Configuration for WAN interface

[ynyng]

I have a 500 / 500 Mbps connection from my service provider and I have a ASR1002. I am often utilizing the full 500Mbps download. What (if any) configuration should I input into my WAN interface to ensure optimal performance? I am assuming some sort of police or shape lines?

[Philip D'Ath]

Lucky you.

Before applying policing or shaping you really need a problem to solve.  Are you having any actual problems?

[ynyng]

I believe that I might be experiencing some packet loss and performance degradation at times of max use. A shaping policy might help with this?

[Joseph W. Doherty]

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Posting

It might, but only for egress.  Your physical hand-off is gig?  If so, a shaper would allow you to manage egress congestion before it hits your provider's bottleneck.  (BTW, most shapers don't account for L2 overhead, and if you shaper doesn't, you can shape about 15% "slower" to allow for average L2 overhead.)

If your physical hand-off is 500 Mbps, or if you use a shaper, using a FQ policy might help a bit.  Heavy flows don't impact the light flows, the same as they do with default global FIFO queue, and heavy flows get their packets dropped usually more so than light flows.

However, your OP noted it was downloads that max the link, and for those, practical congestion management is very difficult (except on the other side's egress) on regular Cisco routers.  You might compare the cost of a 3rd party traffic shaping appliance with obtaining more bandwidth.

[ynyng]

Thank you for your input. So basically you are stating that I can really only help egress traffic and ingress traffic can't be benefited?

I am in the process of purchasing 500Mbps from another provider to utilize and also serve and redundancy, but won't have it for a couple months. I was hoping to cost-effectively improve things in the interim...

[Joseph W. Doherty]

Disclaimer

The Author of this posting offers the information contained within this posting without consideration and with the reader's understanding that there's no implied or expressed suitability or fitness for any purpose. Information provided is for informational purposes only and should not be construed as rendering professional advice of any kind. Usage of this posting's information is solely at reader's own risk.

Liability Disclaimer

In no event shall Author be liable for any damages wha2tsoever (including, without limitation, damages for loss of use, data or profit) arising out of the use or inability to use the posting's information even if Author has been advised of the possibility of such damage.

Posting

Ingress - no benefit? - usually/practically, yes.

There can be some benefit - for example, if you police some traffic that you know hogs the bandwidth, at a very low rate, it often keeps such traffic from consuming all the ingress bandwidth.  The problem, though, an ingress policer is downstream of the traffic, so that traffic has a chance to congest the link before it's policed, and when there's ample bandwidth, when you wouldn't mind letting it have more, policers are usually static.

What you want is to manage the other side's egress, but most providers, especially ISPs, won't allow that, except, in my experience, with some MPLS providers that support some kind of QoS.  (Most provider's "solution" is to allow you to purchase more bandwidth from them.)