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Differentiated Services Code Point (DSCP) is used to specify the traffic priorities over the IP header of the frame. Differentiated Services is a multiple service model that can satisfy differing QoS requirements. Here, the network tries to deliver a particular kind of service based on the QoS specified by each packet. This specification can occur in different ways, for example, using the 6-bit DSCP setting in IP packets or source and destination addresses. The network uses the QoS specification to classify, mark, shape, and police traffic, and to perform intelligent queuing.
Also it is used for several mission-critical applications and for providing end-to-end QoS. Typically, Differentiated Services is appropriate for aggregate flows because it performs a relatively coarse level of traffic classification. Use the DSCP so that router can use the priority bits in the Type of Service (ToS) octet to prioritize traffic over QoS in layer 3. Use the DSCP to Queue page to queue traffic based on the DSCP value in the incoming packet. Based on the this value and the associated priority value the packet travels through the LAN switch.
This article explains the mapping of DSCP to Queue traffic in SRP520 Series.
• SRP520 Series
Mapping of DSCP to Queue Traffic
Step 1. Use the Services Ready Platform Configuration Utility to choose Network Setup > QoS > DSCP To Queue. The DSCP To Queue page opens.
Step 2. Change the priority settings for each IP DiffServ value as necessary and priority level from the drop-down list. The priority defines the traffic forwarding queue to which traffic with the given DSCP is mapped.
• DiffServ — Differentiated Services(DiffServ) are hexadecimal values in which traffic is treated by intermediate systems with relative priorities based on the type of services (ToS) field. It increases the number of definable priority levels by reallocating bits of an IP packet for priority marking.
• Priority — This field is used to specify the level of bandwidth requirements. The available priorities are as follows:
• Strict — Sets the bandwidth requirements for strict priority traffic. This option has the highest priority of all.
• High — Sets the bandwidth requirements for high priority traffic.
• Medium — Sets the bandwidth requirements for medium priority traffic.
• Normal — Sets the bandwidth requirements for normal priority traffic. By default, most of the ports are set to normal.
• Low — Sets the bandwidth requirements for low priority traffic. This option has the lowest priority.
Step 3. Click Submit to save the settings.