8E1

8E1 is a telecommunications term describing a configuration that carries eight E1 digital transmission signals on a single interface or port. Each E1 provides 2.048 Mbps, so eight E1 channels yield a total payload capacity of 16.384 Mbps. The 8E1 arrangement is commonly implemented in multiplexers, cross-connects, and edge equipment to provide eight tributary lines over one physical connection or module.

Technical background: An E1 signal is a PDH (Plesiochronous Digital Hierarchy) digital transmission format with 32 time slots of 64 kbps. Typically, slots carry 30 B channels for voice or data (slots 1–15 and 17–31) along with framing and signaling in certain configurations. When eight E1 signals are aggregated into an 8E1 interface, the resulting port presents a single 16.384 Mbps channel to the backhaul or to a higher-layer network element, while preserving the individual E1 framing and signaling characteristics on each tributary as managed by the multiplexing gear.

Applications and deployment: 8E1 is used in legacy and some modern telecom networks to consolidate multiple E1 circuits for backhaul, access, or distribution within a central office, aggregation node, or customer premises equipment. It often appears on line cards, mux backplanes, or digital cross-connect systems that must support multiple E1 circuits through a common interface.

See also: E1, PDH, SDH/SONET, ITU-T standards (G.702/G.703), digital multiplexing.