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Inviting a H.323/SIP room system to a meeting Follow


The H.323/SIP Room Connector call-out feature allows you to dial out to an H.323 or SIP room system from the Zoom Client using the public IP address or SIP URI assigned to the device.

This article covers:


  • Host account is Pro or above
  • At least one Room Connector port subscription (a device connected via call-out will count as one port)
  • Device must have an external, public IP address or SIP URI
  • External calls to the device must be allowed on your network firewall
  • Zoom version 3.5 or higher is required to use the call-out feature. 

Inviting a H.323/SIP room system

  1. Sign in to the Zoom Desktop Client.
  2. Start or join a meeting.
  3. Click Manage Participants (if you're the host) or Participants in the meeting controls.
  4. Click Invite at the bottom of the participants panel.
  5. Click the Invite a Room System tab.
  6. Select the Call Out tab
  7. Enter the IP address or SIP URI of the H.323 or SIP device, or select a device from the H.323/SIP Rooms Directory
  8. Select the type of call you would wish to make - H.323 or SIP
  9. Press Call

  10. Click Show Keypad if you need to enter digits (e.g. meeting ID) during the call-out.
  11. Enter numbers using the pop-up keypad.

Setting the call speed for call-out to H.323 devices

The default call-out speed is 1920kbps (maximum). To set the call speed when using the Zoom call-out feature, you can enter the speed in to the dial string as seen in the below examples.

[IP address];speed=768k

[IP address];speed=768000

[IP address]##[E.164 address];speed=1472k

Sending DTMF tones in call-out to H.323 devices

To send DTMF tones when connecting to a Gatekeeper, MCU, or other H.323/SIP hardware that requires a party number, conference number, or e.164 address, you can enter these in the Call-out dial string.

[IP address];dtmf=[DTMF tones]

  • DTMF tones have a 1 second interval
  • Entering a "," will pause 1 second in between DTMF tones

For example:

Device IP address:
Conference Number: 15562
Password: 622


  • Dials IP address
  • Send DTMF tones '1' '5' '5' '6' '2' '#' pause pause '6' '2' '2' '#'

To add a call speed along with DTMF tones (using the example above):

Desired Call-Speed: 768 kbps


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