around (on eBay), I have found an example of an 'ASDH NTE 16U/7A'
Ive also seen a couple of 36U/7A versions. There seems to be an influx of them atm which makes me think that corporates may be moving on to increased bandwidth via other means ie EFM, newer 1/10Gbps Fibre and even making use of FTTC.
Looking at the example on that rack, the previous owner would likely have had a 32Mbps link installed sometime after 2003 but they retained (some of) their older >8 Mbps either as a fail-over or possibly like what they did at the local college - a separate network for a specific part of the building.