The system is a network router. In this role it can connect users on its LAN to remote services by using WAN links and telephone trunk connections. It can also allow users to dial-in and then act as if they were using a PC on the LAN.
As well as being a network router, the system is a telephone system. These dual roles allow it to support a range of functions that involve traffic between the network and telephony interfaces. These functions use internal data channels. The number of internal data channels that can be connected from the system's LAN interface to its telephony interface at any time is restricted.
An internal data channel is a connection between the system's telephony and LAN interfaces. For example a Voicemail connection, an internet connection or a RAS user.
Calls using a VCM channel do not use a data channel.
The number of data channels in use does not necessarily match the number of users:
Several LAN network users, browsing the internet using the same service to an ISP would be a single data channel.
Several dial-in network users would each have a separate data channel.
The maximum number of data channels that can be simultaneously in use for voicemail is restricted. These channels also require entry of an appropriate license.
The restriction depends on the type of control unit being used.
System Control Unit |
Internal Data Channels |
Maximum Data Channels for Voicemail |
Small Office Edition |
18 |
10 |
IP403 |
18 |
10 |
IP406 V1 |
24 |
20 |
IP406 V2 |
40 |
20 |
IP412 |
100 |
30 |
IP500 V2 |
48[1] |
40 |
Reduced to 44 when an IP500 V2 4-Port Expansion card is installed.