User guide

VoIP SIP VoIP SIP Servers, Users & the Forwarding Data-
iMG/RG Software Reference Manual (Voice Service)
6-20
The system will attempt to register the local users on all the location servers available in the location server list
(see VOIP SIP LOCATIONSERVER LIST command) until the first registration phase achieves a positive result.
Once a successful registration with a server has been achieved no further registration requests will be per-
formed even if other location servers are defined.
In the case that more than one location server is defined in the system, it's possible to set a location server as
Master: all registration requests will start with the master location server, independently of the position of that
server in the location servers list. In the case where registration with the master location server fails, the Loca-
tion Server list will be used examined to find alternative location server(s) to which registration requests will
then be sent.
Note: If no location servers are defined, the iMG uses the server addresses defined in the Proxy Server list
instead.
Note: If users are defined without specifying a user domain (see VOIP SIP USER CREATE command), the
user domain will automatically be associated with the location server address where the user is
registered.
6.2.2.1.2 Proxy servers
When an outgoing call cannot be handled by a local number or a well defined forwarding rule it must resolved
by an external proxy server. In this case the SIP module needs to know which proxy server should be used.
The VOIP SIP PROXYSERVER CREATE command is used to inform the system of the proxy servers that can be
contacted when an outgoing call is to be established.
Similarly to location servers, it is possible to define more that one proxy server in order to increase system
reliability.
The system will attempt to contact all the proxy servers available in the proxy server list (see VOIP SIP PROX-
YSERVER LIST command) until the first server answers to the INVITE request. In that case no further INVITE
requests are sent to the other proxy servers even if the called user cannot be reached.
In the case that more than one proxy server is defined in the system, it is possible to set a proxy server as Mas-
ter. All INVITE requests will start with the master proxy server, independently of its position in the proxy serv-
ers list. In the situation where the Master proxy server cannot be reached, the Proxy Server list will be
examined to find alternative proxy server(s) to which INVITE requests will be sent.
Note: The Proxy Server is also used as registration server if no location servers are defined.
Note: If users are defined without specifying a user domain (see VOIP SIP USER CREATE command) and no
Location Servers are defined, the user domain will automatically be associated with the proxy server
upon which the user is registered.
6.2.2.2 Users
The system is designed to support up to 100 entries, shared between users and forwarding rules.
Users are defined by the VOIP SIP USER CREATE command.