Netgear GS418TPP User Manual - Page 435

ProSAFE 8-Port or 16-Port Gigabit Smart Managed Switch Model GS418TPP, GS510TLP, and GS510TPP DiffServ Traffic Classes With DiffServ, you define which traffic classes to track on an ingress interface. You can define simple BA classifiers (DSCP) and a wide variety of multifield (MF) classifiers: • Layer 2; Layers 3, 4 (IP only) • Protocol-based • Address-based You can combine these classifiers with logical AND or OR operations to build complex MF-classifiers (by specifying a class type of all or any, respectively). That is, within a single class, multiple match criteria are grouped together as an AND expression or a sequential OR expression, depending on the defined class type. Only classes of the same type can be nested; class nesting does not allow for the negation (exclude option) of the referenced class. To configure DiffServ, you must define service levels, namely the forwarding classes/PHBs identified by a given DSCP value, on the egress interface. You define these service levels by configuring BA classes for each. Creating Policies Use DiffServ policies to associate a collection of classes that you configure with one or more QoS policy statements. The result of this association is referred to as a policy. From a DiffServ perspective, two types of policies exist: • Traffic Conditioning Policy. A policy applied to a DiffServ traffic class • Service Provisioning Policy. A policy applied to a DiffServ service level You must manually configure the various statements and rules used in the traffic conditioning and service provisioning policies to achieve the desired Traffic Conditioning Specification (TCS) and the Service Level Specification (SLS) operation, respectively. Traffic Conditioning Policy Traffic conditioning pertains to actions performed on incoming traffic. Several distinct QoS actions are associated with traffic conditioning: • Dropping. Drop a packet upon arrival. This is useful for emulating access control list operation using DiffServ, especially when DiffServ and ACL cannot coexist on the same interface. • Marking IP DSCP or IP Precedence. Marking/re-marking the DiffServ code point in a packet with the DSCP value representing the service level associated with a particular DiffServ traffic class. Alternatively, the IP precedence value of the packet can be marked/re-marked. • Marking CoS (802.1p). Sets the 3-bit priority field in the first/only 802.1p header to a specified value when packets are transmitted for the traffic class. An 802.1p header is inserted if it does not already exist. This is useful for assigning a Layer 2 priority level based on a DiffServ forwarding class (such as the DSCP or IP precedence value) Configuration Examples 435