A number of NHS organisations are have their own wide area network infrastuctures. Often these include one than one N3 connection. These are use to provide additional bandwidth plus usually act as resilient links in the event of one of them failing.

The on-site Nortel Contivity units provided by the Enhanced Solution are capable of being configured to take advantage on multiple N3 links.

The organisation would use at least two on-site Contivities. One acts as the primary VPN Concentrator. However, should a failure occur on any part of its main WAN link (the unit itself, the N3 link, the N3 managed router) the users can re-connect and will be routed to the Backup VPN Concentrator.

This solution enables organisations to provide higher Service Level Agreements to their users. This means that users have a higher availability service and can be guaranteed access more of the time.