What I forgot to mention this morning, we had some troubles with these E&M standards. You may want to be careful when you get your hands on an older one.
E & M signaling is signaling where the E stands for Ear and the M stands for Mouth. The TIA PABX standard gave the M requirements for what the PABX was transmitting towards the Central Office, the E requirements for what it was receiving from the central Office. The ATIS interface standard was produced from a Central Office perspective by Bellcore personnel and saw the Ear and Mouth situation the other way around. It did get straightened out eventually, but BEWARE. Ciao, Vic
