IT managers face many new challenges as they have no choice but to migrate to next-generation, faster networking infrastructure.

Managing fiber infrastructure has become a tedious task as fiber counts increase. Connectivity agility needs to be implemented from Day One to support future network reconfiguration and upgrade cycles.

What is Port Replication?

In many mission-critical applications, a backup link is required in addition to the primary link to ensure high service availability.

Port replication on active networking gear can provide highly reliable networking service that allows fast troubleshooting for connection issues and minimizes system downtime. In this scenario, the system has 100% redundancy; server and switch port usage is reduced to 50%. Additional cable and floor space can add to overall system costs.

Port Replication

Port replication with backup ports and links

What is Port Monitoring?

With the aid of network functions virtualization (NFV), which permits data processing and network services in physically separated servers with a hypervisor (virtual machine monitor), operating systems can now run as virtual machines for dedicated applications. As a result, average CPU usage can be improved considerably because the computing resource is shared by different end-users and applications.

Without adding system complexity, or increasing computing overhead to active gears, proper port monitoring in patch panel design can facilitate deployment of networking infrastructure and equipment in a timely fashion, meanwhile reducing workload and risk when it comes to reconfiguring and maintaining the system.

As a cost-effective alternative to port replication, port monitoring uses passive optical components on the ports of the active optical I/O with a proper split rate. For example, when using a passive optical splitter with a splitting ratio of 70/30, the primary path transmits 70% of the optical power to the dedicated switch port I/O; the remaining 30% goes through another optical path for real-time traffic surveillance and diagnosis on the monitor hardware.

Port Monitoring

Port monitoring with passive optical TAP (passive splitter)

Download our 10 Steps to Holistic Data Center Design white paper3 Benefits of Passive Optical Port Monitoring

Using port monitoring, data center managers can manage an entire fiber network more efficiently, thanks to several benefits.

  1. Passive port monitoring reduces deployment time. One-to-one mapping makes the job of network administrators much easier when installing, reconfiguring and upgrading active gears.
  2. Passive port monitoring reduces risk of user error and the likelihood of downtime. When a port fails, the port monitoring tool can quickly and smoothly identify its physical location, which leads to a lean, hassle-free data center infrastructure management and maintenance process.
  3. Passive port monitoring allows space for monitoring equipment with no additional expense required for high-speed switch ports. Because only passive optical components are used, passive port monitoring is bandwidth agnostic and can support speeds from 1G to more than 100G per fiber link. It also supports data center infrastructure management (DCIM) software and provisions computing and storage capacity more intelligently and efficiently with reduced failure rates and faster recovery time.

Passive Port Monitoring Deployment Considerations

A common challenge in deploying port monitoring involves additional optical loss budget. For example, a splitting ratio of 75/25 leads to an additional loss of 1.5 dB on the primary link budget.

As data rates increase, the optical loss budget will shrink due to bandwidth limitations and other transmission penalties. Only low-loss fiber cabling, assemblies and patch panels allow the implementation of optical port monitoring without jeopardizing primary link performance.

Another deployment risk involves alignment of port numbering. It is extremely important to wire fiber to the right port without mixing the paths. We recommend installing only high-quality products for one-to-one port mapping, with easy-to-recognize icons, numbering and good technical documents that provide guidance.

Belden’s TAP Cassette Solution

As a leader in high-speed data transmission and data center infrastructure solution provider, Belden developed its traffic analysis port (TAP) cassette to support optical port monitoring requirements in data center applications.

Belden TAP Cassette


The picture above represents our 32-port to 64-port TAP cassette built with premium OM4 cable and MPO-12 (Base-8) connectors. Using a common form factor, this slim TAP cassette is interchangeable with standard patch panel cassettes and can support an arbitrary splitting ratio for port monitoring in different data center architectures. Learn more about Belden’s data center solutions here.


Belden 32×64 port multimode fiber TAP cassette (pictured at right)