Forwarding rate Mpps to Bpps

[jmprats]

Most switches express Forwarding rate in Mpps (Mega packets per second). I can see Cisco Nexus 93180YC-FX states it has 1.2 bpps (billion packets per second, I think).

How do you convert from Mpps to bpps? 1.2 bpps = 1200 Mpps?

Thanks

[Giuseppe Larosa]

Hello @jmprats ,

in digital transmission we use bps bit per seconds

1 Mbps = 10000000 bps

To conver from 1 million packets per second to bps we need to assign an average size to the packets and to take in account some ethernet L1 specifics like preamble and inter frame gap.

Preamble and IFG accounts for 20.1 bytes equivalent on wire.

the minimal size of an ethernet frame is 64 bytes.

To fill a 1 GE at line rate you need rouglhy 1,483 mpps of minimum size.

10^9   /   ( 64+20,1)*8

8 bits/byte

Hope to help

Giuseppe

[jmprats]

thank you, but I am not asking to convert Mpps (forwarding rate) to bps (Switch Capacity). I am asking to convert Mpps to Bpps.

As you can see on the Nexus 93108 datasheet Cisco express Forwarding rate in mpps i bpps

https://www.cisco.com/c/en/us/products/collateral/switches/nexus-9000-series-switches/datasheet-c78-742284.html

Thanks

[Giuseppe Larosa]

Hello @jmprats ,

ok I think 1 BPps  = 1000 MPPs

from the link you have provided :

>> The Cisco Nexus 93180YC-FX Switch (Figure 1) is a 1RU switch with latency of less than 1 microsecond that supports 3.6 Tbps of bandwidth and 1.2 bpps.

1.2 bpps =1,200 Mpps

Hope to help

Giuseppe

[Joseph W. Doherty · Accepted solution]

I believe (?) it's just by multiplying by 1,000.  (The reason I note "believe", the alternative might be to multiply by 1,024.  Even if it is, you would be close to the same value and it's a lot easier to just shift the decimal place by three.)