Product Documentation

How the Plug-in Selects an Appliance

Each plug-in is configured with a list of appliances that it can contact to request an accelerated connection.

The appliances each have a list of acceleration rules, which is a list of target addresses or ports to which the appliance can establish accelerated connections. The plug-in downloads these rules from the appliances and matches the destination address and port of each connection with each appliance’s rule set. If only one appliance offers to accelerate a given connection, selection is easy. If more than one appliance offers to accelerate the connection, the plug-in must choose one of the appliances.

The rules for appliance selection are as follows:

  • If all the appliances offering to accelerate the connection are redirector-mode appliances, the leftmost appliance in the plug-in’s appliance list is selected. (If the appliances were specified as DNS addresses, and the DNS record has multiple IP addresses, these too are scanned from left to right.)
  • If some of the appliances offering to accelerate the connection use redirector mode and some use transparent mode, the transparent-mode appliances are ignored and the selection is made from the redirector-mode appliances.
  • If all of the appliances offering to accelerate the connection use transparent mode, the plug-in does not select a specific appliance. It initiates the connection with WANOP Client Plug-in SYN options, and whichever candidate appliance attaches appropriate options to the returning SYN-ACK packet is used. This allows the appliance that is actually in line with the traffic to identify itself to the plug-in. The plug-in must have an open signaling connection with the responding appliance, however, or acceleration does not take place.
  • Some configuration information is considered to be global. This configuration information is taken from the leftmost appliance in the list for which a signaling connection can be opened.

How the Plug-in Selects an Appliance

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