[nsp] load balancing over parallel DSL lines
Mark E. Mallett
mem at mv.mv.com
Thu Nov 20 18:29:59 EST 2003
On Thu, Nov 20, 2003 at 05:15:36PM -0600, Parrish, Ben wrote:
> Mark E. Mallett wrote:
> >> Load distribution: 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 (refcount 1)
> >I was (erroneously, I guess) thinking that this was telling me that
> >packets were only taking one of the paths. In the output above, the
> >"current path" note is only attached to one destination, and the
> >alterating 0s and 1s seemed to be confirming that only one
> >path was selected. Can anyone enlighten me on the true meaning?
> Mark, As I remember the hash used for CEF load-balancing has an output of 0
> to 7. Thus the queues are numbered the same. You have the two queses here
> that it is showing how it will distribute the load.
Somebody else pointed that out to me, and it was like throwing a light
switch in my brain. I had looked at the 0 1 0 1 sequence as a truth
table: false / true / false / true for a cyclic channel mapping. It
never even occured to me that this was a list of channel numbers taken
by a sequence of packets. Duh!
(I did attempt to find a detailed explanation of that output, but
to no avail.)
> (A packet for queue 0 and a packet then for queue 1, rinse, wash and
> repeat). There was an email that went out with in the last week or so that
> talked a little about this with regards to load-balancing on a Catalyst.
Guess I should have read the Catalyst-related threads :-)
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