What Does CBAC Inspect?
A number of applications use multiple ports to exchange data. You are surely familiar with the HTTP protocol, which uses port 80. The client transmits data from a randomly chosen higher-level port to the HTTP server's port 80. The HTTP server sources traffic from port 80 to whatever higher-level port the user initiated a connection from.
However, applications such as FTP and H.323 use more than one port. One port is used for a control channel, and another port is used for a data channel. To further complicate issues, some applications might redirect a user to an entirely different IP address for a data connection. An application might also redirect a user to an entirely different port to set up a control channel. Additionally, ...
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