The telecommunication devices connectable to the private IP network exchange (LE)
have Ethernet interfaces.
The IP telephones of exchange (PABX, CM) manufacturers are compatible with ISDN
in their services.
These telephones are connected to the exchange via the so-called "Ethernet"-inteface
which provides the following services:
- Duplex signal transmission capability. Speech samples are delivered between device and exchange in Ethernet frames, actually in RTP packets located in the frames.
- Signaling tarnsmission capability. Signaling messages are delivered between device and exchange also in Ethernet frames.
Signaling messages from multiple different protocols (e.g. H.323, SIP, Stimulus) can be delivered by packets.
IP telephone devices provide more services than their analogue counterparts.
On of the technical basis of this is the high capacity signaling channel.
Most of the services are assigned to the function buttons of the device, which allow to use the device convenient.
IP telephones has local feeding.
Picture of an IP telephone:
Block diagram of IP telephones:
