[j-nsp] bursit size for OC-192

Matthew Walster matthew at walster.org
Thu May 14 09:11:06 EDT 2009

2009/5/10 Andrew Jimmy <good1 at live.com>:
> Calculating burst size for low interfaces is very simple which is ten times
> the interface's MTU. For a high-speed interface, such as an OC-192, the
> recommended burst size is the transmit rate of the interface times 3-5
> milliseconds (AS per JNCIE book). Can someone write a real-time and
> practical example that how you calculate this 3-5 milliseconds thing
> exactly!

OC-192 is roughly 10Gbits per second.

That's 10Mbits per millisecond.

3x10Mbit per millisecond = 30Mbit in 3 milliseconds
5x10Mbit per millisecond = 50Mbit in 5 milliseconds

I don't know SONET MTUs, but Google says 4470 bytes, which is 35760 bits.

10 x interface MTU is 358kbits.

Does that answer your question?

Matthew Walster

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