Document Number: GSUP1000
Product: GOSS, Rack Mount Gigabit Probe, Gigabit Probe Kit, Optical TAPs
Date: 7-18-2002
Title: Using GOSS, Gigabit Rack Mount Probe or Gigabit Probe Kit on a Switch Span Port

Using GOSS, Gigabit Rack Mount Probe or Gigabit Probe Kit on a Switch Span Port
It is possible to use any Network Instruments Full-Duplex Gigabit Product on a span port of a switch, but it is highly recommended to TAP the link between the gigabit device of interest and the DCE device (typically a switch). For more information on options for gigabit analysis and a complete description of the pros and cons of using TAPs -vs- span ports, please see the following documents:

Gigabit Options Using Observer (an overview)
Gigabit Capture Using Observer (PDF) (a more detailed discussion)

After reading either of the above linked documents, if you still need to analyze a gigabit link via the span port on a switch, this can be done with any of the Observer gigabit products in the following manner:
    1. Do not use the TAP that came with your product.
    2. Connect the straight-thru cable that came with your gigabit product (part number
        TOCSTR) from the span port on your switch to port "A" on your gigabit Observer.

While the gigabit Observer product is a passive analysis solution, the carrier signal is maintained on the send port of the gigabit link specifically to keep the port link active.