What Are The Requirements For Telephone Service - Cisco DPC2420 User Manual

Installation Preparations

What Are the Requirements for Telephone Service?

If you intend to use the residential gateway for digital telephone service, verify that
your home meets or exceeds all of the following requirements.
Maximum Number of Telephones
The RJ-11 telephone-style connectors on the residential gateway can each provide
telephone service to multiple telephones, fax machines, and analog modems.
The maximum number of telephone devices connected to each RJ-11 port is limited
by the total Ringing Load of the telephone devices that are connected. Many
telephone devices are marked with a Ringer Equivalent Number (REN). Each
telephone port on the residential gateway can support up to a 5 REN load.
The sum of the REN load on all of the telephone devices attached to each port must
not exceed 5 REN.
Telephone Device Types
You can use telephone devices that are not labeled with a REN number, but the
maximum number of attached telephone devices cannot be accurately calculated.
With telephone devices that are not labeled, each device should be connected and
the ring signal should be tested before adding more devices. If too many telephone
devices are attached and the ring signal can no longer be heard, telephone devices
should be removed until the ring signal works properly.
Telephones, fax machines, and other telephone devices should use the center 2 pins
of the RJ-11 connectors to connect to the residential gateway telephone ports. Some
telephones use other pins on the RJ-11 connectors and require adapters in order to
work.
Dialing Requirements
All your telephones should be set to use Dual-Tone Multi-Frequency (DTMF)
dialing. Pulse dialing is typically not enabled by your local provider.
Telephone Wiring Requirements
The residential gateway supports connecting to the interior telephone wiring as well
as connecting directly to a telephone or fax machine. The maximum distance from
the unit to the most distant telephone device must not exceed 1000 feet (300 meters).
Use 26-gauge twisted-pair, or larger, telephone wiring.
Important: Connection to an existing or a new permanently installed home
telephone wiring network must be done by a qualified installer.
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