Best Practice: A simple workaround is to first input the outgoing phone number before lifting the handset or initializing the speakerphone.
To set the Interdigit Short Timer in the phone's web interface
- Obtain the phone's IP address by pressing Menu > 10 Status > 2 Network Status.
- Open a web browser on a computer on the same network as the phone, and browse to the phone's IP address.
- Select Admin login and enter the phone username and password.
- Click Advanced to bring up all available options.
- Click the Regional tab.
- Scroll down to the Control Timer Values (sec) section.
- Update the Interdigit Short Timer with a higher value. This will determine how many seconds you have to dial before the phone gives a busy signal and the error.
- Scroll down and click Submit All Changes. The phone might reboot.
- After the phone has rebooted and come online, lift the receiver (or press the speakerphone button) to test if your timer settings have taken effect.