[nsp] Sup 720

[Lincoln Dale]

Hi,

since noone has yet responded, i'll take a stab at some of your questions..

At 09:53 AM 9/04/2003 +0300, Pekka Savola wrote:
> > > http://newsroom.cisco.com/dlls/prod_033103.html
> > > A new 6500 sup? with builtin SFM?
>
>I wonder if folks have had any new information on this yet?
>Looking at the slideware, a few questions spring to mind:
>
>- the performance improvement is only obtained when using new linecards,
>it seems with dCEF/aCEF -- otherwise it's back to 32(?) Mpps.

the Sup720 supports all previous architectures of switching through 
previous-generation linecards.

that is:
  - if you had a linecard that was "fabric enabled" but used "centralized
    forwarding", the Sup720 crossbar will provide that linecard with the
    same fabric interface that the previous SFM provided.
    i.e. a 256gbit/s crossbar.
    in the newer taxonomy, this is referred as a "CEF256" linecard.

  - if you had a 'classic' linecard -- that is, a linecard that was not "fabric
    enabled" but utilized the "centralized forwarding", traffic to/from that
    linecard will continue to use the 32gbit/s bus backplane.

the PPS that a given linecard is capable of is really a function of whether 
that linecard utilizes centralized-forwarding or local-forwarding 
(DFC-enabled or not) - with the Sup720 providing a higher 
centralized-forwarding rate than the previous Sup2 and newer features that 
previous linecards couldn't [previously] use.

>- it is not clear whether new interface modules will support both
>"dCEF720" and "aCEF720".

in most cases, yes.
the linecard datasheet (and configurator) it will state if they can.

if 'yes', then an "aCEF720" module can be upgraded to a "dCEF720" module 
using a WS-F6700-DFC3A

>- it is not clear whether you can enable dCEF on a system which has other
>than dCEF720 or dCEF256 linecards (and performance tradeoffs of that)

if you had a previous-generation linecard with a DFC, that will need to be 
upgraded to a DFC3 (WS-F6700-DFC3A) or depopulate the original DFC to use 
the Sup720 with centralized forwarding.

>- it is not clear whether you can enable aCEF on a system which has other
>than aCEF720 linecards (and perfomance tradeoffs of that)

yes, you can.
aCEF720 is local-switching on the linecard based on initial input from the 
centralized forwarding engine.
the whitepaper at http://newsroom.cisco.com/dlls/Sup_720_DS.pdf covers this 
on page 15.

>- IPv6-enabled software for 7600 was slideware (not released for the
>public) for about 9 months or more.  I wonder about support for sup720 and
>the features.

the forwarding ASICs in the Sup720 support IPv6 natively.

the whitepaper at http://newsroom.cisco.com/dlls/Sup_720_DS.pdf states "up 
to 200 million PPS hardware-based IPv6 in distributed forwarding 
mode".  you can do the math to work that out per-linecard.

the same whitepaper says that IPv6 will be enabled with IOS 12.2(14)SY and 
later.

>- exact IPv6 performance was briefly mentioned only once ("up to 200 Mpps
>or so"), it would be nice to get better figures.

going entirely from memory, the PFC3 ASIC complex can switch IPv6 at 25M 
packets-per-second.
each "dCEF720" modules (DFC3) contains the same ASIC complex that make up 
the PFC3 but on each linecard.

on a 6509 chassis, that equates to 8 slots of "dCEF720" modules switching 
at 25M PPS each (distributed; 8 x 25M PPS = 200M PPS).
i'm not sure why the math wasn't done with a 6513 chassis; perhaps just 
recognition that there's a ton of 6509s out there.

>- the price differences with previous linecards and new linecards (are
>they expensive or extravagantly expensive)

a loaded question. :-)
you'll need to talk to your account-manager!

having said that, the 2-port and 4-port 10GE linecards are a significant 
price reduction on the previous 1-port 10GE linecard.
likewise, the cost of a Sup720 is quite a bit less than that of previously 
purchasing a Sup2+(SFM|SFM2).

to my mind, it being a high-end product, it'll never be "cheap" per-se -- 
but look at the functionaliy thats now there - even the original linecards 
that are now around 4 years old can now do IPv6, v4-to-v6-tunneling, 
v6-to-v4-tunneling, MPLS, egress rate-limiting, fine-grained rate-limiting 
and all the other 'new' Sup720 features.  as a platform, thats pretty good 
investment protection!


cheers,

lincoln.