9
Figure 5. Example 8GFC channel with TAP placed near SAN switch.
A quick check of the Performance Specification reveals that the minimally standards-compliant
8GFC power budget for MMF supports only the 70% output of a 70/30 TAP module for
the main channels. The 30% output for the monitor channels requires better than minimally
standards-compliant transceivers in the monitor gear and therefore necessarily involves
consultation with the monitor gear company for design limits for the monitor channels. The
intended MMF bandwidth grade (i.e. LazrSPEED 550 (OM4), LazrSPEED 300 (OM3)), the
monitor channel lengths and maximum channel losses will be required by the monitor company
to perform the analysis. Section 5 provides guidance on how to determine the maximum
channel loss using the
SYSTIMAX Solutions Link Loss Calculator
2
.
Looking at Figure 5, determine the main channel length by adding up the cord and cable
lengths that form the main channel from left to right:
10m+90m+10m=110m
The length of the monitor channel from the storage array side is:
10m+90m+10m=110m
The length of the monitor channel from the SAN switch side is:
10m+10m=20m
In this network configuration, the main traffic channel has two MPO connections and two
LC connections (the connections to the active equipment are not counted), and the channel
length is 110m. Table 3 is an extract from the
SYSTIMAX InstaPATCH 360 Fiber Tap Solutions
Performance Specifications—Volume Five
for 8GFC on LazrSPEED 550 and the 70/30 split
ratio TAP. The cell at the intersection of 2 MPOs and 2 LCs indicates a supportable distance
of 115 m, which is greater than the 110 m length of the main channels, so the design is
supportable with LazrSPEED 550 cabling for the main channels.
