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.
A setting of 'Any' enables filtering for all traffic types, regardless of protocol. 'Other' is used for traffic that does not fall under any of the pre-defined protocols such as IGMP and RSVP.
When the field is set to IP it filters all traffic that is based on that protocol such as TCP, UDP. Port criteria cannot be set for rules that use IP because they relate specifically to either TCP or UDP. To set port information the protocol must be set to TCP or UDP.
Extra protocol-specific criteria are available when using IP, TCP or UDP:
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 | IP, TCP, UDP, ICMP, Any, Other |
| Default | TCP |
| XML file | rules.xml |
| XML name | <protocol> |
| XML values | ip, tcp, udp, icmp, any, other |