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New Member

WAN Bandwidth Provisioning

Hello all,

I'm looking for a best practices threshold for upgrading the bandwidth on a circuit.

My guess is 70 percent. Above this the link performance starts do degrade.

Would you please give your thoughts about it?

Does somebody know any documentation related to it?

Regards,

Marcelo.

2 ACCEPTED SOLUTIONS

Accepted Solutions

Re: WAN Bandwidth Provisioning

Hello,

the 70% average is a good rule of thumb. What is meant by 70% is worth thinking about. Do you average busy hours or office hours or daily? The result can be quite different. I would recommend to take busy hours. The average can also be misleading. Assume - for simplicity - a 2 minute overload situation with lots of dropped packets and the 3 minutes idle. It will give you less than 50% usage in a 5 minute interval.

What you should do additionally to monitoring average load is to monitor the dropped packets on the link because of congestion. Once your router starts dropping a considerable amount of packets it would be about time to upgrade. In fact when you have the data at hand you can forsee, when the upgrade will be needed by looking at the extrapolation of the usage data.

You could also apply QoS to the link and make sure the critical applications get their required bandwidth even in an overload situation. Be aware that in this case you have to drop other less important traffic.

In any case the application response times and user input might also give a hint on when you would need to upgrade.

Hope this helps! Please rate all posts.

regards, Martin

Purple

Re: WAN Bandwidth Provisioning

Hi Marcelo,

I have been working with a number of a carriers over the past few years and the rule of thumb that they use for upgrading bandwidth is around 70-75%.

I'm not sure that you find any specific documentation regarding this. It is based on empirical evidence and operation experience.

Hope that helps - pls rate the post if it does.

Paresh

3 REPLIES

Re: WAN Bandwidth Provisioning

Hello,

the 70% average is a good rule of thumb. What is meant by 70% is worth thinking about. Do you average busy hours or office hours or daily? The result can be quite different. I would recommend to take busy hours. The average can also be misleading. Assume - for simplicity - a 2 minute overload situation with lots of dropped packets and the 3 minutes idle. It will give you less than 50% usage in a 5 minute interval.

What you should do additionally to monitoring average load is to monitor the dropped packets on the link because of congestion. Once your router starts dropping a considerable amount of packets it would be about time to upgrade. In fact when you have the data at hand you can forsee, when the upgrade will be needed by looking at the extrapolation of the usage data.

You could also apply QoS to the link and make sure the critical applications get their required bandwidth even in an overload situation. Be aware that in this case you have to drop other less important traffic.

In any case the application response times and user input might also give a hint on when you would need to upgrade.

Hope this helps! Please rate all posts.

regards, Martin

New Member

Re: WAN Bandwidth Provisioning

Martin, thank you for your response.

I liked the idea of coupling the dropped packet analysis with the utilization analysis.

The average I'm doing in based on business hours.

Do you know if there is any formula behind this 70% rule of thumb? Do you know where I can find documentation to support this recommedation?

Regards,

Marcelo.

Purple

Re: WAN Bandwidth Provisioning

Hi Marcelo,

I have been working with a number of a carriers over the past few years and the rule of thumb that they use for upgrading bandwidth is around 70-75%.

I'm not sure that you find any specific documentation regarding this. It is based on empirical evidence and operation experience.

Hope that helps - pls rate the post if it does.

Paresh

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