Webex Outbound Dialer

As of Q4 2021, it isn't possible to natively add a non-Webex registered SIP endpoint to a Webex Meeting ad-hoc. This proof of concept solves that issue!
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About The Project

Video Demo

Flow Diagram

Figure A:
I. 1 is the initialToken user who dials into the group meeting without any local media. This can be a guest user, bot, or licensed user.
II. 1 receives the remote stream from the group meeting, and passes it as the local stream for 2.
III. 2 is the endpointToken user who dials the SIP endpoint (interpreter service).

• endpointToken cannot be a guest token AND cannot be the same as initialToken.

IV. 2 receives the remote stream from the SIP endpoint and passes it as the local stream for 3.

• if provided, 3 will use the optional meetingToken, but otherwise uses the endpointToken.

V. 3 dials into the group meeting and receives another remote stream.

Figure B:
I. It was necessary for 3 to dial into the meeting, because 1's local media cannot be updated because it had no local media initially.

• This is a limitation of the SDK.
• This now creates a loop where the SIP device user can see and hear themself in the meeting.
  II. 2's local media can be updated, because it had initial media (provided by 1).

III. Therefore, 3 uses its remote stream to update the local stream of 2.

Figure C:
I. 1 is no longer needed, so it can be dropped, solving the loop problem, and creating the bridge.

Setup

Prerequisites & Dependencies:

Each of these is required:

• MacOS 10.15 (Catalina)
• node.js (>= v12.0)
• playwright
• express

Installation

1. Clone the repo

   git clone repo

2. Set Environment Variable PORT

   export PORT=12345 #(the port your server listener will expose)
   

   If you set PORT=12345 in a file named .env in the root directory, this variable will be loaded in server.js at runtime.
3. Install the packages.

   npm i -D playwright
   npm install dotenv
   npm install express
   

4. Start the server

   >$ node server.js 
   Your app is listening on port 12345
   

Usage

Once your server is running, you can test it with HTTPS POST requests with a JSON payload to the /bridge path. Example:

POST http://localhost:12345/bridge

JSON Data Parameters

Key	Required	Type	Description
initialToken	required	String	The Webex Account Bearer token for the 'operator' user that joins the meeting first. This can be a guest user.
endpointToken	required	String	The Webex Account Bearer token for the licensed user that places the outbound call to endpointSIP.
meetingToken	optional	String	The Webex Account Bearer token for the user that joins the meeting after the 'operator' has connected and after the endpointSIP call has been placed. If null or not provided, endpointToken will be used.
meeting	required	String	The sip address, meeting URL, or roomId of the main meeting to join.
endpointSIP	required	String	The sip address of the device to be added to the meeting.
wait	optional	Boolean	Defaults to false. If true, the POST request will not return immediately, but wait for e full bridge to be established before returning the result. Will wait for a max of about 1 minute. Example: if the 'operator' or endpoint user has to be let in to the meeting, and is let in quickly, the response will contain the result of the bridge setup. If the 'operator' or endpoint user are not let in to the meeting within 1 minute, the request will return with the last known state of the bridge setup. If false, null or not provided, the POST request will respond immediately with an acknowledgement, but the bridge setup result will not be known.

Sample:

{"initialToken":"MTM1NzlkMjUtOABCDEFGHIJKLMNOPQRSTUVWXYZ_AB12_abcdef-1234-1111-a1b2-abcdefghijk", "endpointToken":"ZWM3YmMzNzktOWYABCDEFGHIJKLMNOPQRSTUVWXYZ_CD34_zyxwvut-3456-4444-5555-10987654321", "meeting":"[email protected]", "endpointSIP":"[email protected]", "wait":true}

Postman Sample:

Serve

If you want to serve this at system startup, I recommend using pm2.

1. npm install -g pm2
   Note: You may run into an issue where pm2 throws an error when it tries to access a directory that does not exist. You can simply make the directory in that case. For example

   mkdir -p /Users/<username>/Library/LaunchAgents/  
   

2. pm2 startup
   Note: Follow the instructions from pm2 - run the command it provides to you.
3. Start the server with pm2

   pm2 start path/to/bridgeCall/server.js --watch
   

4. pm2 save
5. Unfortunately, this will only start the server once <username> logs into the mac. We want it to start at boot, so what I had to do was move the .plist file that was created in ~/Library/LaunchAgents and move it to the system root directory /Library/LaunchDaemons
   Note: this is not the Library directory that exists under the users directory i.e.

   cd /Users/<username>/Library/LaunchAgents/
   mv pm2.<username>.plist /Library/LaunchDaemons
   

6. I then also had to manually change the UserName in the .plist file to root:

   <key>UserName</key>
   <string>root</string>
   

License

All contents are licensed under the MIT license. Please see license for details.

Disclaimer

Everything included is for demo and Proof of Concept purposes only. Use of the site is solely at your own risk. This site may contain links to third party content, which we do not warrant, endorse, or assume liability for. These demos are for Cisco Webex usecases, but are not Official Cisco Webex Branded demos.

Contact

Please contact us at [email protected]