Mark Main, senior analyst, at Ovum, said IP VPNs are a popular and cost-effective way for businesses to link offices around the country via a public carrier's network. "It is a flexible alternative to leased lines," he said. "From a resources perspective, businesses share a common network, but each company sees a private network."
The IP VPN operator can provide a guaranteed quality of service, which allows users to run bandwidth-critical applications such as IP telephony.
Abbey National's IP VPN replaces a mixed network comprising ISDN, ADSL and various ISPs. The internal telephone network is also being replaced by IP telephony running between branches over the VPN.
By the end of October, 9,500 Cisco IP telephony handsets will be rolled out across all branches in the UK.
BT Transform provided the networking services across 900 locations and modernised the local area networks.
The legacy Token Ring Lan, based on Category 3 cabling, is being replaced by switched Ethernet and Category 5 cabling to cope with higher voice and data throughput. The branch network is also being upgraded from a 64kbps link to 512kbps.