This NT3H72AA Radio Signal Processor board that was long ago MDed by Nortel.  You may think it would be impossible to find a spare, but TruePulse has them in stock.  We also have the NT3H32AC, NT3H98AF, NT3H6706, NT3H36BC, NT3H71AA and NT3H73AA.

Nortel NT3H72AA

Nortel NT3H72AA

TruePulse stocks all sorts of MDed (manufacturer discontinued) Central Office telecom equipment from Nortel, Alcatel, Lucent, Fujitsu, Tellabs, Carrier Access, and others.  Please challenge us with your most hard to find needs!