RTC client applications can encounter a Network Address Translator (NAT) or a firewall in the call path.

Firewalls and NATs are applications placed on the gateway to the Internet and protect devices on an internal network:

• A NAT maps one or more internal devices using internal IP addresses to a single external IP address.
  
• A firewall blocks certain kinds of incoming traffic.
  
• As of Windows CE, RTC 1.5 removed support for UPnP-based NATs. Instead, it enhanced its port manager APIs and also added support for symmetric UDP/TCP for better traversal of NATs.
  

 In This Section

NAT Address Mapping

Provides procedures to follow when an application is behind a NAT.

 See Also

Other Resources

Using the RTC Client API