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Passive Optical Tapping: 5 Often Overlooked Advantages

Safely connecting monitoring and security tools allows IT managers visibility into network traffic flows. Network visibility is critical to protecting network infrastructure, securing confidential information, complying with information protection regulations and planning for future growth.


There are a wide variety of TAP options for connecting these critical tools. Intelligent TAPs, Hybrid TAPs and Packet Brokers offer many advanced tool efficiency and traffic management features for complex networks. Passive Optical TAPs do not offer these advanced features but offer other advantages when used in the right application.


No Power Required

The entire light budget on an optical link is not required to pass live traffic. Optical TAPs split the light coming in from optical links in order to create a mirror copy of live network traffic. The splitter, therefore uses some of the unused bandwidth to send a copy of the entire traffic stream to a tool while allowing the live traffic to pass through the network without delay or degradation. This splitting of light is accomplished with specialized mirrors and does not require any power or electronics.


High Port Density

Because there are no electronics in an optical TAP, the rack space required is minimal. Optical taps can achieve port densities of up to 24 ports per Rack Unit (RU). In applications like mobile carrier cell sites, where space is limited, optical TAPs serve to provide required visibility while using very little real estate in a confined area.


Cloud and Colocation environments, where many clients are using the same physical space, is another application where the density of optical TAPs can benefit the carrier. Optical TAPs can be modular and independent but reside in the same rack. This allows the Cloud or Colocation carrier to manage discreet customer networks with complete physical separation while fully utilizing existing rack space.


Budget Friendly

As noted, Passive Optical TAPs require no active electronics or power. The product assembly is less complex and therefore less expensive to manufacture. In large network applications that require a variety of tools, passive TAPs can save CAPEX by allowing multiple tool connections at a very reasonable cost. More budget can be spent on the sophisticated tools that protect the network and less on the access to traffic visibility.


Flexible Utilization in the Network

There are many design options available for optical taps. Depending on the distance between the network end points, either single mode or multi-mode fiber may be utilized.


For single building or campus environments, multi-mode fiber (MM) is a low cost option that can be designed for distances up to approximately 1000 meters at 1Gbit/second or 550 meters at 10Gbit/second. For longer distances and faster speeds, single mode (SM) fiber may also be considered. The single mode fiber limitations depend on factors such as transmission distance, transmission speed and transmission frequency. Typically, single mode fiber uses frequencies in the 1300nm and 1550nm range. Multi-mode fiber transmission is usually 850nm and 1300nm. When choosing fiber taps it is critical for the TAP to match the type of fiber and transmission frequency of the connected network links.


Light budget is another consideration when purchasing optical TAPs. When splitting the light budget (allocation between live network and tools) there are many available options. Depending on speed and bandwidth needs, the light may be split 90% in the network and 10% to the tools or any increment in between. Many common splits, such as 50/50, 60/40, 70/30 are readily available off the shelf while other custom splits may also be ordered as needed.


Directional Break-Out

Traffic flows through the network in two directions, from end point A through the network to end point B and also from end point B back through the network to end point A. Many traffic monitoring and analysis tools find it helpful to separate, or break out, the directional traffic. In other words, it is helpful, when analyzing traffic, to understand the A to B traffic separate from the B to A traffic. Problems from switches, end points or applications at one end may be more easily identified when the directional traffic flow is broken out. Optical Fiber TAPs always break out discreet streams of traffic in each direction.


Sometimes a Mix is Best

Intelligent TAPs, Hybrids and Packet Brokers play an important role in connecting monitoring, security, compliance and performance tools to network links. The broad feature sets of Packet Brokers provide many advantages that help monitoring tools operate more effectively and allow managers to develop more sophisticated reporting options. Optical TAPs, however, also play an important role in simpler network environments and when connected to the front end of links being fed into Packet Brokers.


Network Critical is a global leader in the design, development and manufacturing of Passive Optical TAPs as well as the more feature rich intelligent TAPs and Packet Brokers. The best way to develop your comprehensive visibility strategy is to discuss architecture and options with the visibility experts at www.networkcritical.com/support. They will be happy to discuss your requirements and offer options suitable for all networks from SMB to Mobile Carriers.


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