The Alvis-2-PBX allows you to build a small stand-alone connectivity to the PRI networks and acts as a Transit Gateway or frontend Asterisk server.

2 T1/E1/J1 ports (PRI supported)
Full support for Asterisk versions 1.4/1.6
Codecs G.729/723 pre-included.
35 SIP/TDM SIP-SIP concurrent calls
PRI Native Bridging (0% CPU load)
Line Echo Canceller (Rev 2.x)
Green PC-less 3.5W only system!
3 year Warranty

One Texas Instruments TMS320DM6443 DaVinci dual core processor with 4752 DSP MIPS and 297 MHz ARM9 processing power.
Green PC-less technology, 3.5W power consumption only
256 MB DDR2 memory, 128 MB NAND shared flash memory, and 4GB SD-card memory
2 T1/E1 interfaces
Supports up to 35 simultaneous calls in any supported codec transcoding
Preloaded codecs support for G.723.1,G.729AB, G.726, AMR-NB, GSM-FR, etc… Other voice and video codecs like AMR-WB+, H.264, H.263, G.728 etc can be supported through third-party vendors
DSP/BIOS & Codec Engine Framework on DSP-core proxified by the XdmLink technology
10/100 Ethernet port for data transfer and remote access
Console Serial ports for debugging and application development
USB 2.0 port for an additional storage and adding interfaces like WiFi,GSM,WiMax
MicroSDHC card Class6 support for storing the linux and user's files like Voice Prompts or Voice Mail.
apt-get repository support for painless updates from http://packages.odints.com
Full support of the native Asterisk (r) 1.4, 1.6 and 1.8 (WiP)
Support of the FreePBX 2.7.x Web GUI
Included support of the T1E1 Analyzer Basic Odin's product to perform the seamless E1/T1 line setup

http://www.alvispbx.com/