Telephony cards, or telephony boards, are the essential hardware components of telephone systems that integrate with computers (i.e. CTI). Telephony cards are installable circuit boards that usually fit into PCI slots in computers.

A telephony card can perform all the main features of a telephone system. The card can be used for PBX or IVR systems, call recording, dial dictation, DTMF tone detection/generation, analog-VoIP conversion, etc.

Cards are made to support analog, digital or hybrid phone systems. Both FXS and FXO ports are available, depending on the model. Ports usually range from 2-32, though there are boards with a much higher number of ports.

Telephony boards have functions that overlap with voice boards and other interface boards. The naming convention is not clearly defined. Unlike VoIP boards, however, telephony boards are not limited to digital signals or IP framework and can work with traditional systems--such as T1--needing CTI.

There are many combinations of features available for telephony boards, depending on various factors:

• port type (FXS, FXO, Ethernet)
• number of ports
• DSP vs HMP processing
• expansion slot type

As with other interface boards, telephony cards will work with either Windows or Linux environments (such as Asterisk, which is Linux-based).

Manufacturers of Telephony Cards

• Ai-Logix
• Dialogic
• MUSIC Telecom
• PIKA Technologies
• Sangoma
• Voicetronix

See also

• interface boards
• voice card
• CTI
• PBX