[c-nsp] Information on Queuing commands and architectural differences

[Aaron Daubman]

Greetings,

I'm hoping somebody can provide some detailed Information on Queuing
commands and Cisco architectural differences.

Specifically, I'm wondering what the affect of the following command
is on different routers?
(e.g. Particle-based 7206VXR versus GSR, etc...)

Router(config-if)# hold-queue length {in | out}

Also, It would be great if there were pointers or info on how CEF or
other non-process-switching methods were/weren't affected by this
command and why.

Finally, some of the brief info I've found seems to suggest that the
above command relates only to interfaces using FIFO queuing.  What
affect would this command have if issued on an interface using CBWFQ
or DWRED and why?

I've found a handful of brief flowcharts without description that
begin to explain the above but have found no comprehensive source on
what this command does, what architectures it affects, and when it
is/isn't appropriate.

One particular statement I'd like explained is the following:

"""
You can adjust the input queue size with the command hold-queue size
input. Making the input queue significantly bigger is a perfectly
valid solution, especially on higher-end platforms that don't use the
input queue to switch packets.
"""

What do said higher-end platforms use to switch packets and what then
is the input queue used for?

Thanks as always,
     ~Aaron