Each stream has an associated protocol that determines the method used to transmit the traffic. Protocols define strict conventions for how the data is packaged and the systems used to ensure faultless delivery.
Rules allow you to specify which protocol is to be processed. They also provide criteria related to the protocol such as source and destination address, ports and acknowledgement prioritization as used with TCP.
The protocol can be set by selecting the appropriate entry from the rule classification window. All traffic streams that use the selected protocol at layer 3 will be filtered by the rule.
Additional criteria are available for TCP including:
The protocol field is accessible through the properties window for the rule under the Classify tab:

| Name | Value |
|---|---|
| Property Name | Protocol |
| Category | Rule Classification |
| Values | TCP |
| Default | TCP |
| XML file | rules.xml |
| XML name | <protocol> |
| XML values | tcp |