QoS Models
There are three QoS models:
■ Best effort—Traffic is sent with no guarantees of bandwidth or priority.
■ Integrated Services (IntServ)—The QoS parameters are signaled
throughout the path and guaranteed for the length of the session.
■ Differentiated Services (DiffServ)—QoS parameters are applied to
traffic classes at each hop along the path.
Best Effort
Best-effort delivery is the default method—traffic is sent out in the order it
arrives with no differentiation between types of traffic and no guarantee of
delivery. Benefits of best effort include its scalability (the Internet is based
on best-effort delivery), and its ease of deployment. Drawbacks include the
fact that all traffic is given the same service level.