Get to know your Grandstream phone

Put a call on Hold: During a call, press the Hold button or the Hold soft key. The caller will be put on hold (they may hear hold music or tone). To resume the call, press the flashing Line key or the ReSum soft key.

Transfer a call: There are two ways to transfer:
1. Blind Transfer (unannounced): Press the Transfer key or soft key, then dial the extension/number. Immediately press the BlindTrnf soft key to send the call away without announcing it. You can hang up once you see the call transferring.

2. Attended Transfer (announce first): Press Transfer, dial the extension/number and wait for the person to answer. Talk to them first, then press Transfer again (or AttTrnf soft key) to complete the transfer. If they can’t take the call, you can cancel the transfer (press Cancel or the flashing line key to return to the original call).

3-way Conference Call: While on a call, press the Conference key or Conf soft key. Dial the second person’s number and wait for them to answer. Then press the ConfCall soft key to join all parties together into a 3-way call. If you need to drop the new person, press Cancel before completing the conference, or use the on-screen option to Split or Kick a party if supported.

Speakerphone: Press the Speaker button to toggle hands-free mode on or off. The button will light up when speakerphone is active. Speak toward the phone (make sure you’re close enough for the microphone to pick up your voice clearly) and you’ll hear the other person through the phone’s speaker.

Headset: Plug a compatible wired headset into the RJ9 Headset port on the back of the phone. Then press the Headset button (with a headset icon) to activate headset mode. When the headset light is on, calls will go to your headset. Pressing the Headset button again will hang up or switch off the headset.

Adjusting Volume: During any call – whether on handset, speaker, or headset – press the Volume + or – keys to increase/decrease the sound volume. You can do this while hearing dial tone, during the call, or for the ringer when idle.

Mute: To mute yourself on a call (handset, speaker, or headset), press the Mute button (often a microphone icon with a slash). The button usually lights up red when muted. You can hear the other side, but they cannot hear you. Press Mute again to unmute.

Voicemail (Message) Button: Press the MESSAGE button (envelope icon) to dial your voicemail access number. The first time you access voicemail, you might need to enter a PIN (which your provider should have given you) and set up your greeting. The phone’s Message Waiting Indicator (MWI) light will blink green to indicate new voicemails. After you listen to all new messages, the light will stop blinking (it may take a minute to update).

*If pressing the button doesn’t reach your voicemail, your phone may not have a voicemail number stored. In that case, dial the voicemail number provided by your service (often an extension like *97, 98, or a full phone number) and follow the prompts.

Voicemail on multiple lines: If your phone has more than one line (SIP account) configured, the MESSAGE button may prompt you to choose which line’s voicemail to access. Use the arrow keys to select the line, then press OK or the line key. The phone might also show a small envelope icon next to any line that has new messages.

Your phone  might be updating firmware or struggling with a configuration download.

• Give it time: If you see messages like “updating” or “provisioning,” wait a few minutes. Sometimes large updates take several minutes.
  
  
• Power cycle: Unplug the power (or network PoE cable), wait 10 seconds, and plug it back in. This can clear a temporary glitch.
  
  
• If it still doesn’t start properly (for example, it reboots over and over), contact support. There may be a configuration issue. They might advise doing a factory reset (which you shouldn’t do unless instructed, since it will wipe settings) .
   

The phone isn’t connected to the VoIP service. This could be a network issue or account configuration issue.

• Network check: Ensure the Ethernet cable is connected and your internet is working. If your computer is connected through the phone, see if you can go online. If not, the network might be down.
  
  
• Reboot devices: Restart your modem/router, then reboot the phone. Networking gear may need a reset.
  
  
• Time/Date check: If the phone’s clock is way off (and says Not Registered), it’s a clue it didn’t get network time. That often points to no network connection. Double-check the cables and network.
  
  

If the network is fine, the service account might not be configured. We can check if the phone is provisioned in our system. We may ask for the phone’s MAC address (on the bottom label) to ensure it’s added. Contact us.

