Re: Dynamic Internet Bandwidth Allocation

[Jeff Kell <jeff-kell () UTC EDU>]

On 2/1/2012 9:00 AM, Miller,James R wrote:
> We are looking at combining our residence hall network with the campus network. The
> current structure of using a separate ISP for the residence halls seems a little more
> expensive. Still using separate IP structure, but we are looking at scheduling the
> majority of our bandwidth for the main campus during normal classroom hours and then
> dynamically allocating a large portion of the bandwidth for the residence halls to
> have available after hours.. Without too much study so far, it appears that our Exinda
> traffic shaping appliance may be capable of achieving this with virtual circuits and
> scheduling. Is there anyone out there doing this currently, and if so would you mind
> sharing what equipment or software you are using to do this?

We were a former Packeteer customer, and did this by choosing a fixed bandwidth slice
for Resnet traffic, and adjusting the size based on day-of-week / time-of-day.  In later
software this could be allocated as a percentage of the pipe (less traumatic when you
added additional bandwidth).  The problem here was the pipe was a fixed size, and could
not use any remaining bandwidth that the campus might not be using.

We are now using Procera.  There is a similar scheme of traffic allocation (class days,
evenings, and after-hours/weekend) in increasing increments.  However, during the class
days, if the entire bandwidth is utilized (which it generally is), it is set to "borrow"
first from the evening slice, and second from the after-hours slice.  However, the
relative "priority" classification of the traffic is dropped by one for each step down
the "borrowing" ladder.  This keeps campus traffic (for the same priority classes)
ranked above the dorm traffic.  This makes better utilization of the overall bandwidth
while maintaining priority for your campus traffic.

In any case, if you restrict Resnet (or any other) traffic to a small pipe, you will
have to address the "bandwidth hogs" so that they do not monopolize the available
bandwidth.  With Packeteer we tried using dynamic partitions by IP address.  With
Procera we use Volume Based Shaping, which kicks in bandwidth throttling depending on
the volume of data consumed in a given quota interval.  Other devices like a
NetEqualizer do this type of balancing by default.

Jeff