WebSTAR DPC2223 and EPC2223 VoIP Cable Modem User’s Guide Preliminary Draft 02 – 1/26/06
32
What Are the Requirements for Telephone Service?
This section provides hardware and software requirements for utilizing your cable modem for telephone service.
Number of Telephone Devices
The RJ-11 telephone-style connectors on the cable modem 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 cable modem 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 additional 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 cable modem 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 DTMF dialing. Pulse dialing is typically
not enabled by your local provider.
Telephone Wiring Requirements
The cable modem is designed to support interior telephone wiring. 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.
