1xN optical switches have one input and multiple outputs. The input light can be switched to any one of the output at any given time. n(1xN) optical switches have multiple(n) such 1xN switches in single enclosure controlled by one network management module.

1xN or n(1xN) switches are used by development/test engineers or test lab automation systems to time share one expensive optical device with many other optical devices. It can save thousands of dollars in capital equipments spending by allowing effective use of under-utilized expensive optical equipments. Since these are Layer 1 switches you don't need expensive transceivers (for eg. 10GE SFP) for the ports. The popular switch models in this category include OS214 (1x4 duplex or 2x8), OS218 (1x8 duplex or 2x16) and OS414 (4(1x4) duplex or 4(2x8)). These switches provides transparent optical layer connectivity which means it can be used with any protocols (Fibre Channel, Ethernet, SONET etc.) and speed (1G,4G,10G,40G etc.), as opposed to O-E-O (optical electrical conversion - 2R/3R) devices which need expensive transceivers for each port/speed/protocol. The transparent optical layer connectivity allows unit under test to be tested from physical layer without introducing another conversion layer in between. Typical application involves sharing an expensive 10GE BERT or a protocol analyzers with 10GE Ethernet uplinks or OC192 SONET/SDH capable devices in production automation and test environments; Another application involves sharing an expensive DWDM or Fibre Channel switch with other DWDM or Fibre Channel devices in test and development environments.

The traditional 1xN switches available in the market today are not directly manageable through network, users need to have dedicated computer and software driver to connect to their GPIB or RS232 management interface which not only increases total cost of ownership but also restricts access to single user. GPIB and RS232 pose severe issues to use in today's complex regression tests and test automation environments where multiple users or applications need to share the same resource. Moreover the duplex functionality doesn't normally come in the standard configuration, either you have to custom order or connect two such 1xN devices in parallel and go through cumbersome configuration and management. Another problem with traditional 1xN optical switch is that they can’t be cascaded. This limits the scalability of such device to its physical size and electrical characteristics apart from its optical characteristics like insertion loss. You could end up spending more on new equipment to replace the old one when your business expands.

For instance the OS214 allows users to configure many OS214 devices in series, only limited by the optical devices transmit power and OS214s total insertion loss, to share many more optical devices. The following diagram shows how two OS214 switches can be connected to get one duplex 1x7 virtual switch.

For more details on os214, click here

For more details on os414, click here