AltiGen MAXCS 7.5 New Features Guide - Manual (Page 15)

MaxCS 7.5 New Features Guide Page 15 of 22
Preferred Codec is G.711 Mu-Law
First SIP INVITE Request Codec Used for Call
Supports G.711
The IP Codec table of Enterprise Manager is ignored. The system uses
codec G.711 to negotiate with the endpoint.
Does not support G.711 No codec is enforced.
If the source extension is enabled for Fax-Over-IP (FoIP), then no codec is enforced.
Codec Preference – Outgoing Calls, AltiGen IP Phones
Because AltiGen IP Phone SIP call requests are always from MAXCS, the behavior is different from calls from third-
party phone extensions.
When a user makes an outgoing call from an AltiGen IP phone, the system follows the IP Codec table in Enterprise
Manager. All AltiGen IP phones support G.729 and G.711 Mu-Law.
When the Codec Preference feature is enabled, the system uses the following logic for handling outgoing SIP trunk
calls.
Preferred Codec Codec Used for Call
G.729
The system modifies the IP phone’s codec in the RE-INVTE SDP body with G.729
codec. After the modification, MaxCS must pick G.729 and G.711 codecs as the
preferred codecs to negotiate with the endpoint.
G.711 Mu-Law
The system modifies the IP phone’s codec in the RE-INVTE SDP body with G.711
codec. After the modification, MaxCS must pick G.711 and G.729 codecs as the
preferred codecs to negotiate with the endpoint.
If the source extension is enabled for Fax-Over-IP (FoIP), then no codec is enforced.
Media Enhancements
The following media enhancements have been added for MAXCS 7.5:
• Media Pass-through
• T.38 Pass-through
• Fax Support
• Fax Routing
Media Pass-through (HMCP)
Another enhancement for system performance and voice quality is the Media Pass-through feature. This feature
applies only to HMCP Softswitch systems; it is enabled by default.
While the Media Pass-through feature is enabled, the HMCP driver doesn’t need to do encoding and decoding on
both channels. This approach has the following benefits: