H.323 Line VoIP Settings

Last Updated : Aug 30, 2026 |
Navigation: System SettingsLineAdd/Edit Trunk LineH323 LineVoIP Settings
Prolog information
Metadata
Keywords:
Resource Id: line111
This form is used to configure the VoIP setting applied to calls on the H.323 line.

Configuration Settings

These settings can only be edited online. Changes to these settings does not require a reboot of the system.
Field
Description
Gateway IP Address
Default = Blank
Enter the IP address of the gateway device at the remote end.
Port
Default = 1720
The H.323 line is identified by the IP Address:Port value. Specifying a unique port value for this IP address allows multiple lines to use the same IP address.
Codec Selection
Default = System Default
Set the supported codecs. Where possible, Avaya recommend that you use the same set of codecs for all IP Office systems, lines, and extensions.
The options are:
  • System Default - Use the codec list set in the system settings.
  • Custom - Configure a list of codec preferences for the line.
    • You can move codecs between the Unused and Selected sets and change the order of the codecs.
    • The codecs available are set by System SettingsSystemVoIP. The possible codecs are:
      • OPUS - Supported on Linux-based IP Office systems only.
      • G.711 ALAW/G.711 ULAW
      • G.729
      • G.723.1 - Supported on IP500 V2 systems only.
      • G.722 64K - Supported by Linux-based IP Office systems and on IP500 V2 systems with IP500 VCM, IP500 VCM V2 or IP500 Combo cards.
Supplementary Services
Default = H450.
Selects the supplementary service signaling method for use across the H.323 trunk. The remote end of the trunk must support the same option. The options are:
  • None: No supplementary services are supported.
  • H450: Use for H.323 lines connected to another PBX or device that uses H450.
  • QSIG: Use for H.323 lines connected to another PBX or device that uses QSIG.
Call Initiation Timeout
Default = 4 seconds. Range = 1 to 99 seconds.
This option sets how long the system should wait for a response to its attempt to initiate a call before following the alternate routes set in an ARS form.
VoIP Silence Suppression
Default = Off.
When selected, this option will detect periods of silence on any call over the line and will not send any data during those silent periods. This feature is not used on IP lines using G.711 between systems. On trunk's between networked systems, the same setting should be set at both ends.
Enable FastStart for non-Avaya IP Phones
Default = Off
A fast connection procedure. Reduces the number of messages that need to be exchanged before an audio channel is created.
Fax Transport Support
Default = Off
This option is only supported on trunks with their Supplementary Services set to IP Office SCN or IP Office Small Community Network - Fallback. Fax relay is supported across H.323 multi-site network lines with Fax Transport Support selected. This will use 2 VCM channels in each of the systems. Fax relay is only supported on IP500 V2 systems with IP500 VCM, IP500 VCM V2 and or IP500 Combo cards. Fax relay is not supported on Server Edition Linux servers.
Local Tones
Default = Off
When selected, the tones are generated by the local system to which the phone is registered. This option should not be used with lines being used for a multi-site network.
DTMF Support
Default = Out of Band
DTMF tones can be sent to the remote end either as DTMF tones within the calls audio path (In Band) or a separate signals (Out of Band). Out of Band is recommended for compression modes such as G.729 and G.723 compression modes where DTMF in the voice stream could become distorted.  
Allow Direct Media Path
Default = On
This settings controls whether calls between IP endpoints and/or lines must go through the IP Office.
  • If disabled, calls go through the IP Office and use its resources. RTP relay allows calls between devices using the same audio codec to not require a voice compression channel.
  • If enabled, calls can take routes other than through the IP Office system. Both ends must support direct media and have matching VoIP settings. For example, both ends must use the same protocol (SIP or H.323), same addressing (IPv4 or IPv6), and so on. Otherwise, the call goes through the IP Office system.
    • For extensions, disabling Requires DTMF allows the extension to attempt direct media even if the other end has differing DTMF settings.
Progress Ends Overlap Send
Default = Off.
Some telephony equipment, primarily AT&T switches, over IP trunks send a H.323 Progress rather than H.323 Proceeding message to signal that they have recognized the digits sent in overlap state. By default the system expects an H.323 Proceeding message. This option is not available by default. If required, the value ProgressEndsOverlapSend must be entered into the Source Numbers tab of the NoUser user.
Default Name From Display IE
Default = Off.
When set, the Display IE is used as the default source for the name.
Related links
H.323 Line