Firewalls and NATs (Windows CE 5.0)
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.
The RTC Client API maps IP addresses and ports of Universal Plug and Play (UPnP)-enabled NATs. If the client is located behind a UPnP-enabled NAT, the RTC Client API determines the relevant IP address and port mapping on the NAT or firewall to allow for audio streaming and SIP traffic.
If the client is located behind a NAT that is not UPnP-enabled, the RTC Client API cannot determine the relevant IP address and port mapping. In this situation, the client application must determine these mappings and supply them to the RTC Client API.
In This Section
- Traversal of UPnP-Enabled NATs
Provides information about the behavior of the RTC Client API when an application is behind a UPnP-enabled NAT. - NAT Address Mapping
Provides procedures to follow when an application is behind a non-UPnP-enabled NAT.
See Also
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