[c-nsp] Which would be better?

[Jon Lewis]

On Sun, 21 Nov 2004, Tuc wrote:

> 	Talking to another tech, there are performance issues with the
> ethernets previously mentioned.... He has available (potentially) either:
>
> 	I'll get a pair of PA-FE-TX  in a vip2-50 w/ 128mb ram
> 		or
> 	PA-2FE-TX-ISL in the vip2-50 (Cheaper)

If you go with the PA-2FE-TX-ISL, there will be more performance issues.
Cisco has a paper burried somewhere deep in cio.cisco.com that shows that
the PA-2FE-TX-ISL cannot do line rate on both ports simultaneously, and
it'll be a real drag on the VIP's CPU if you try to push signifigant
traffic through either port on a PA-2FE-TX-ISL.  The same goes for putting
one in a 7200...only worse, it drags the whole router down.

If you can't afford the PA-2FE (the one that's still a few $k used IIRC),
go with single port PA-FE's and enough VIPs (VIP2-50 or better) to
accomodate them.  There's a reason PA-2FE-TX-ISL's are so cheap on the
used market.

----------------------------------------------------------------------
 Jon Lewis                   |  I route
 Senior Network Engineer     |  therefore you are
 Atlantic Net                |
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