Benutzer:Soeren/Phonesystem2012

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The current phone system uses two Fritz Fon 7150 Boxes, one of them is directly connected to the external ISDN bus, the other one is connected to it via ethernet. The ethernet connection

-- UK0 -- NTBA -- ISDN S0 -- Fritz!Fon 7150 --> DECT (Base 1)
                                    |
                                     `-- SIP -- Fritz!Fon 7150 --> DECT (Base 2)

Due to the nature of the S0 bus, calls may not be transferred from one device to another without occupying the bus (thus blocking it for incoming calls). For this reason, one of the base stations is linked to the other one via ethernet. Base number 1 hosts a SIP server (dtmfbox), while the other Box registers to it - this way the amount of internal and/or conference calls is no longer limited by the capabilites of the ISDN S0 bus, but by the capabilities of the DECT base station (which supports 2 voice channels at a time).

Cells & Range

Base station number 1 is located in the basement, serving the basement and lecture room, while base station number 2 is standing on the table in the lounge and serves as base station for the workshop. The handsets from the good old Gigaset are registered to both base stations and will automatically choose the best one, but they don't support taking a call from one cell to another. All other handsets are registered to a fixed base station.

VOIP service

As mentioned above, the boxes are connected to one another via SIP. Incoming calls on the ISDN line are forwarded from base station number 1 to the other one.

Planned Services / TODO

• Assign fixed numbers to handsets
• Port the Asterisk-phone-reminder to dtmfbox
• external VOIP connectivity (if internal resources allow)