New York Presbyterian Hospital has dumped its WAN service provider and lit up leased dark fibre with dense wavelength division multiplexing gear that saves money and enables the hospital to grow its network as it adds more high-bandwidth applications.

Leasing fibre from a New York-area network consortium for research and educational organisations, rather than buying network services from Verizon, provides more bandwidth and saves the hospital $151,000 per year, according to Leo Bodden, director of the hospital's network group. Adding more and faster lasers with its new optical gear give it nearly unlimited bandwidth for future needs.

With two strands of fibre, the hospital uses 21 wavelengths to provide connections ranging from 10Gig Ethernet to Fibre Channel on a core network stretching 41 miles around New York City. The network can support up to 32 separate 10Gig bit/sec wavelengths - enough bandwidth for a long time, Bodden says.

The addition of high-bandwidth traffic, including medical imaging, a mirrored data centre and storage-area networking (SAN), have pushed the limits of New York Presbyterian's network since 1999.

At that time, the hospital had filled up its OC-3 ATM network on three campuses in New York City, so it considered buying an OC-12 SONET network from Verizon.

But before the contract could be awarded, the hospital realised the OC-12 network would be overloaded by the time it was built, so it revised its plans upward to an OC-48 network.

That network never went to bid either because the hospital instead built its own DWDM network, built on Adva FSP 3000 optical switches.

It then took the hospital three years to put out its bids for OC-48 SONET replacement in 2002. The hospital was planning a high-bandwidth medical imaging service called Picture Archiving and Communication System and creating a mirrored data centre at 168th Street, so it needed room.

By that time, the network consortium - New York State Education and Research Network (NYSERNET) - proposed leasing dark fibre in New York City and re-leasing it at relatively low cost to members. The hospital had tried to lease dark fibre but couldn't afford it.

The hospital bought in to the NYSERNET proposal and pays NYSERNET $542,000 per year for the fibre, Bodden says. That's down from the $693,000 it paid Verizon last year for its OC-3 network that had been supplemented with DS-3s until the new network came online earlier this year.

The Adva DWDM gear cost $1.5 million to buy, as opposed to the other bid the hospital got - $4 million for Cisco 15454 optical gear. Besides the price, the hospital preferred the Adva equipment because if one node fails, it passes traffic through as if it weren't there, and the other nodes still can receive traffic. But Cisco's gear terminated all traffic at every node, not letting traffic through, Bodden says.

This was a key consideration because 38th Street has only battery backup, and a power outage could run down the battery and bring down the node, he says.

He also says he liked the simplicity of the Adva FSP 3000 gear. The Adva lasers are set to be slightly over-powered to work without adjustment even under slightly changing conditions. The Cisco gear tunes itself on an ongoing basis to adapt to changes.

So far the hospital has lit up 21 wavelengths on the network, two at 10Gbit/sec, carrying 10Gig Ethernet and Fibre Channel, and others at 1Gig. Bandwidth can be boosted by increasing laser speed or adding more lasers, Bodden says.