GE ML1200 Configuring QoS through the Command Line Interface, Qos, Set-weightweight=0-7

QUALITY OF SERVICE CHAPTER 14: QUALITY OF SERVICE

14.2 Configuring QoS through the Command Line Interface

14.2.1 Commands

The MultiLink ML1200 Managed Field Switch supports three types of QoS - Port based, Tag based and ToS based.

QoS is disabled by default on the switch. QoS needs to be enabled and configured.

The qos command enters the QoS configuration mode.

qos

The usage of the setqos command varies depending on the type of QOS. For example, for QOS type tag, the tag levels have to be set, and for QOS type ToS, the ToS levels have to be set. If the priority field is not set, it then defaults to low priority. ToS has 64 levels and the valid values are 0-63 and a tagged packet has 8 levels and the valid values are 0-7

setqos type=<porttagtosnone> port=<portlistrange> [priority=<highlow>] [tos=<0- 63listrange>]

[tag=<0-7listrange>]

Setting the type parameter to none will clear the QoS settings.

The set-weightcommand sets the port priority weight for All the ports. Once the weight is set, all the ports will be the same weight across the switch. The valid value for weight is 0-7

set-weightweight=<0-7>

A weight is a number calculated from the IP precedence setting for a packet. This weight is used in an algorithm to determine when the packet will be serviced

The show-portweightcommand displays the weight settings on a port.

show-portweight

As mentioned previously, the switch is capable of detecting higher-priority packets marked with precedence by the IP forwarder and can schedule them faster, providing superior response time for this traffic. The IP Precedence field has values between 0 (the default) and 7. As the precedence value increases, the algorithm allocates more bandwidth to that traffic to make sure that it is served more quickly when congestion occurs. The MultiLink ML1200 Managed Field Switch can assign a weight to each flow, which determines the transmit order for queued packets. In this scheme, lower weights (set on all ports) are provided more service. IP precedence serves as a divisor to this weighting factor. For instance, traffic with an IP Precedence field value of 7 gets a lower weight than traffic with an IP Precedence field value of 3, and thus has priority in the transmit order.

Once the port weight is set, the hardware will interpret the weight setting for all ports as outlined below (assuming the queues are sufficiently filled - if there are no packets, for example, in the high priority queue, packets are serviced on a first come first served - FCFS - basis from the low priority queue).

14–4 MULTILINK ML1200 MANAGED FIELD SWITCH – INSTRUCTION MANUAL