IT managers needing fast network server connections could be tempted by Finisar’s new 10Gbit/s serial active optical cabling system. Called Laserwire, the product was unveiled at the recent Supercomputing 07 show in Reno, Nevada, along with Finisar’s Ethernet adapter modules, which allow Laserwire cabling to connect to legacy 10Gbit/s optical transceiver ports.
Finisar’s sales director, Jan Meise, said, “The challenge we’re addressing with Laserwire is the need for a low-weight, low-power, low-latency and high-density 10Gbit/s server connectivity from the network to the switch.”
Finisar said faster cabling was needed to cater for next-generation multi-core server boards and server virtualisation. Finisar also pointed to a trend in firms for aggregating four 1Gbit/s links to make 4Gbit/s connections.
To keep things simple, Finisar’s solution makes use of what already exists in network hardware, such as media access controllers, physical layer hardware, switch fabrics, optical transceivers and electrical interface standards. “We don’t want to re-invent the wheel,” explained Meise. Finisar also has an adapter to fit the current generation of small form factor 10Gbit/s Ethernet transceivers (XFPs).
Meise said that while the use of 10GbE fibre optic transceivers in the datacentre core is growing, there has so far been no volume adoption of 10GbE on the server connectivity side neither from an optical nor a copper perspective.
Currently, 10GBase-T standards for copper 10Gbit/s connectivity include CX-4, approved by the Institute of Electrical and Electronics Engineers in 2004, and 802.3an 10GBase-T over twisted pair copper cabling, approved in July 2006. Finisar is pushing the weight and distance advantages of Laserwire over CX-4, and is pointing to the weight and the larger bend radius of the Category 6A (Cat 6A) needed for 802.3an 10GBase-T systems.
However, telecoms test and measurement vendor Spirent calculated the total cost of ownership for a 10GBase-T link will be up to five times less than the current cost of an optical link for delivering 10Gbit/s. “A fibre-optic link currently costs anywhere between $1,850 [£900] and $3,000 [£1460], depending on the optical transceiver format. Its copper-based equivalent using 10GBase-T will cost in the region of $350,” said Spirent senior product manager Charles Seifert.
Seifert also argued that fibreoptic links require transceivers, which can be easily damaged or inadvertently lost, and pointed out that while Cat 6A can be cut to length during installation, cutting fibre-optic cable to length in the field is time consuming and difficult.
Finisar countered that the power requirement of switches needed for 10GBase-T using Cat 6A is around 10W per port, with 5W per port systems not appearing until next year. With Laserwire, power requirements are much lower, Finisar said.
Recent figures from Infonetics Research show the 10GbE market is growing fast, with annual shipments expected to increase from 300,000 ports in 2006 to more than 3 million in 2010.
