The Eyeball AnyFirewall™ Engine (AFE) is a software library that enables seamless traversal of NATs, firewalls and web proxies for VoIP and other communications applications and devices. It offers the following features:

Figure 1 shows the internals of Eyeball AnyFirewall Engine (AFE), and how it can be used in different applications.

Figure 1: Internals of AnyFirewall Engine, and 3 applications using it.

AFE works best with Eyeball AnyFirewall Server – a carrier-grade STUN and TURN server. Figure 2 illustrates two applications using Eyeball AnyFirewall Server to establish communications between them. The main purpose of Eyeball AnyFirewall Server is to help AFE in NAT/firewall discovery, and if required, relaying of signaling/media data. Although AFE works with any STUN-TURN server for standard STUN/TURN features, it is dependent on Eyeball AnyFirewall Server for traversing web-proxies using http-tunneling (due to lack of standardization for http-tunneling).

Figure 2: Eyeball AnyFirewall Engine works best with Eyeball AnyFirewall Server. The server helps AFE in NAT/firewall detection and data relaying.

This document describes functionality and usage of Eyeball AnyFirewall Engine for the supported OS platforms.