E&M Subscriber Line; E&M Interface; E&M Start Mode - HP FlexNetwork MSR Series Configuration Manual

Figure 8 Network diagram
Perform an automatic busy tone detection test as follows:
1. Dial number 1002 from Telephone A (010-1001). The FXO interface on Router A plays a dial
tone to PBX A, which then transmits the tone to Telephone A. Then dial number 07552001 from
Telephone A. Telephone B rings. After Telephone B is picked up, the call is connected.
2. If you hang up Telephone A, PBX B plays a busy tone to Router A.
3. Use the vi-card busy-tone-detect command in voice view to start the detection. To ensure the
detection of the busy tone signal sent by PBX B, Hewlett Packard Enterprise recommends that
you run the command 2 seconds after on-hook.
4. (The console terminal displays "Begin to autodetect busy-tone, it will take about 12 seconds,
please wait...", which indicates that the busy tone detection is in progress. After the detection,
the terminal displays "Auto-detect busy-tone succeeded!", which indicates that the detection
succeeded.) Use the save command to save the detected busy tone parameters.
5. Repeat step 2 to verify whether the automatic busy tone detection succeeded. If so, Telephone
A will automatically be disconnected after PBX B plays busy tones to Router A for 4 seconds.
E&M subscriber line
E&M interface
An ear & mouth or receive & transmit (E&M) interface uses a RJ-48 telephone cable to connect a
PBX. The PBX sends signals on the M (mouth) line and receives signals on the E (ear) line. The
voice router receives M signals from the PBX and sends E signals to the PBX. An E&M interface can
only be connected to another E&M interface.
When E&M is applied in VoIP communication, two or four voice wires can be used. There are two or
four signaling wires as well. Therefore, 4-wire analog E&M actually has six wires. In two-wire mode,
voice is transmitted over each wire in each direction simultaneously. In four wire mode, voice is
transmitted over each wire pair in each direction simultaneously.
E&M start mode
An E&M interface supports E&M signaling and divides each voice connection into trunk circuit side
and signaling unit side (similar to DCE and DTE).
An E&M interface provides on-hook/off-hook signals with minimum interference. Instead of using dial
tones, E&M interfaces use one of the following main start dial supervision signaling protocols:
•
Immediate start—As shown in
period of time, and sends the dialed digits regardless of whether the called side is ready or not.
If the called side receives the digits, it rings to alert the called party of the call. If the called party
picks up the phone, the call is connected.
Figure 9, the calling side goes off-hook, waits for a certain
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