E&M interface uses a RJ-48 telephone cable to connect remote calls from an IP network to PBX trunk lines (tie lines) for local distribution. It is a signaling technique for two-wire and four-wire telephone and trunk interfaces.
recEive and transMit (or Ear and Mouth). E&M is a trunking arrangement generally used for two-way switch-to-switch or switch-to-network connections. The Cisco E&M interface is an RJ-48 connector that allows connections to PBX trunk lines (tie lines).
A telephone signaling protocol that uses separate wires for signaling and voice. There are several variations of E&M signaling. A common use of E&M signaling is to connect voice mail and 2-way systems to other switches and devices.
recEive and transMit (or ear and mouth). A signaling technique for two-wire and four-wire telephone and trunk interfaces. One of four common forms of CAS signaling; the others are loopstart, groundstart, and EANA.