Digium Digital Cards

Digital Cards

Digital cards allow Asterisk to connect with T1, E1 and J1 digital lines (sometimes called “trunks”). Digital cards include one or more ports, each of which connects to an individual digital circuit. Trunks are often referred to as “spans”, thus a single port card is a “single span” device, while a four port card is a “quad span” device. Most digital cards connect using RJ-45 jacks (the same kind of jack as is commonly used for Ethernet connections). Connections between the card and a telephone company T1 line are connected using a “straight-through” cable (exactly like the cables that connect Ethernet ports). Connections between the card and a local PBX or other “CPE” device require a “cross-over” cable or a straight-through cable with a cross-over adapter.

Digital spans can be configured to carry telephone calls in several formats. (Note that the RJ-45 format is the current standard in North America but that physical form factors vary depending on region and telephone service provider.)

When selecting your PSTN interface device, be sure to find a model that supports hardware echo cancellation. Phone lines and even short-distance tie line connections to legacy gear frequently suffer from line and network echo. Hardware echo cancellation eliminates echo and provides a significantly better caller experience.
Asterisk connects with analog and digital telephony connections through either a gateway card that is installed in the host computer (the computer running Asterisk) or through an external gateway device. Internal gateway cards generally connect through the computer’s internal expansion bus. Cards are available in “PCI” and “PCI Express” (or PCIe) form factors. External gateways connect with Asterisk over the local area network (LAN) or the PC’s USB bus.

Internal gateway cards are the most common means of connecting Asterisk to the PSTN or to a legacy telecom system. Cards typically fall into the same categories as telephony connections: analog, ISDN-BRI, and T1/E1/J1 devices. (There are a few hybrid devices on the market that support both analog and ISDN-BRI.)

Digium Digital Card Family

The Digium Digital cards are designed based on the number of PRI spans (ports) that each card supports with 1, 2, and 4 span cards available.

TE122/TE121P – Single Span (1 T1/E1/J1 Port)
Used in conjunction with Asterisk®, the TE122 can be used to deliver a wide range of PBX and IVR services to the network or handset including Voicemail, Call Conferencing, Three-way Calling, and VoIP Gateways.

The TE122 is a single span, selectable T1 (24-channel), E1 (32-channel), or J1 (24-channel) card. The card utilizes Digium’s VoiceBus™ technology. VoiceBus technology allows the TE122 to use an industry standard bus-mastering PCI interface, as found in millions of PCs worldwide, to maximize system compatibility and eliminate system conflicts. Improving upon the prior TE120P which does not offer expansion capabilities, the TE122 may be combined with Digium’s VPMADT032 echo cancellation module to deliver 128ms of echo cancellation across 30 channels in E1 mode or 24 channels in T1 mode. Bundled with the VPMADT032, the product SKU is TE122B.

TE212P/TE220 – Dual Span (1 T1/E1/J1 Port)
The TE212P is a bundling of our leading TE210P product and our new VPMOCT064 Octasic DSP-based echo cancellation module. The TE212P is Digium’s and the industry’s first two-port digital card featuring hardware-based echo cancellation. The new module enables users to eliminate echo tails up to 128ms or 1024 taps across all 64 channels in E1 mode or 48 channels in T1/J1 modes. Further, this module takes advantage of the Octasic Voice Quality Enhancement to provide superior sound quality on all calls.

Digium has designed the TE212P to be fully compatible with existing software applications and it is fully integrated with the Asterisk Open Source PBX/IVR platform. Also, the open source driver supports an API interface for custom application development. With the combination of Digium Hardware and Asterisk software, numerous combinations of telephony configurations are possible. From the traditional PBX to VoIP Gateways, Digium solutions are paving the way for a new generation of worldwide communications.

TE410P/TE420 – Quad Span (1 T1/E1/J1 Port)
The TE410P supports E1, T1, and J1 environments and is selectable on a per-card or per-port basis. This feature enables signaling translation between E1, T1, J1 equipment and allows inexpensive T1 channel banks to connect with E1 circuits. Because the TE410P improves I/O speed by up to 10 times, the result is reduced CPU usage and increased card density per server.

Digium has designed the TE410P to be fully compatible with existing software applications and it is fully integrated with the Asterisk Open Source PBX/IVR platform. Also, the open source driver supports an API interface for custom application development. With the combination of Digium Hardware and Asterisk software, numerous combinations of telephony configurations are possible. From the traditional PBX to VoIP Gateways, Digium solutions are paving the way for a new generation of worldwide communications.