[SR-Users] kamailio in a multi-site configuration

Hi everyone i am installing Kamailio to scale asterisk on a remote hosted server in a way to manage calls dialogs in a real-time fashion. (and to manage many customers) Several users (maybe 80) are working at the head-office and i want them register their hardphone on the remote Kamailio Ipbx, to free them of ours end-of-life PABX (alcatel-Lucent). Can kamailio help me to achieve that ? What kind of software have I to install locally (mysql to replicate the master mysql db? a replicated asterisk instance?) ? Taking into consideration disaster recovery plan What could be my options to maintain internal call if my internet provider get down by exemple. thx you for your idea. Sébastien BRICE VoIP, Support et Intégration