At the University of Indianapolis, we have the Packetshaper placed between out on site router and our WAN router, all internet traffic whether
in-bound or out-bound passes through it. We have not noticed any performance hits thus far. The positive impact it has had on bandwidth usage has been
With peer-to-peer traffic set to low priority, and other traffic set to high priority, when high priority traffic dies down, the low priority traffic
gets to use more of the available bandwidth. If high priority traffic levels increase, p-2-p traffic is throttled back.
Director Network and Systems
Jeff Ogden wrote:
> This discussion thread on "Network Performance or Bandwidth Issues"
> seems to have pretty much died out, but I've got a few questions.
> --Where in your network do you place the packet shaping box? Close to
> your attachment to the greater Internet so that all traffic goes
> through the packet shaper, close to the residence halls or other
> major sources of lower priority traffic, or somewhere else?
> --Has anyone run into performance problems due the use of a packet
> shaper? This might be general performance problems due to simply too
> much traffic going through the packet shaper or it might be
> performance problems specific to a particular application such as
> interactive video?
> --At one time you could identify most peer to peer traffic using the
> TCP or UDP port numbers in the IP packet header. More recently this
> has gotten harder since the peer to peer applications are using
> random port numbers or using the same well known port numbers used by
> other applications (port 80 is common). Here at Merit we see about
> 2/3s of the peer to peer traffic is using random or other well known
> port numbers today. Has this shift caused problems for the packet
> shaper solutions?
> --I am not sure I have this next part right, but from people's
> responses to this discussion thread it seems as if many of the
> solutions involve limiting peer to peer or other low priority
> applications to some fixed amount of bandwidth, possibly adjusted at
> different times of the day or days of the week. Is anyone trying to
> control bandwidth use in a more dynamic fashion based on total demand
> at the time (when there is less high priority traffic you allow more
> lower priority traffic and vice versa)? If so, how do you do this?
> What rules do you use?
> --Is anyone using or considered using a Quality of Service or Class
> of Service approach to these issues? With this approach the priority
> of a packet is marked (possibly using a packet shaper, but it would
> also be done by a router or an application) in the Type of Service
> (TOS) field in the IP header and decisions about what to do with the
> packet are made by routers based on how the packets are marked. This
> splits the traffic shaping work up so that different parts can be
> done at different spots or even at multiple spots in the network. The
> advantage to this approach is that each location can have more local
> context upon which to make its decisions. The QBone Scavenger
> Service (QBSS) that is available over Internet2 (but which could be
> implemented on pretty much any network) is one example of this
> approach. See http://qbone.internet2.edu/qbss/ for details.
> -Jeff Ogden
> Merit Network