[j-nsp] MX vs. M - Update!

[Mark Tinka]

On Sunday 23 November 2008 07:48:48 Richard A Steenbergen 
wrote:

> 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.

The consistent problem of trying to turn an Ethernet box 
into an SDH/SONET router as well.

We saw what happened when Cisco tried to do this for their 
6500 and 7600 platforms, with the FlexWAN carrier cards, 
and now the SIP carrier cards.

The fact of the matter is that with more carriers (local, 
regional and international) opening up support for Ethernet 
LAN/WAN PHY for IPLC's, it sometimes makes sense to look at 
a box like the MX-series for the core, especially since it 
has the non-R-Q DPC's that make upgrades to 10Gbps cheaper 
than what you'd get on other routing platforms.

If anything, the MX-FPC would be a temporary and short-term 
solution if Ethernet were not possible, and service 
providers had to stick SDH/SONET somewhere into the core 
(if it's cheaper than buying an M7i/M10i with a 
corresponding PIC, that is). The only issue is that given 
that the MX-FPC takes up two whole slots, there's quite a 
trade-off in bandwidth without a corresponding reduction in 
cost (for the MX-FPC).

What would probably have made more sense is a DPC-FPC combo 
that takes up only a single slot, so that Juniper could 
develop single-width (if I can call them that) PIC's, 
sacrificing only half the bandwidth to support SDH/SONET, 
based on today's MX-series switch fabric.

Yes, it means developing a whole new range of PIC's for a 
box that might not be a success in the SDH/SONET space, but 
it might be more palatable if pitched against using 
existing PIC's over 2 slots and losing nearly 80Gbps of 
bandwidth, or buying new PIC's for one slot and losing only 
half that.

Of course, when the switch fabric does get upgraded to 
80Gbps/slot, 100Gbps/slot, or more, this DPC-FPC combo 
would just as well become more difficult to justify, unless 
the PIC's can be made a lot smaller so you can fit more on 
one DPC-FPC; but that's not something I'm qualified to 
posit about.

Mark.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 835 bytes
Desc: This is a digitally signed message part.
URL: <https://puck.nether.net/pipermail/juniper-nsp/attachments/20081123/b12a8dba/attachment.bin>