System interfaces
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System functions and features as of R3.0
syd-0367/1.3 – R3.0 – 03.2013
2. 1. 3 SIP access
The communication server can be connected to one or more SIP providers via the 
Ethernet interface on the basic system. The communication server supports 10 SIP 
access with up to 30 channels per SIP access. One SIP Access Channels licence is re-
quired for each channel.
The communication server handles the SIP access in the same way as analogue or 
digital network interfaces, i. e. they are grouped in one or more separate trunk 
groups. The allocation to an SIP provider is defined for each trunk group. This 
means for example  that international calls can be routed via SIP providers in differ-
ent countries.
The communication server must register with a registrar of the SIP provider so that 
the SIP messages can be forwarded to the proxy server and from there to the public 
network, for example via a gateway. At least one SIP account has to be set up for 
each SIP provider. Each account contains a user name and password for identifica-
tion with the Registrar and an SIP identification number (SIP-ID). The SIP-ID is linked 
with a direct dial number so that outgoing and incoming connections can be 
made. A total of 500 SIP accounts can be set up and linked with the corresponding 
direct dialling numbers.
One SIP account per SIP provider can be set up as a default account. It can then be 
used by users without an SIP account for outgoing calls via a corresponding route 
or for incoming calls via a special call routing.
Besides the connection of communication servers to one or more SIP providers, 
several communication servers can also be networked via SIP.