7
Figure 4. Retrofit example: 10GE channel with 50/50 TAP module replacing
MPO/LC module at central cross connect
A quick check of the Performance Specification reveals that the 10GBASE-S power budget
supports both 50/50 and 70/30 split ratios for the main channel. The ability to support a
50/50 split ratio also permits the monitor equipment to use minimally standards-compliant
transceivers, and therefore the monitor channels may also be designed using the same
topology limit tables as the main channel. This choice offers a straight forward design that
requires no design consultation with the monitor equipment company. In comparison, the
selection of the 70/30 split ratio, while improving the signal strength of the main channels,
requires better than minimally compliant transceivers in the monitor gear and therefore
necessarily involves consultation with the monitor gear company for design limits. Here we will
illustrate the design approach using a 50/50 split ratio TAP module.
Looking at Figure 4, determine the main channel length by adding up the cord and cable
lengths that form the main channel from left to right:
10m+80m+5m+80m+10m=185m
The length of the monitor channel from the left side is:
10m+80m+5m=95m
The length of the monitor channel from the right side is:
10m+80m+5m+5m=100m
In this network configuration, the main traffic channel has four MPO connections and four
LC connections (the connections to the active equipment are not counted), and the channel
length is 185m. The longer monitoring channel, which is the right side in this case, has three
MPO connections and three LC connections, and the channel length is 100m. The shorter
monitor channel, which is on the left side in this case, has three MPO connections and one
