Bidirectional Fiber Optic Test Links Stress 40 and 100Gigabit Ethernet Optical Network Equipment

Delaire USA's new 40GE and 100GE bidirectional fiber optic test links allow full duplex physical layer system tests

Delaire USA’s 8800 Family of Fiber Optic Test Links for Multi-Channel Bidirectional Testing provides approximations of worst-case fiber links to verify the ability of high-speed optical network equipment to operate at the limits of cables defined by the 802.3 Ethernet standard.

In the 8800 each channel is composed of a pair of fiber links, one transmit and one receive.  This bidirectional test link architecture supports simultaneous multi-channel testing of both transmit and receive physical layer functions of a device (router, switch, server, etc.), while operating under worst-case fiber bandwidth conditions.  The 8800 can be used to test performance (e.g., BER) and/or functionality (e.g., link configuration) of a single device’s transmitter and receiver or to test the interoperability of two devices - all while operating under worst-case fiber bandwidth conditions.

Jeff Lapak, Associate Director at the University of New Hampshire Interoperability Laboratory said, 'The Delaire USA bidirectional fiber optic test link lets us easily connect devices together over a worst-case cable plant in order to verify interoperability under stressful optical conditions.  Having all four channels under-stress at the same time allows for rapid and robust interoperability testing on devices like routers, switches, and transceivers.’

The 8800 supports both multi-mode and single-mode fiber applications.  It is fully configurable to meet custom requirements where the customer defines the operational parameters of the system and can therefore be used in other standards such as OTN, InfiniBand and Fibre Channel.

As a multi-mode example, the IEEE 802.3ba specification defines a maximum operating distance of 150 m for 40GBASE-SR4 over OM4 fiber with an Effective Modal Bandwidth (EMB) of 4700 MHzkm (at 850nm).  To meet this requirement, the full duplex 8800 contains four bidirectional channels (eight links) of identical fiber cut to the same length (spooled to within an accuracy of +/- 0.06%) terminated with MTP/MPO connectors.  The actual length of each link is selected to provide the worst-case link bandwidth specified in the standard. 

For further information, contact Lorraine Hallock 732-528-4520 or visit