Samsung Ubigate iBG3026, Configuration Manual

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CHAPTER 30. Analog Voice Port
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© SAMSUNG Electronics Co., Ltd.
Analog E & M Interface
Analog E & M Interface
Analog E&M interface, which uses special signaling paths that are separate
from the trunk’s audio path to convey information about the calls.
The signaling paths are known as the E-lead and the M-lead. The name E&M
is thought to derive from the phrase Ear and Mouth or rEceive and transMit
although it could also come from Earth and Magnet.
E & M method, having Answer/Disconnect Message, is preferred to FXS/FXO.
The physical E&M interface is an RJ-48 connector that connects to PBX trunk
lines, which are classified as either two-wire or four-wire. This refers to
whether the audio path is full duplex on one pair of wires(two-wire) or on two
pair of wires(four-wire).
A connection may be called a four-wire E&M circuit although it actually has
six to eight physical wires. It is an analog connection although an analog
E&M circuit may be emulated on a digital line. For more information on
digital voice port configuration of E & M signaling
Immediate-Start Method
Immediate-start is the simplest E & M Access signaling. Calling side hooks
off E-lead to enter ‘seizure’ action, and sends address information. Use DTMF
(dual-tone multifrequency) digits or MF for address information.
Figure 30.4 Immediate method signaling sequence
Originating Destination
M-wire E-wire M-wire E-wire
seizure
digits
digits
answer
Min 70 msec
Max 10 sec
Min 200 msec