[j-nsp] M10 maximum throughput

[Stacy W. Smith]

On Dec 30, 2005, at 10:29 AM, Ihsan Junaidi Ibrahim wrote:

> Hi guys,
>
> Searched the archive from few immediate months but couldn't find an
> answer. As I understand it, M10 maximum throughput is 12.8 Gbps (6.4
> Gbps full-duplex). Say if I were to stick in 8 x GigE IQ PICs,  
> would the
> maximum bandwidth (8 Gbps) be counted against the full-duplex  
> ceiling or
> the 12.8 Gbps maximum throughput?

You should compare against the 6.4Gbps full-duplex throughput number.  
In addition, the M10's maximimum throughput can be more precisely  
described as 3.2Gbps full-duplex per FPC (horizontal row of PICs).  
Since there are two (built-in) FPCs that's a 6.4Gbps maximum  
throughput for the chassis.

A GE interface has a maximum throughput of 1 Gbps full-duplex. That  
is, it can be receiving 1Gbps of traffic at the same time that it is  
transmitting 1Gbps of traffic. 8 x GE interfaces would have a  
combined maximum throughput of 8Gbps full-duplex. Therefore, an M10  
with 8 GigE interfaces installed would be over-subscribed.

There's nothing wrong with oversubscribing the router as long as you  
understand that the combined throughput of of all PICs attached to a  
given FPC can not exceed 3.2Gbps full-duplex without experiencing  
packet loss. When you have 4 x GE interfaces installed on a given  
FPC, you could have each GE interface operating at an average of  
800Mbps with no packet lost.  Or, you could have 3 x GE interfaces  
operating at the full 1Gbps througput with no packet loss as long as  
the 4th GE interface on the FPC was operating at 200Mbps or less.

--Stacy