E1 -- Digital
transmission facility capable of carrying data rates of 2.048Mbps. Also
known as G.703 - ITU-T. Usually used for access/egress to providers'
premises. May be broken down into 32 channels 64kbps each . The US
Telco's use T1 as the primary digital communications method - also known
as DS1. E1's are usually (but not necessarily) used outside of the US.
E & M (Ear and
Mouth) -- Analogue signaling (primarily
voice) over 4 wire copper. Includes the facilities for Loop Start and
Ground Start. "E & M Signaling" is a voice transmission system using two
pairs. "Ear and Mouth". The "E" is the receive, and the "M" is the
transmit path for analogue signaling
A very common method of networking computers in a