Interface boards

An interface board, or telephony interface board, is a catch-all term for hardware and installable circuit boards. There are many kinds of interface boards that help different parts of telephony system operate. These include:

There is considerable overlap in function for these boards. A voice board, for example, can sometimes support T.38 fax protocol, and both conference and VoIP boards also support voice. Not all resellers agree on a naming convention, and the names are more based on the need of the business or PBX system in question.

Voice Boards

Voice boards or voice cards are voice processing devices that simulate FXS signals between a computer and a telephone. A voice board can sometimes function as an interface for different communication media, such as fax, along with VoIP.
See more about voice boards.

Fax Boards

Fax boards convert fax signals (digital or analog) into data packets transmittable over an IP network. Fax boards may support a dedicated fax server on a LAN or allow a single computer to receive and transmit fax.

Fax boards, like other interface boards, fit in PCI or PCI Express expansion slots in a computer. Fax boards can be used with analog telephone lines or in combination with software that uses T.38 protocol.

Conference Boards

Conference boards are much like a voice card with support of numerous channels (e.g. 16 members in a conference). The interface creates a conference by cross connecting time slots in its voice channels with that of the selected other channels in a conference stream.

VoIP Boards

VoIP boards can provide the major services required for a VoIP telephone system. A VoIP board will encode, decode, parse, and receive either SIP or H.323 packets. Like voice cards, VoIP boards contain multiple channels for phone system lines and extensions. A VoIP board replaces a PSTN line board in a telephone system.

The number of VoIP boards required for a networked telephone system is equal to the number of nodes (connection point, endpoint, or terminal) in the IP system.

IP Link Boards

IP link boards are a general piece networking system hardware, not necessarily for telephony.
These interface boards allow nodes to communicate at the data-link layer of Internet Protocol. Types of IP links include Ethernets, hubs, and Asynchronous Transfer Mode.


Gateways are used in telephony to communicate with another network that uses a different protocol. VoIP gateways, or media gateways, translate analog to digital data or vice versa and allow an IP PBX to connect to the PSTN. See more about VoIP gateways.

Specific Gateways

Station Interface Boards

Station interface boards assist converged or hybrid communications systems. Station interface boards act as a switch device that connect to analog phone devices. Like many interface boards, a station interface board is installed in a PCI or PCI Express expansion slot.

See also

Created by: jarnold, Last modification: Tue 07 of Feb, 2012 (23:35 UTC) by admin
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