The IAXy provides a single, fully featured FXS interface with an Ethernet back-end, speaking the Asterisk-native IAX protocol, at a highly competitive price. The IAXy is aimed at Voice Over Broadband and Internet Telephone Service Providers. The IAX protocol provides complete NAT transparency, enabling full operation behind NAT and PAT firewalls. This includes the ability to robustly transfer calls between endpoints, allowing on-net calls to be moved off of a service provider's network for better quality and lower cost.

The IAXy supports the following features:

Auto Upgrade
Caller ID
Call Waiting
Cancel Call Waiting (*70)
Caller ID on Call Waiting
Caller ID Disable, Enable (*67, *82)
Three-way Calling
Blind Transfer
Call Parking
Voice Mail Waiting Indicator (VMWI)
Mute Rx on-Hook
Pulse Dial
Call Hold