The Global Lambda Integrated Facility is a worldwide laboratory for application and middleware development that utilises a network of interconnected optical wavelengths (also known as lambda grids). In fibre optic telecommunications, wavelength-division multiplexing is a technology that enables a single optical fibre to carry multiple signals by using different wavelengths (or colours) of laser light for each of them. This allows for a significant increase in transmission capacity, bi-directional capability, and physical separation of channels.
GLIF takes advantage of the cost and capacity advantages offered by optical multiplexing, in order to build powerful distributed systems that utilise processing power, storage, and instrumentation at various sites around the globe. The aim is to encourage the shared used of resources by eliminating a lack of network capacity as the traditional performance bottleneck.
GOLEs, Lambdas and Lightpaths
The GLIF network is currently based around a number of lambas, contributed by the GLIF participants who own or lease them, which are interconnected through a series of exchange points. Lambdas are dedicated high-capacity circuits based on optical wavelengths, and which terminate at exchange points known as GOLEs (GLIF Open Lightpath Exchanges).
GOLEs are usually also operated by GLIF participants, and are comprised of equipment that is capable of terminating lambdas and performing lightpath switching. This way, different lambdas can be connected together, and end-to-end lightpaths established over them. Normally GOLEs must interconnect at least two autonomous optical domains in order to be designated as such.
A lightpath is a communications channel (virtual circuit) established over lambdas, that connects two end-points in the network. It can take-up some or all of the capacity of these lambdas, or indeed can be concatenated across several lambdas. Lightpaths can be established using different protocol mechanisms, depending on the application.
The GLIF participants are organisations that share the vision of optical interconnection of different facilities, and who voluntarily contribute network resources (equipment and/or lambdas) and/or actively participate in activities in furtherance of these goals. Seamless end-to-end connections require a high degree of interoperability between different transmission, interface and service implementations, and also require harmonisation of contracting and fault management processes. The GLIF Technical and Control Plane Working Groups are technical forums for addressing these operational issues.
Connecting to GLIF
The network resources that make-up the GLIF are provided by independent network operators who collaborate to provide end-to-end lightpaths across their respective optical domains. GLIF does not provide any network services itself, so research users need to approach an appropriate GLIF network resource provider if they wish to obtain lightpath services.