The 10-year deal will deliver a system to handle about 2.5 million requests for information every year.
The contract covers supply and maintenance of telecoms and IT equipment and the design and scope of NHS 24 systems as well updating equipment over the contract period.
BT will design and fit out three contact centres which will be linked to ensure an instant response to callers, wherever they are calling from. The system is based on a BT managed virtual private network and will be converted to voice-over-IP technology at a later date.
To give redundancy BT is providing routes to each contact centre via two exchanges for each location, as well as an overlaid 0845 network to cope with potential surges in demand in the case of a wide-ranging public health emergency which might generate millions of calls.
The service aims to integrate with out-of-hours GP co-ops, GP practices, A&E departments and the ambulance service so that patient data can be immediately transferred to where it is needed.
Levels of integration will vary, though, as the readiness of legacy systems differs across these organisations. Out-of-hours co-ops will be integrated within 15 months, while A&E departments will have only e-mail contact for the foreseeable future because of the diversity of their legacy systems.