Re: DRR (Deficit Round Robin)

[Sandeep Bajaj <bajaj@cisco.com>]

"In reply to Gamze Tunali :"
> 
> Hi all,
> 
> I tried to use DRR and it always gave errors like (when I have 31 TCP
> connections between 2 nodes, there is only 1 hop):
> 
>   Collisions between 1 and 11 src addresses
>   Collisions between 257 and 267 src addresses

The problem is because the default number of DRR buckets is 10 and you have 31
sources. So the hash function modulo the number of buckets produces collisions. Please increase the number of DRR buckets appropriately using :

Queue/DRR set buckets_ <some sutiable number greater than 31>


Sandeep.

> I think the problem may be the hush function.. Why it uses this
> function:
>   ((i + (i >> 8) + ~(i>>4)) % ((2<<23)-1))+1;
> 
> If this function produces the same number for two different flowids than
> I guess collision error is given. Could somebody help me to understand
> what is going on?
> 
> Thanks
> 
> Gamze Tunali
> 
> 
>