In case of Internet access line failures in one of the Internet access lines within the IP tunnel, Virtual Leased Line (VLL) recovers the ongoing session by redistributing the load over the available access lines, even for the sessions in progress, without loss of data integrity. This means your office to office VPN will be kept alive even during individual WAN failures. Improved network reliability – Automatic failover protects against failures of one or more access link outages, as it will not cause failure of the aggregated access link as long as at least one access link is still active, resulting in less downtime for the connection between BBNA devices. Transparent Installation – The existing Local Area Network in the head-quarter office or the branch office/colo does not require any changes. All the installation and configuration is handled through the BBNA user interface.