Patton electronic 2800 Specifying the handling of traffic-classes, Defining fair queuing weight

OnSite 2800 Series User Manual 8 • Link scheduler configuration

At a some point the source traffic-class default must be listed. This class must be present, because it defines how packets, which do not belong to any of the traffic-classes listed in the profile are to be handled. When all listed “traffic-classes” have “priority” the handling of the remaining traffic is implicitly defined and the “default” sec- tion can be omitted. Similarly if no scheduling is used i.e. the link scheduler is used for packet marking only (e.g. setting the TOS byte) the “default” section can also be omitted.

The table below shows the basic syntax of the service-policy profile structure:

Mode: Configure

Step	Command	Purpose
1	node(cfg)# profile service-policy name	Creates a new service policy profile
		named name
2	node(pf-srvpl)[name]#rate-limit value	Limits global interface rate to value in
		kbps. Be aware, that the actual rate-
		limit on a given interface has to be
		defined for reliable operation.
3	node(pf-srvpl)[name]#mode {shaper wfq}	Sets the arbitration scheme to mode
		shaper or weighted fair queuing (wfq).
		If not specified wfq is default.
4	node(pf-srvpl)[name]#source {traffic-class policy}	Enters source configuration mode for a
	src-name	traffic-class or a hierarchical lower
		level service-policy profile named src-
		name.
5	node (src)[src-name]…	At this point the necessary commands
		used to specify the handling of the traf-
		fic-class(es) have to be entered.
6	node (src)[src-name]exit	Leaves the source configuration mode
		(optional)
7	node(pf-srvpl)[name]#…	Repeat steps 4 to 6 for all necessary
		source classes or lower level service
		policy profiles.
8	node(pf-srvpl)[name]#exit	Leaves the service-policy profile mode

Specifying the handling of traffic-classes

Several commands are available to specify what happens to a packet of a specific traffic-class.

Defining fair queuing weight

The command share is used with wfq link arbitration to assign the weight to the selected traffic-class. When defining a number of source classes, the values are relative to each other. It is recommended to split 100— which can be read as 100%—among all available source classes, e.g. with 20, 30 and 50 as value for the respec- tive share commands, which represent 20%, 30% and 50%.

Link scheduler configuration task list 104