The R850 appliance provides failover capabilities for digital (T1, E1, J1, PRI, BRI) circuits. Lines from the telephone company are terminated to the R850, which then delivers service to Digium interface ports on the active server.
In the event of a hardware or software fault on primary, the R850 redirects all circuits to the backup. Control signaling is handled via USB ports which also provide power to the R850, saving energy over the lifetime of the appliance.
The R800, combined with clustered primary and standyby Asterisk servers, provides a fully redundant communications solution. Lines from the telephone company are terminated to the R800, which then delivers service to Digium interface ports on the active server. Third-party applications monitor the health of the primary server and provide mirroring of the Asterisk config files.
In the event of a hardware or software failure on the primary Asterisk Server, it will be removed from the cluster and the R-Series is instructed to move the PSTN circuits to the standby. The standby server will assume the role of primary within seconds and without loss of services such as voice mail, phone registrations, etc.