[c-nsp] 6509 weird pps value

[Saku Ytti]

On 1 June 2016 at 19:30, Ben Hammadi, Kayssar (Nokia - TN/Tunis)
<kayssar.ben_hammadi at nokia.com> wrote:

Hey,

>  As per my knowledge , when we mix DFC and CFC module , Sup capacity in term of PPS will fall to 15MPPS  , but I see some weird value such as 214 Billion pps and 30 billion pps in the output below , what does this mean ?

If linecard has DFC, lookup is done on the DFC and packet is sent over
fabric to destination(s), i.e. it is not using lookup capacity of SUP.
If linecard does not have DFC, then packet headers are sent over DBUS
to SUP for lookup and lookup result is sent over RBUS (where each
linecard copies it), and linecards not needing the packet purge it.
It does not matter if you mix and match, behaviour is dictated by
ingress linecard.

Now the 15Mpps is not really exact number. The SUP lookup performance
is limited by DBUS capacity. We can never congest the lookup engine
itself, we simply don't have enough capacity towards it. DBUS is
62.5MHz and transfers 32B per cycle. IPv4 lookup uses 64B headers,
IPv6 and MPLS lookup uses 96B headers. Consequently IPv4 is
62.5MHz/2cycles => 31.25Mpps, MPLS and IPv6 are 62.5MHz/3cycles =>
20.83Mpps.
If lookup also requires recirculation, for every recirculation needed
performance is halved.

30Bpps, 214Bpps are bugs, those values are not possible.

>     Forwarding engine load:
>                      Module       pps   peak-pps                     peak-time
>                      2         198313   181027384  21:56:54 GMT+1 Fri Apr 15 2016
>                      3         379682   4092767857  08:55:20 GMT+1 Wed Dec 17 2014
>                      4              0   149982456  14:10:33 GMT+1 Sun Jan 18 2015
>                      5        1135379   21448701149  19:35:24 GMT+1 Sun Aug 30 2015
>                      6          16254     109212  16:35:01 GMT+1 Wed May 25 2016
>                      7         459665   532775771  22:38:55 GMT+1 Wed Jan 7 2015
>                      8         207789   21962852  08:28:16 GMT+1 Sun Jan 18 2015
>                      9         384508   3050062992  17:49:49 GMT+1 Mon Mar 23 2015




-- 
  ++ytti