Ethan Banks Not writing about IT.

Tagenterprise qos

Enterprise QoS Part 09 – A consistent QoS strategy: end-to-end packet walk – congested vs. non-congested.

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If you’ve made it this far into the series, I have one simple point about QoS policy effectiveness that I want to bring home in this post before going through a couple of packet walks. The point is this. If an interface isn’t congested, your QoS policy dealing with congestion isn’t impacting traffic. Of course, rate limiters & marking policies will be effective whether your...

Enterprise QoS Part 08 – A consistent QoS strategy: shaping to match downstream bandwidth while still prioritizing.

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When dealing with the WAN, a common problem is that the actual available bandwidth of a circuit might different from the bandwidth of the physical circuit handoff. For example, a carrier might provide an enterprise with a gigabit Ethernet handoff, when in fact the connection is being throttled to 100Mbps downstream. A similar sort of problem appears when head-end bandwidth differs from remote...

Enterprise QoS Part 07 – A consistent QoS strategy: queueing collaboration applications at the WAN edge.

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As traffic flows across an enterprise’s network, there often comes a point where some part of the infrastructure is not owned by the enterprise. For example, enterprises with offices spread across several different cities usually rely on a telecommunications provider to connect the offices together. The telecom provider will layer the enterprise’s traffic on top of their own...

Enterprise QoS Part 06 – Using Cisco AutoQoS as a QoS baseline.

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Many large enterprises across the world use Cisco switching gear. As mentioned in previous parts of this series, implementing QoS across disparate devices, even within the Cisco ecosystem, can be frustrating as the syntax varies widely. In an attempt to reduce network operator frustration (as well as human error), Cisco introduced AutoQoS as a means to deploy a templated QoS policy on certain of...

Enterprise QoS Part 05 – A consistent QoS strategy: L2 & L3 traffic marking.

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A significant part of the challenge of delivering a QoS strategy to a network is in the execution. How, exactly, does one write a QoS policy that will accomplish business goals consistently across a diverse network infrastructure? There is no obvious answer to this question (and large books have been written on the topic), as the types of QoS tools to apply differ by network location and by the...

Enterprise QoS Part 04 – Can someone please explain all of these QoS terms?

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Like any IT discipline, QoS is awash in terminology & acronyms. I’m going to tackle the most common QoS terms here, and try to provide some context in my definitions. Ideally, you’ll know not just a definition of the term, but also how the term fits into the larger QoS ecosystem. ToS – ToS stands for “type of service.” The ToS value is stored in a byte of the IP...

Enterprise QoS Part 03 – Isn’t packet delivery at all costs the most important thing?

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When designing a QoS scheme to apply to an enterprise network, a common misconception is that delivery of all packets is the most important thing. The logic goes that an application is best served if all of the packets of a transaction are delivered, no matter what it takes to make that happen. Network engineers often go down the road of enlarging buffers as much as they can, in the hopes of...

Enterprise QoS Part 02 – Why do some applications require QoS, while others do not?

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With an introduction to QoS behind us, let’s start talking through some of the design concerns that drive QoS policy creation. What QoS problems do enterprises typically have? Network convergence is a trend that has stayed steady in enterprise (and service provider) networks for well over a decade now. The challenge with collaboration applications – voice & video especially...

Ethan Banks Not writing about IT.

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