Dumb (but not stupid) telephony cards

This page shows some of the dumb telephony cards which may be used with the software featured on this site. Dumb doesn't have to mean stupid. With the increasing power of host processors, it is now a sensible design option to load far more of the work onto the host processor than previous generations of CTI cards sould realistically do.

Open hardware cards.

The Tormenta 2 T1/E1 telephony card from the Zapata project:

You can find out more about this hardware from www.zapatatelephony.org. Several companies supply this card, such as Varion.

Cards from Sangoma.

Sangoma produces a range of analogue and digital port cards. Some are completely dumb. Some offer hardware echo cancellation, to offload one of the most compute heavy tasks from the host CPU. This can provide a good balance for higher port density applications. Shown below are digital port cards supporting 1, 2, 4 and 8 T1/E1/J1 ports.

Shown below are analogue (FXO and FXS) port cards. The first supports only 4 ports, but a number of these cards can be stacked for higher desnity. The second card supports 8 ports.

You can find out more about this hardware at www.sangoma.com.

Cards from Digium.

Digium produces a range of analogue and digital port cards. Shown below are the TDM400P(a 4 port FXO/FXS card).The daughterboards determine which ports are FXO and which ar FXS); the TE110P (a single T1/E1/J1 port card); and the TE410P/TE405P (a quad port T1/E1/J1 card).

You can find out more about this hardware at www.digium.com.

Cards from Openvox.

Openvox is a fairly new Chinese entrant into the market for dumb telephony cards. Shown below are the B400P, a quad BRI port card; the D210P, a 2 port T1/E1/J1 card; the D410P, a 4 port T1/E1/J1 card; and the A1200P, a card offering a mix of up to 12 FXS and FXO ports.

You can find out more about this hardware from www.openvox.com.cn.

Cards from many sources.

There are many sources for cards using Intel modem interface devices, which may be used with Digium's Zaptel drivers. The quality of these varies considerably, which has given these cards a bad name. They are, however, quite cheap, and good implementations of the design can work well.