3
Introduction
The need for real-time network traffic monitoring in today’s intelligent data center has become
compelling. Data center network administrators need to gain better visibility of their networks,
optimize the performance of mission-critical applications and, more importantly, secure their
networks.
In fiber-optic networks, a traffic access point (TAP) can be integrated into the fiber cabling
infrastructure, enabling network traffic monitoring from physical layer (layer 1) and above
in real-time fashion with zero packet loss. Because TAPs continuously pass all traffic running
between the endpoint network devices with zero latency—while duplicating that exact same
traffic to the monitor ports simultaneously—TAPs are one of the most efficient ways to monitor
traffic and network link quality in data center and telecom carrier networks.
This design guide will help you understand and design fiber cabling systems using CommScope
SYSTIMAX
®
InstaPATCH
®
360 TAP solutions to support applications and enable real-time
network traffic monitoring at the same time.
How Does a TAP Work?
TAP modules provide an important feature for data center monitoring and management. A TAP
module is a compact package of fiber-optic couplers or splitters that can be used to passively
divert a fixed percentage of light energy away from main transportation channels as a way
to monitor the traffic status or content in real time without disrupting the main channel traffic.
The optical couplers or splitters inside a TAP module are the key components that split the light
energy from the input port into two output ports according to designed split ratio.
Figure 1
shows example signal paths of 12-fiber multimode fiber (MMF) TAP Modules. On the
right side of the diagram the rear surface of the TAP modules provide one Multiple-Fiber Push-
On/Pull-off (MPO) connector serving the main traffic channels for connecting to a trunk cable,
and another MPO connector (red) serving the monitoring channels for connecting to monitoring
equipment via MPO-LC array cords. On the left side of the diagram the front surface of the
modules provide 12 LC receptacles for patching.
Couplers are unidirectional components and are arranged in an alternating sequence for
duplex transceiver connectivity at the LC connectors. As shown in the upper part of Figure
1, Channel 1 of the LC connectors receives traffic from Channel 1 of the MAIN MPO port
after a portion of its optical signal is split into Channel 1 of the TAP MPO connector. Other
odd-numbered LC connectors follow the same signal flow. The lower part of Figure 1 shows
Channel 2 of the LC connectors, which serves only for signal input, and its signal is split
between Channel 2 of the MAIN MPO and the TAP MPO connectors. Other even-numbered
LC connectors follow the same signal flow.
