Budgeting Traffic Access Points Correctly

What is happening
A major challenge for data centers today is to gain greater visibility of their fiber optic networks. Traffic Access Points are a very accurate and reliable way to access the data, and at the same time save on operating expenses. TAPs can be integrated into the fiber optic cabling infrastructure to passively monitor a network link.

Good to know
The relevant standards do not list TAPs as sources of loss. But they can be budgeted under the same conditions as connectors. With these additional attenuation losses, the link budget needs to be recalculated.

TAP connections have to be designed with great care. A balance between TAP loss, link length and the number of connections ensures power budget requirements for live and TAP traffic are met.

R&M laboratory measurements have proved that a data center link with a 50/50 multimode R&M TAP splitter operates for a link length of up to 400 m at λ = 850 nm, which complies with the IEEE 40G/100 Gigabit Ethernet power budget. Under the same testing conditions and using a 70/30 split ratio, 250 m were reached for the 30% link and 550 m for the 70% link. This difference must be taken into account when designing a TAP link.

The R&M Link Loss Calculator was developed to simplify the planning and design process of monitoring links (see www.datacneter.rdm.com). R&M has also published a white paper with further information (see links).

R&M’s data center cabling range includes an integrated optical analysis module for Traffic Access Points. The TAP module belongs to the family of High Density (HD) solutions. It is compatible with the HD and R&MinteliPhy hardware and facilitates scalable port diagnostics.

Help us improve. Send your feedback and suggestions to connections@rdm.com

Dr. Blanca Ruiz

By Dr. Blanca Ruiz

Senior R&D Engineer