Configuring the H.323 protocol

Last Updated : Jun 18, 2025 |

About this task

Enable the H.323 protocol and configure the related settings to call inbound and outbound phone numbers. You can also enable and configure the H.239 protocol for dual video streaming and manage the Dual Tone Multi-Frequency (DTMF) options.

Procedure

  1. On the Settings menu, go to Protocol > H.323.
  2. To call other devices using their IP address when your H.323 account is registered on the domain, select the Enable Call IP Address Directly When Registered check box.
  3. To enable H.245 tunneling, select the Enable H.245 Tunnel check box.
  4. To obtain a gatekeeper and send a gatekeeper request, select the Send GRQ check box.
  5. To enable the H.239 protocol extension for parallel video streaming, select the Enable H.239 Control check box.
  6. To enable static dual streaming with H.239, select the Enable H.239 Static Dual Stream check box.

    If the check box is selected, during an H.323 call, the secondary video stream channel is open on the firewall to interact with certain multipoint control units (MCUs).

  7. For the Send DTMF As setting, select one of the following options:
    • RFC2833: To transmit DTMF tones separately from the audio stream in Real-Time Protocol (RTP) packets.

    • Q.931: To transmit DTMF tones using the Q.931 protocol.

    • In Band: To transmit DTMF tones as part of the regular audio stream.

    • String: To transmit DTMF tones as a string.

    • Audio Frequency: To transmit DTMF tones as an audio frequency.

    You use the DTMF interface to perform certain actions during a call.

  8. Click Save.