This area is for discussion and information on ESS switching systems, such as
Western Electric 1ESS/1AESS
Western Electric 4ESS
Western Electric 5ESS
Northern Electric SP1
Northern Telecom DMS-10/100
Stromberg-Carlson/Siemens DCO
Siemens EWSD
Automatic Electric C1 EAX
Automatic Electric #1EAX & #2EAX
Automatic Electric GTD5 EAX
And others - a Wikipedia page on ESS:
http://en.wikipedia.org/wiki/Electronic_Switching_System