A class is a group of users, defined by IP address. All users within the group receive the same quality of bandwidth service, as defined by the shaping policy. The Bandwidth module comes with an All traffic class predefined. This is a “catch-all” class for traffic originating from an IP address not assigned to an existing class. The Default shaping policy is applied. Changes to the class Name are reflected on the Interfaces page automatically. Deleted classes are automatically reflected on the Interfaces page.
Not all applications are classified perfectly. This applies to protocols designed to avoid detection, such as BitTorrent, or some peer-to-peer protocols. In some cases, such traffic might be classified as Unknown.
Typically, such protocols use more bandwidth. To guarantee that the protocols are restricted, you can create a policy, which restricts the amount of available bandwidth for unknown traffic and add exceptions for allowed protocols. However, many connections are classified as Unknown initially until several packets are sent. A policy that blocks those protocols, rather than restricts them, might be more practical.
Note: Encrypted, secure packets might be classified as SSL traffic where another application group doesn't exist. However, there are some protocols that were not originally encrypted, but might have been upgraded using SSL, so might be classified as such now. Also, there are some protocols, which use SSL as part of their protocol specification, in which case, these might be classified correctly.
See our knowledge base article, Layer 7 Application Classifications.