[nsp] GSR engine types?

[Rubens Kuhl Jr.]

Engine 2 cards like 3-port Gig-E are not wire-speed at all packet sizes. A
flood of small packets can't amount to 3 Gbps because of IFG (Inter Frame
Gap) limitations, but at near 1.5Mpps from each Gig-E interface, the 4 Mpps
engine runs out of steam.

The 4-port SFP card that comes with Engine 3 presents the same design
choice. This doesn't mean the 2 extra ports are useless; if some external
factor can limit the possible aggregate traffic, it's fine. Redundant
(active-standby, not active-active) connections usually presents such a
scenario.


Rubens


----- Original Message ----- 
From: "Tom (UnitedLayer)" <tom at unitedlayer.com>
To: "Rubens Kuhl Jr." <rubens at email.com>
Cc: <cisco-nsp at puck.nether.net>
Sent: Monday, January 12, 2004 8:39 PM
Subject: Re: [nsp] GSR engine types?


> On Sun, 11 Jan 2004, Rubens Kuhl Jr. wrote:
> > Too bad (if this document is complete) that so called "edge features"
still
> > aren't available on 3-port GigE cards (with Engine 3, it could support 2
> > GigE at wire speed), requiring one to buy a 10-port GigE card.
>
> So the 3 port GigE cards can't even do 3Gbps total?