AltiGen comm ACM 5.1 - Manual (Page 239)

AltiWare ACM 5.1 Administration Manual 225
C
H A P T E R
16
Setting Up IP Extensions
The AltiGen IP phone communicates with the system using SIP protocol to establish the
signaling channel and media channel (the voice steam, using RTP protocol). With SIP
implementation, the system establishes a signaling channel to an IP phone when the IP
phone is in use.
Figure 1. Concept of signaling and media channels
The media channel (voice stream) is connected between two IP phones under normal
operation. There are some special situations that require you to configure the IP phone
to connect its voice stream to the server. Please see “Setting an IP Extension” on page
229 for information.