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5. Routed Mode and Proxy Configuration

5.1 Section [RoutedMode]

Call signaling messages may be passed in two ways. The first method is Direct Endpoint Call Signaling, in which case the call signaling messages are passed directly between the endpoints. The second method is Gatekeeper Routed Call Signaling. In this method, the call signaling messages are routed through the gatekeeper between the endpoints. The choice of which methods is used is made by the gatekeeper.

When Gatekeeper Routed call signaling is used, the gatekeeper may choose whether to route the H.245 control channel and logical channels.

Case I.

The gatekeeper doesn't route them. The H.245 control channel and logical channels are established directly between the endpoints.

Case II.

The H.245 control channel is routed between the endpoints through the gatekeeper, while the logical channels are established directly between the endpoints.

Case III.

The gatekeeper routes the H.245 control channel, as well as all logical channels, including RTP/RTCP for audio and video, and T.120 channel for data. In this case, no traffic is passed directly between the endpoints. This is usually called an H.323 Proxy, which can be regarded as an H.323-H.323 gateway.

This section defines the gatekeeper routed mode options (case I & II). The proxy feature is defined in the next section. All settings in this section are affected by reloading.

5.2 Section [Proxy]

The section defines the H.323 proxy features. It means the gatekeeper will route all the traffic between the calling and called endpoints, so there is no traffic between the two endpoints directly. Thus it is very useful if you have some endpoints using private IP behind an NAT box and some endpoints using public IP outside the box.

The gatekeeper can do proxy for logical channels of RTP/RTCP (audio and video) and T.120 (data). Logical channels opened by fast-connect procedures or H.245 tunneling are also supported.

Note to make proxy work, the gatekeeper must have direct connection to both networks of the caller and callee.


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