AltiGen MAXCS 7.5 Softswitch Deployment Guide - Manual (Page 19)

MAXCS 7.5 All-Software Solution Deployment Guide Page 19 of 37
Does not support G.729 No codec is enforced.
Outgoing Calls, 3 rd -Party IP Phones - Preferred Codec G.711 Mu-Law
First SIP Invite Request Content Codec Used for the 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, IP Phones
Because 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 IP phone, the system follows the IP Codec table in Enterprise
Manager. All 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.
Outgoing Calls, IP Phones
Preferred Codec Codec Used for the 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.
Step 8: Configure the SIPSP Virtual Board
A VoIP connection typically consists of two parts.
Signal Channel – Sets up and tears down a call using protocol. SIP protocol is used in MAXCS to build a
signal channel between the server and the IP phone.
Media Path – Encodes, transmits, and decodes voice for both parties.
The purpose of the virtual board SIPSP is to build signal channels for different connection types, IP extensions,
SIP Tie Trunks, and SIP Trunking from ITSP. Each channel will have its channel ID similar to channels on a
Triton extension or trunk board.