Valleys rejoice as SDSL links councils

Three Welsh councils have jointly commissioned a managed network that uses Symmetric Digital Subscriber Line to maintain broadband connections to remote sites.

The network is being built by Siemens Network Systems (SNS) and aims to comply with the government's 2005 deadline for the delivery of online public services. The councils had to use a mixture of existing and new infrastructure resources to meet tight budget constraints.

Only Denbighshire County Council has completed its installation so far. It designed a single framework for service delivery with two other councils to give itself a stronger negotiating hand in procurement. The design of the network was constrained by the wide dispersal of sites across the three authorities.

Wayne Leatherbarrow, senior systems engineer at SNS, said: "The biggest restriction was availability of bandwidth within the geographic locations. The councils wanted broadband access for all schools and libraries so they could serve as one-stop information points for the rest of the community.

"We didn't have the budget to use E1 leased lines throughout the network. The councils already had access to EPS9 circuits, so we trialled DSL and found that, over the distances we were talking about, SDSL was most suitable in maintaining bandwidth. So BT is running SDSL on its leased lines even if it doesn't realise it."

Denbighshire laid a new network commissioned from BT, which mainly consisted of E1 leased lines. Where this wasn't possible EPS9 leased lines were used, which offer 2Mbps but only over short distances.

To boost the speed between some of the more remote sites, SNS used synchronous DSL connections at both ends of the EPS9s. Leatherbarrow said that virtual private networks connections had been considered, but that leased lines had given SNS more control over quality of service on the network.

Denbighshire's Learning Stream Network is stage one in the first implementation phase, and the network will provide links to 64 schools and 12 libraries within the county; 14 of the sites will incorporate voice over IP technology.

All interdepartmental calls between Denbighshire's remote sites and central offices will now be delivered over the VoIP network without incurring charges.