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Bronze

Interface line rate and burst size

Hi everybody

I hope you guys are doing great.

 

An interface transmit data in the form of burst which is calculated as:

 

    Burst size ( bits)=Contracted access rate/32  , or contracted access rate /8  depending upon IOS.

 

My question is if we do not specify any rate say we have  fastethernet , what would be the burst size?

 

How can we see burst size being used by IOS?

 

thanks

 

Have a great weekend.

 

 

2 REPLIES
Cisco Employee

Hi, Can you please give some

Hi,

 

Can you please give some example to clear your question?

 

Regards,

Akash

Bronze

Thanks Akash for your

Thanks Akash for your response.

 

 

R1---f0/0-----------------f0/0  R2

 

R1 f0/0  has line rate of 100migbits/sec

When R1 has data to send to R2, it will not transmit the data in constant stream. R1 divides the whole one sec into number of Tc.

 

During each Tc, the data is transmitted at line rate i.e 100 Mig bits/sec. The amount of data transmitted  during TC is called burst . The question is when we do not define any shaper or policer

how is burst size determined ?

( if policer/shaper is being used Cisco IOS simply calculates the burst by using Burst= Tc *Police rate or shaper rate , it is IOS dependent , some use default  Tc =0125 sec, some Tc = 31 msec)

Please let me know if you need me to explain my question any further.

 

Much appreciated!!

 

have a great weekend

 

 

 

 

 

 

 

 

 

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