[f-nsp] Looking for throughput infos

Richard A Steenbergen ras at e-gerbil.net
Sat Sep 16 16:42:35 EDT 2006


On Sat, Sep 16, 2006 at 07:22:55PM +0200, Simon Leinen wrote:
> Richard A Steenbergen writes:
> > You think so? Sup32 is little more than a rebadged sup2/msfc2 (sorry
> > thats msfc2*a*, its completely different after you add that "a")
> > with some optional onboard interfaces (aka the only way you'll ever
> > do 10GE on the thing). In exchange, it gets a hearty crippling (at
> > least sup2 you can add a fabric card). Other than supporting newer
> > IOS going forward (aka Cisco forcing people to pay again), Sup32 has
> > very little going for it.
> 
> What it does have is a PFC3B.  This means hardware forwarding for IPv6
> and MPLS, including encapsulation and decapsulation for IPv6 in IPv4
> and Ethernet in MPLS (EoMPLS), and hardware rate-limiting of packets
> punted to the MSFC (CoPP).

Yes but mostly unimportant for Sup32 users, since if you really need those 
features you probably really want a SUP720/MSFC3 (or soon MSFC4) to 
actually use them. MSFC2 is so underpowered (with the existing IOS 
scheduler) it isn't even funny. If you've got a few BGP sessions 
configured, you can easily start it into a loop from which it will not 
recover without manual intervention just by changing a route-map, doing a 
few soft clears, and writing mem in quick succession. Even with 180 sec 
holdtimes, the msfc will be so bogged down it will not be able to respond 
to keepalives and drop a bgp session, which will cause more cpu churn as 
it tried to elect and install new best paths, which will cause more bgp 
sessions to drop, until you manually shut them down and bring them up one 
by one, slowly.

Oh and don't forget, you'll be suffering complete tcam exhaustion in 1-2 
years, since you can't upgrade that PFC3B to a 3BXL on a Sup32. They're 
already suffering from the problem of current IOS coming with default cam 
partitioning which is too small for the current routing table. Technically 
speaking, FPC2 will survive longer here too, since it has the full 256k 
entries available for IPv4 vs only 239k after max tuning on the Sup32 
(since some are reserved for V6/MPLS even if you don't need them).

The only place it makes any kind of sense at all is if you know for a fact 
you will never need more than the 2 onboard 10GE ports of the SUP32-10GE 
option, and you're fine with all fabric cards to feed them (since there is 
no other way to put 10GE on classic bus boxes). If stackables with 24/48 
port gig and 2-port 10GE could take full tables, you'd eliminate half of 
the Sup32 market right off the bat.

But at any rate, this is a Foundry list so I'll stop now. :) Bottom line, 
even an old Foundry box offers stiff competition to a Sup32, and thats 
saying something.

-- 
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)



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