User guide

9
9 Additional Features
9.1 High Availability
9.1.1 Linux HA-based Failover
AMCC supports Linux HA-based failover. There are two dual mode servers running the high availability
application to act as a hot standby of each other. One of the servers providing dual mode service is
called the primary server and the other one acting as its standby is called the backup server. The
backup server is continuously sensing the status of the primary server ensuring its availability. In case
the primary server goes down, the backup server takes over its role. This is called failover and it occurs
within a few seconds.
The synchronization of the user data between two AMC Controllers is organised in a redundancy
configuration. In such a configuration there are two appliances, one serving as a master and the other
serving as slave. The slave will obtain its configuration from the master server. Therefore, this is not a
real synchronization but rather having a master containing the configuration. The slave will keep a copy
of the configuration ready to fill in if the master fails. This applies only to the FMC part of the
configuration. Functions such as IP addressing etc. are considered separately. This automatically
synchronized configuration includes all users, endpoints and registrations, numbering profiles, etc.
The synchronization is done by directly accessing the configuration database of the master server. All
changes of users, endpoints or registrations will become effective immediately and will therefore also be
scheduled for synchronization right after pressing "Save" in the AMCC Management Web GUI. In order
to lower the network load, several changes are collected and then synchronized in one step. It can take
up to 3 minutes until all changes have been properly synchronized to the slave device.
Configuration: The AMC Controller displays a "Database is currently not available" message on the
pages TELEPHONY and FEATURES if it is run in slave-mode. The AMCC Database will not be
available for changes and new data if database synchronization is ongoing and the AMC Controller is
used in slave mode. All FMC services will be rendered by the master. Therefore, changes of
registrations, user accounts, etc. can only be done on the master-AMC Controller. The data on the
slave-AMC Controller will be synchronized (refreshed). If the master-AMC Controller fails, the slave-
AMC Controller will take over. Only then, data modifications can be done on the (former) slave.
9.1.2 General Information
To configure both, master and slave, a network connection has to be set up. In theory a standard routed
connection is enough, but since this feature is used in conjunction with VRRP, you need to have a
connection supporting multicast requests, usually a switched connection.
9.2 AMC 3 Security
The AMCC offers services for enterprise telephony. The normal case is that it is placed in a closed
network with end to end security. The AMCC offers SIP authentication based on message digest. An
open source programme for filtering the by firewall offered tables, called iptables, is included and can
be configured if needed. Usually, the enterprise has its own security measures and the AMCC does not
play any critical role in enhancing the system or network security. Please see “User Guide AMC
Controller” for more information.