Product specifications

11N Wireless Broadband Router

RTSP, file transfer applications etc.

In order for these protocols to work through NAT or a

firewall, either the application has to know about an

address/port number combination that allows incoming

packets, or the NAT has to monitor the control traffic

and open up port mappings (firewall pinhole)

dynamically as required. Legitimate application data

can thus be passed through the security checks of the

firewall or NAT that would have otherwise restricted the

traffic for not meeting its limited filter criteria.

Usually allowing client applications to use dynamic

ephemeral TCP/ UDP ports to communicate with the

known ports used by the server applications, even

though a firewall-configuration may allow only a limited

number of known ports. In the absence of an ALG,