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New Member

QoS bandwidth reserving

Hi,

I am playing with QoS and traffic policies and was hoping someone could set me straight on bandwidth usage. I know QoS reserves 25% bandwidth by default for internal process overhead, but is this actually needed for network traffic? Or just to keep the interface from being too busy?

Example:

Lab router 2514 is connected to the internet on Ethernet0 via 512 Kbps upstream cable modem. Do these 'internal processes' need the actual 128Kbps of the 512? Could I set the bandwidth of the interface to 682Kbps so it has 25% in addition to the 512Kbps of the internet connection as the interface is capable of more then 512?

Any info helps!

Thanks,

John

2 ACCEPTED SOLUTIONS

Accepted Solutions

Re: QoS bandwidth reserving

This is something you can decide yourself and it will not be the same for all systems.

For example, it makes quite some difference whether you are using a routing protocol or not.

You can adjust the default by specifying the usable bandwidth per interface using the following interface-command:

max-reserved-bandwidth 96

This example allocates 96% of the bandwith for user traffic.

regards,

Leo

Re: QoS bandwidth reserving

HI John, [Do RATE ALL HELPFUL POSTS]

In addition to Leo POST,

25% of Overall Bandwidth is reserved by QOS for Internal Route Processing Traffic like OSPF Updates / Eigrp Update / BGP Updates and other Routing Protocol Updates over WAN / LAN the QOS is implemented.

Do RATE ALL HELPFUL POSTS.

Best Regards,

Guru Prasad R

5 REPLIES

Re: QoS bandwidth reserving

This is something you can decide yourself and it will not be the same for all systems.

For example, it makes quite some difference whether you are using a routing protocol or not.

You can adjust the default by specifying the usable bandwidth per interface using the following interface-command:

max-reserved-bandwidth 96

This example allocates 96% of the bandwith for user traffic.

regards,

Leo

Re: QoS bandwidth reserving

HI John, [Do RATE ALL HELPFUL POSTS]

In addition to Leo POST,

25% of Overall Bandwidth is reserved by QOS for Internal Route Processing Traffic like OSPF Updates / Eigrp Update / BGP Updates and other Routing Protocol Updates over WAN / LAN the QOS is implemented.

Do RATE ALL HELPFUL POSTS.

Best Regards,

Guru Prasad R

New Member

Re: QoS bandwidth reserving

Thanks guys, that was exactly the information I was looking for. :)

Regards,

John

Re: QoS bandwidth reserving

guru bhai congrats on ur 500.

Re: QoS bandwidth reserving

One of other fundamental reasons for this reservation is to ensure that you do not completely starve bandwidth for the scavenging/best effort traffic when you configure your QoS policies.

Regards

Allan.

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