On-Premises Data Calls: To establish a data connection between an on-premises

analog data endpoint and an on-premises digital endpoint.

Outgoing Trunk Calls: To establish a data connection between an off-premises analog endpoint (modem) and an on-premises digital endpoint.

Considerations

Modem Pooling provides a pool of conversion resources that increases data call flexibility. Conversion resources allow analog data endpoints, using modems, to communicate with digital data endpoints (using data modules). Also, modem pooling reduces costs by sharing resources.

Interactions

Automatic Route Selection: Data calls may be queued. See Table 2-H,“PLEASE WAIT” message.

Calling Restrictions:

If a terminal is toll or access restricted, the modem resource

is released when the user

receives intercept treatment.

Direct Group Calling: Modem pooling supports calls to data endpoints that are part of a DGC group. While an incoming data call is in the DGC group queue, the caller hears Ringback Tone. The conversion resource is inserted if the call is completed to a digital endpoint.

Station Hunting: Modem Pooling supports calls to data endpoints that are part of a station hunting group.

SMDR: SMDR records

do not reflect modem resource usage.

Interpremises data

calls using a conversion

resource are reported as data calls on the

SMDR call record.

Administration Requirements

System (Pooled Modems):

Modem Request Code (l-9999) - Default = 820. Allows users to indicate a need for a

conversion resource on a data call originated at an analog data endpoint.

Receiver Responds To

Remote

Loop (Yes,

No)

- Default

= Yes. When active, Data

Set Ready is asserted

when the

modem is

in an

analog loop

test mode.

Disconnect On Loss Of Carrier (Yes, No) - Default = Yes. When active, a loss of the

received carrier will cause the modem to terminate the call.

CF-CB Common (Yes, No) - Default = Yes. When active, Clear to Send turns off if Carrier Detect turns off. When a call is being established, Clear to Send and Carrier Detect are not allowed to turn on until carrier has been received and the Clear to Send timer has timed out.

Disconnect On Received Space (Yes, No) - Default = Yes. When active, the modem will disconnect after receiving a “Space” signal of approximately two seconds duration.

Send Space On Disconnect (Yes, No) - Default = Yes. When active, the modem, upon receiving a negation of Data Terminal Ready, sends approximately four seconds of “Space” signal and then disconnects. Without this option active, the modem, upon receiving a negation of the Data Terminal Ready signal, disconnects immediately.

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AT&T AT&T manual Calling Restrictions, 165