EXOS Rate Limiting and Rate Shaping

[Anonymous]

Converting QoS EOS understanding to EXOS, which is causing me a little confusion.....

My understanding between the difference of rate limiting and rate shaping is the former simply sets a red line, so anything above it can be dropped. Whereas the later is more smooth and buffered.

Could someone please give me an example configuration of the two in EXOS to help me understand this?

Also a practical use for each. So for example, I might use traffic shaping for voice or video, and rate limiting for say backup traffic. The reason is the voice and video wouldn't be so tolerant to packet drops then say backup traffic, so I would want to buffer voice where I can rather than drop - would that be an accurate analogy?

Many thanks in advance.

[Keith9]

I know that this is an older topic but it comes up frequently in my search engine results when I am researching this very topic to find out the best way to transition from Cisco to XOS equipment for our routing to our core HQ.

You forgot another point:
Practical use of rate limiting:
For service providers to artificially limit bandwidth on an otherwise fully capable port / fiber to customer in order to create a revenue stream by offering tiered speed packages. Its all about the money.

While most of us on this forum probably are not service providers, nor are we fueled by the same level of monetization as they are... we all might subscribe to a provider that recommends or requires traffic shaping on the egress port connected to their service. A good explanation from one provider is here at CentruyLink's page: https://www.centurylink.com/business/help/network/overview-of-traffic-shaping.html

I know most Telco's offering a Metro-Ethernet service will suggest or require traffic shaping for best performance, however I have not heard of the same requirements from the Cable operators also offering fiber optic Metro-Ethernet service. The Cable operators usually hand off from a Ciena switch, so perhaps they handle it right there in their equipment. Many of the Telco's provide a NID and allow you the subscriber to self terminate to it. If that's the case, the NID is simply nothing more than a simple media converter. Some Telco's may provide a managed router, and I would wonder in that case if they have remote access to properly setup the traffic shaping according to your billable rate.

Thanks!

[Anonymous]

Thanks both for posting as this has helped a lot. Much appreciated.

Might think of some more questions later on but I have one to ask now....

My plan moving forward might be to use WRR, so my thoughts are that I would then have no use for rate limiting since I can simply order the weights accordingly in sharing bandwidth.

The intention would be to use Strict Priority on say QP8 (Control traffic) and QP7 (reserved for stacking) and weight any other queues used, including QP1

Would that be a good practice?

Many thanks.

[Anonymous]

Great. Thanks Erik.

[Erik_Auerswald]

The idea is good, but I am not sure if mixed queuing strategies can be implemented in EXOS. WRR should should be fine, since it prevents starving of lower priority queues.