ProxySG Content Policy Language Guide
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Each of the protocol-specific proxy transactions has specific information that can be
tested—information that may not be available from or relevant to other protocols. HTTP Headers and
Instant Messaging buddy names are two examples of protocol-specific information.
Other key differentiators among the proxy transaction subtypes are the order in which information
becomes available and when specific actions must be taken, as dictated by the individual protocols.
Variation inherent in the individual protocols determines timing, or the sequence of evaluations that
occurs as the transaction is processed.
The following table summarizes the policy evaluation order for each of the protocol-specific proxy
transactions.
Table 2.1: When Policy is Evaluated
Transaction Type Policy is Evaluated....
Tunneled TCP transactions before the connection is established to the origin server.
HTTP proxy transactions Before the authentication challenge.
After the authentication challenge, but before the requested object is fetched.
Before making an upstream connection, if necessary.
After the object is fetched
FTP over HTTP transactions: Before the authentication challenge.
After the authentication challenge, but before the required FTP commands are
executed.
Before making an upstream connection, if necessary.
After the object is fetched.
Transparent FTP transactions Policy is examined before the requested object is fetched.
Real Media streaming
transactions
Before the authentication challenge.
After the authentication challenge, but before getting object information.
Before making an upstream connection, if necessary.
After the object information is available, but before streaming begins.
After streaming begins (this evaluation can be done multiple times, for example
after playback is paused and restarted).
Windows Media MMS
streaming transactions
Before the authentication challenge.
Before making an upstream connection, if necessary.
After the authentication challenge but before getting object information.
After the object information is available, but before streaming begins.
After streaming begins (this evaluation can be done multiple times, for example
after playback is paused and restarted).