Basic QoS Model
April 19th, 2010
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The basic QoS Model
Actions at the ingress interface include classifying traffic, policing, and marking: Read more…
Archive
Archive for the ‘QoS’ Category
QoS – DSCP Classification Guidelines (RFC 4594)
April 19th, 2010
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RFC 4594 describes some example and provides guidelines for DiffServ service classification which may be used as guidelines or as a basis for a QoS Classification Strategy: Read more…
QoS – Classification and Marking
April 19th, 2010
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The first element to a QoS policy is to classify/identify the traffic that is to be treated differently. Following classification, certain “marking tools” can set an attribute of a frame or packet to a specific value. Such marking (or remarking) establishes a trust boundary that scheduling tools later depend on. Read more…
QoS Markings: Layer 2 and 3 and IPv6
April 19th, 2010
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When data is sent through a network, it is able to be tagged with a “priority value”. When the data passes through a network device, the network device uses that priority value to determine how it should treat the packet. Data can be tagged with a priority value as described in the following article. Read more…
QoS Trust Boundaries
March 26th, 2010
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Cisco switches perform most Quality of Service (QoS) operations in hardware, while routers perform QoS functions in software. It is best practice to use the switch to perform deep packet classification and marking functionality on the switches. The router will need to re-classify the packet, but the classification can be on the DSCP marking rather than a transport layer port number. Read more…
QoS templates for Cisco Catalyst 3550
March 23rd, 2010
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Here are some QoS examples configured on a Cisco Catalyst 3550:
Read more…
WRR Queue – Parameters
January 26th, 2010
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The 3550 WRR (weighted round robin) scheduler algorithm utilises four configurable queues at each interface of the switch. Let’s consider just FastEthernet ports for simplicity in this post. For each queue, the following important parameters could be configured: Read more…