This is usually a network or headset issue. It could be a firewall blocking voice traffic, or using a headset with a faulty microphone.

• Check volume & mute: Make sure neither end is muted. Press the Volume up button during the call. If you’re using a headset, try using the handset or speakerphone to see if the audio returns – the headset might be the issue.
  
  
• Network (for tech-savvy users): If this phone is used at home behind a router, sometimes specific firewall settings can block voice audio (SIP ALG issues). You might try disabling SIP ALG on your router (if you know how), or contact your provider – they can often detect one-way audio and advise on router settings.
  
  
• Restart call: Hang up and call again – sometimes one-way audio is a fluke with the connection.

If consistently one-way, contact us. It could be a NAT traversal issue that they need to adjust on their side or guide you to adjust on your router.

Choppy or robotic sound usually means network packet loss or low bandwidth. Echo can happen if the volume is too high or due to network latency.

• Local network: If on Wi-Fi or others are streaming, the call quality can suffer. If possible, use a wired connection (which you are, via Ethernet). Pause or limit big downloads during calls.
  
  
• Quality of Service (QoS): If you’re in an office, inform IT – they might need to prioritize voice traffic. At home, check if your router has a QoS setting for VoIP.
  
  
• Volume: Lower the volume a bit if the other person hears echo of themselves (your microphone might be picking up the speaker output).
  
  
• Test another call: Sometimes the internet path was just bad for that call. If the next call is fine, it was likely a transient network issue. Persistent issues should be raised to support – they can run diagnostics (ping, packet capture) remotely via GDMS to pinpoint problems.
  

The phone thinks there are unheard voicemails (or isn’t getting updates about them).

• Check if you indeed have new messages: dial the voicemail and listen to any new ones. After that, hang up and see if the light goes out after a minute.
  
  
• If the light is still on but no messages exist, you can try to refresh by rebooting the phone (power cycle).
  
  
• In rare cases, the message waiting indicator may get out of sync. Your provider can send a “reset” or re-synchronization command to your phone. If the light annoys you, they can also disable/enable the MWI subscription to reset it.

Do Not Disturb (DND) might be on, which silences ringing. Or the ringer volume might be at zero.

• Look at the screen when you expect a call. If you see a bell with a slash or “DND”, then Do Not Disturb is enabled. To toggle DND off, find the DND soft key (often on the idle screen) or via Menu → Do Not Disturb and disable it.
  
  
• If DND isn’t on, try pressing the Volume up button while idle to increase the ringer volume. The phone’s screen should show the volume level. Make sure it’s not all the way down (muted).
  
  
• Ensure the phone is not in Night mode or Call Forward All by mistake (some systems use star codes or softkeys for that).

Typically, the phone gets time from the internet (NTP server). If it’s wrong, maybe the time zone or network is not set correctly.

• Check the time zone: Press Menu -> Settings -> Time/Date and ensure the correct time zone is selected for your area. Adjust it if necessary (or choose to sync with DHCP or manual NTP server if you know those settings).
  
  
• If the time is wrong by exactly whole hours, it’s almost certainly the time zone setting. If it’s off by a random amount, the phone might not be reaching the time server – check your network connectivity.
  
  
• After adjusting, reboot the phone to see if it pulls the correct time.
   

• On the idle screen, simply press and hold the UP arrow (▲) for about 3 seconds. A Status Page will pop up showing the IP address and other info.
  
  
• Alternatively, go to Menu → Status → Network Status on the phone’s screen; the IP address will be listed there.

You generally won’t need this unless a technician asks for it, or if you’re logging into the phone’s web interface.
 

This could be caused by a temporary software glitch.

• Try a reboot (power cycle). This often clears any unresponsive behavior.
  
  
• If the screen is frozen, you can also reboot by unplugging the power (PoE cable or adapter), waiting a few seconds, and plugging it back in.
  
  
• In the rare case the phone becomes unresponsive often, note what you were doing when it happens and report it – firmware updates might be needed.