[j-nsp] MX vs. M

[Richard A Steenbergen]

On Sat, Nov 22, 2008 at 02:04:19PM +0800, Mark Tinka wrote:
> On Saturday 22 November 2008 07:51:49 Jose Sanchez wrote:
> 
> > Here is a recent announcement in the Juniper DPC
> > datasheet: MX-FPC
> 
> I've asked our SE if they can get the MX-series PLM to 
> consider providing support for PE-type PIC's (those used on 
> the M7i and M10i).
> 
> If a network is using OC-12/STM-4 and OC-48/STM-16 on the 
> M7i/M10i, and want to migrate to an MX-based core, it'd be 
> nice to know these line cards would be supported.

There is no OC-48 on the M7i/M10i (unless you're taking one of the old
I-1OC48-SON cards and pulling it off the FPC, but that takes up 4 PIC
slots and wouldn't work in another platform). Even the 1-port OC-48 card
is a type-2 PIC which would be supported under the type-2 MX FPC (*).

But think of it this way... The density on the type-2 MX FPC is pretty
terrible (taking up 2 MX slots for 2 type-2 PICs, or trading 80Gbps of
bw for 5Gbps), and the price is nearly that of a 4x10GE DPC. You've
really gotta be pretty darn desperate for a SONET PIC to go to that much
trouble and expense, and I personally don't think there are any type-1
PICs which are valuable enough to make that a viable product.

This is the same argument I've made against the T640 FPC1, the price of
the FPC far outweighs the price of buying a more sensible platform like
an M7i and the uplink and downlink GE ports for it, not to mention
saving you on valuable lost slot real estate. The type-2 FPC makes sense
if you consider your alternatives for supporting a single OC48 PIC (M120
or T320 being the smallest, M160/M320/T being your only other options),
but I personally can't think of a reason for a type-1 FPC for MX.

(*) Does anyone from Juniper know if the old PB-1OC48-SON-SMSR cards 
from M160 is supported, or only the new PB-1OC48-SON-SFP as mentioned in 
the MX-FPC docs. I know the old fixed optics cards are EoL, but it's not 
clear if they are going to be unsupported in the MX-FPC or simply 
aren't mentioned because they are EoL.

-- 
Richard A Steenbergen <ras at e-gerbil.net>       http://www.e-gerbil.net/ras
GPG Key ID: 0xF8B12CBC (7535 7F59 8204 ED1F CC1C 53AF 4C41 5ECA F8B1 2CBC)