AltiGen MAXCS 7.0 Update 1 ACM Administration - Manual (Page 221)

Media Channels
MaxCS 7.5 Administration Manual 205
• SIP Extension Channel – Establishes a logical channel relationship with other analog and MobileExt
ports (displayed on the SIPSP board configuration, Channel Mapping List).
• SIP Extension Channel Activation – Associates an extension with a SIP Extension channel when IP
phones register to the system (displayed in the Extension View window).
Media Channels
A media channel is an RTP channel that connects system-to-phone, or phone-to-phone, system-to-system to
carry the digitized voice stream. The codec resource on the VoIP board will be allocated dynamically based on
connection types. If both end devices are IP phones, the media channel can be connected from IP phone to
IP phone using the IP phone’s codec, except when the following is true:
• SIP trunk is used
• Codecs at two end devices are mismatched
• Extension has Agent setting checked
• Voice recording is enabled at the IP extension
• A NAT router exists between MaxCS 7.5 and remote IP phone
• SIP supports a direct connection of the voice stream between IP phones.
The media channel implementation consists of the following elements: