Lifeline - 2-Way Audio

Enabling two-way audio to hear and speak into your rooms with Lifeline

Written By Daniel Gleaves

Last updated About 1 month ago

Before You Start: What You'll Need

Required hardware for each room:

  • A GrandStream GSC3516 ceiling speaker (available on Amazon) β€” this is the speaker that mounts in the ceiling of the escape room

  • An Ethernet cable running from the speaker to your network switch

  • A PoE (Power over Ethernet) switch or PoE injector β€” this powers the speaker through the Ethernet cable so you don't need a separate power outlet

Required hardware at each Game Master station:

Important: You must access Drawbridge using your venue's web address (e.g., yourvenuename.drawbridgeai.app), not the IP address (the number like 192.168.0.2). Lifeline will not work if you're using the IP address.


How to Use Lifeline (Day-to-Day)

Once everything is set up, using Lifeline is simple. On the Game Master page for any room, look for these icons in the Player Toolbar:

Icon

What it does

πŸ‘‚ Ear icon

Click to start listening to the room

🎀 Microphone icon

Press and hold to speak into the room. Release to stop.

πŸ”΄ Red ear with slash

Click to stop listening and hang up

Important: You must click the ear icon first before the microphone icon appears. And you have to hold the microphone button β€” just clicking it won't work.

Only one Game Master station can listen to a room at a time. If someone else already has the ear active for that room, yours won't connect until they hang up.


Setting Up Lifeline for the First Time

There are three parts to setting up Lifeline. If this feels overwhelming, you're welcome to contact support@drawbridgesolutions.com, and the Drawbridge team can remote in and walk you through it.

Part 1: Setting Up Each Ceiling Speaker

You'll repeat these steps for every GrandStream speaker you install.

  1. Plug the speaker into your PoE network switch using an Ethernet cable

  2. Find the MAC address printed on the back of the speaker β€” it looks like this: C0:A7:14:E3:20:B2

  3. In a browser on any computer on the same network, go to: https://gsc_ + the MAC address with no colons + .local Example: If the MAC address is C0:A7:14:E3:20:B2, you'd go to: https://gsc_c0a714e320b2.local

  4. Log in with username: admin and the password printed on the back of the speaker

  5. Change the admin password (important for security):

    • Go to System Settings > Security Settings

    • Enter the current password, then set a new one that's easier to remember

    • Save it somewhere safe and share it with Drawbridge support if needed

    • Click Save and Apply

  6. Click the Accounts tab, then click Accounts

  7. Under General Settings, fill in the following:

    • Check Account Active

    • SIP Server = the IP address of Drawbridge machine

    • SIP User ID = pick a 3-digit number for this speaker (e.g., 101, 102, 103 β€” do not use 301)

    • SIP Authentication ID = same as SIP User ID (each speaker must be different)

    • SIP Authentication Password = valcoms

    • Leave everything else as default

    • Click Save

  8. Under Call Settings: uncheck "Play Warning Tone for Auto Answer Intercom"

  9. Under Advanced Settings: make sure everything is unchecked. Click Save

  10. Click the Calls tab, then click the Greylist tab:

    • Set Greylist Calls to Auto Answer

    • Click Save

  11. Click the Phone Settings tab, then Call Settings:

    • Uncheck "Enable Call Waiting"

    • Uncheck "Enable Call Waiting Tone"

    • Set Automatic Answer Ringing Time (s) to 0

    • Click Save

  12. Click the Network Settings tab, then Ethernet Settings:

  1. Internet Protocol = IPv4 Only

  2. Uncheck Different Networks for Data and VoIP calls

  3. IPv4 Address Type = Static

  4. IPv4 Address, Subnet Mask, Gateway will be assigned by you, according to your network configuration

  5. Click Save


2. FreePBX Configuration

Once each speaker has been configured, you'll need to add each to FreePBX

  1. Navigate to <DrawbridgeIP>:3002

  2. Login with username: admin, password: admin

  3. Click on Settings at the top

    1. Change HTTP Bind Address to 0.0.0.0

  4. In the top left, hover over the Applications Tab

    1. Click Extensions

  5. Click Add Extension

    1. Click add new SIP [chan_pjsip] Extension

  6. In the General Tab

    1. User Extension = SIP User ID from Part 1, do not use 301

    2. Secret = valcoms

    3. User Password = valcoms

    4. Click Save

  7. Repeat 6 for each of your speakers

  8. Create one more extension

    1. User extension = 301

    2. Secret = valcoms

    3. Click the Advanced Tab

      1. Enable AVPF = Yes

      2. Enable ICE Support = Yes

      3. Enable rtcp Mux = Yes

      4. Media Encryption = DTLS-SRTP

      5. Allow Non-Encrypted Media (Opportunistic SRTP) = Yes

    4. This is the Drawbridge Extension, allowing you to listen in to the rooms


3. Adding Speakers to Drawbridge

The speakers can now be added to Drawbridge.

