Using the Linksys SPA400 with Asterisk

Features:

Connects 4 Analog PSTN Lines to your LVS9000
4 RJ-11 FXO Ports
Integrated Voicemail Application Server
Enables SPA9000 IP Phone Clients to Leave and Playback Voicemail
USB 1.1 Host Interface for the Voicemail Module and Application
Configure up to 32 Voicemail Accounts
Caller ID Detection
Hunt Grouping of FXO Ports
Advanced Inbound and Outbound Call Routing
Independent Configurable Dial Plans to Utilize Multiple Service Providers

http://hiasterisk.blog.com/2013/05/04/configure-linksys-spa400-with-asterisk-elastix-voip-server/

http://forum.voxilla.com/threads/using-the-linksys-spa400-with-asterisk.13530/