[nsp] bandwidth manager

[Tony Wasson]

> On Thu, 1 Aug 2002 19:08:18 -0700 (PDT) Benjie Ko <gerwalk1@yahoo.com>
wrote:
> > Is it possible to put a transparent ethernet bridge
> > (bandwidth manager) between two cisco switches doing ISL
> > trunking?

I think your bridge will be confused because the Ethernet Addresses won't be
at the front of the frame. The ISL format is like this:

ISL Header | Original Frame | FCS
http://www.cisco.com/warp/public/473/741_4.html

ISL may work if the bandwidth manager only allows 'n' frames in each
direction. I'd imagine the box you want is more sophisticated; you can
probably configure bandwidth based on L3 or L4 information. Once ISL has
shifted your frames, the bandwidth manager won't find the L2 or L3
information where it expects.

802.1q would work in this situation, but you might see giant sized frames
come through the bandwidth manager. I have used 802.1q over some 10Mbps
radio links where we HAD to allow 2 VLANs. As long as your bandwidth manager
won't disable ports due to errors, you'll be all set.


Hope this helps!
Ton Wasson