  1. Go to Settings

  2. Click the game you want to add a speaker to

  3. Click the Speakers Tab

    1. Click Add New Speaker

    2. Name the speaker and add the Extension number from Part 2

    3. Click Save

  4. Navigate to the Gamemaster page for the game you added the speaker to

  5. In the Player Toolbar, between Custom Hint and Alert Hosts, you should now see the name of the speaker and an ear

  6. Click the ear to list into the room

    1. The speaker is now marked as busy, only one gamemaster station is able to listen into a room at a time

    2. Click and hold the microphone with a slash to begin speaking into the room, release to stop talking into the room

    3. Click the red ear with a slash to stop listening to the room

  7. Repeat step 4 for every speaker


πŸ› οΈ Troubleshooting

("Our microphones stopped working on all stations overnight β€” nothing changed")

This is the most common support scenario, and it's almost always one of these three things:

1. Browser blocked the microphone (most likely)

Browsers occasionally reset microphone permissions after an update or computer restart.

Fix it on each station:

  • Open Drawbridge in Chrome

  • Look in the address bar for a πŸ”’ lock icon or a microphone icon β€” click it

  • Make sure the microphone access says Allow

  • Reload the page and test

You can also check browser permissions directly:

  • In Chrome, go to Settings > Privacy and Security > Site Settings > Microphone

  • Make sure your Drawbridge address is listed under Allowed

2. You're accessing Drawbridge via IP address instead of your venue URL

Lifeline only works when you access Drawbridge through your venue's web address (e.g., yourvenuename.drawbridgeai.app).

Check the address bar on each station. If it shows a number like 192.168.1.5, that's the IP address. Change it to your venue's .drawbridgeai.app URL.

3. Another station already has the room checked out

Only one Game Master can listen to a room at a time. If another station has the ear icon active, all other stations will be blocked from connecting.

Ask your team to check if any other station has a room open and click the red ear-with-slash icon to hang up.

"The microphone icon isn't showing up."

You need to click the ear icon first. The microphone icon only appears after you've started listening.

"I can hear the room, but players can't hear me."

Make sure you're pressing and holding the microphone button. Just clicking it won't transmit it's designed to work like a walkie-talkie push-to-talk button.

"Only one room's audio stopped working; others are fine."

This is likely specific to that room's ceiling speaker rather than Drawbridge itself. Work through this checklist in order:

1. Go into the room and check the ceiling speaker β€” is the Ethernet cable firmly plugged in at both ends?

2. Follow the cable to your network switch β€” is it plugged into a PoE port? (Some switches only have PoE on certain ports, often labeled "PoE" or with a lightning bolt icon)

3. Unplug the Ethernet cable from the speaker, wait 10 seconds, and plug it back in to force a restart

4. Wait about 60 seconds, then test the audio again in Drawbridge

If you've already tried resetting through Settings > Lifeline and tested multiple Drawbridge windows or browsers:

The issue is almost certainly the physical speaker in that room, not Drawbridge. The speaker may need to be re-registered with your system. At this point, contact Drawbridge support and let them know:
- Which room is affected (e.g., "Mansion Murder 2")
- That you've already reset Lifeline through Settings and tried multiple browser instances
- That the other rooms are working fine

This gives them everything they need to remote in and fix the speaker registration quickly without back-and-forth.

"The microphone works on some computers but not others."

  • Make sure the USB microphone is plugged directly into the computer, not through a USB hub

  • Go to the computer's Sound Settings and confirm the USB microphone is selected as the input device (a restart can sometimes switch it back to a built-in mic)

  • Check that the microphone isn't muted in Windows sound settings

"None of the above worked"

Contact Drawbridge support β€” they can remote in and check your FreePBX configuration, which can sometimes get out of sync after server restarts.

support@drawbridgesolutions.com