[pim] PIM yang model counter 64/32 bit

[Anish Peter <[e-mail]>]

Hello PIM group,
 We are doing pim yang model and came across this question of whether to
use a 64/32 bit counter for packet statistics. To the best of our knowledge
all the vendor models support 32bit counters.
 But given that we are having more scalable implementations, we had a
feeling that a 32bit counter may rollover too fast. To give some examples.

Right now now we have routers with more than 10K pim interfaces supported.
In such case even if we consider them to be p2p always, then it would mean
10K pim nbrs. In this case even if an aggressive hello timer of 10 seconds
is configured then it would transmit and receive about 60K pim hellos per
minute. This leads to about 86.4million hello per day. This way a 32bit counter
could roll over in less than 50 days. Half a decade back I had tested pim
for 4K interfaces with 1s hello interval. With this the same counter may
roll over in about 12 days time.

Similarly a pim null register and register stop too for a scale of 15K
group could easily roll over in less than 198 days.

The vendor counters are 32 for historic reasons and may not directly get
impacted by a stats model supporting 64bit.

 Please share your opinion.

Thanks,
pim yang model authors