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Pedro Sanders for Fonoster Inc

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Building a VoIP Network with Routr on DigitalOcean Kubernetes: Part I

Building a VoIP Network with Routr on DigitalOcean Kubernetes: Part I

Routr v2 takes a radical design approach by being container-first and taking full advantage of environments like Kubernetes. In this three-part tutorial, you will learn how to:

  • Create a load balancer on DOKS and deploy Routr
  • Secure the admin and signaling ports with Let's Encrypt
  • Prepare the network for production

Before you continue, be sure to star Routr on GitHub 👇

GitHub logo fonoster / routr

⚡ The future of programmable SIP servers.

Requirements

Before you start this tutorial, you will need the following:

  • An account in DigitalOcean and a DOKS cluster
  • NodeJS >= 18 (Use nvm if possible)
  • Routr command-line tool (Install it with npm install -g @routr/ctl)
  • Kubectl with access to your DOKS cluster
  • Helm (Get from here https://helm.sh/)

Check the DOKS cluster and other dependencies

This tutorial assumes you have a running DOKS cluster. If you need help creating a DOKS creating, please visit the following link: https://docs.digitalocean.com/products/kubernetes/how-to/create-clusters/

With that, ensure you can connect to your cluster using Kubectl before continuing with the next steps.

Creating a new Load Balancer in Digital Ocean

To create a new load balancer, go to the networking section within the DigitalOcean panel, find the "Load Balancers" tab, and click "Create Load Balancer."

Your page will look like this:

Load Balancers Page

Follow the creation steps using all the default values and note the load balancer's name.

Installing Routr using Helm

Once your load balancer is up and running, follow the next instructions to install Routr with Helm.

First, add Routr to the Helm repository with:

helm repo add routr https://routr.io/charts
helm repo update
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You can get details about the new repo with the following:

helm repo list
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Then, create a namespace for Routr using the create namespace subcommand:

kubectl create namespace routr
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Next, create a values.yaml with the following content find, and remember to replace the externalAddrs property and serviceAnnotationsTCP with your values.

Filename: values.yaml

edgeport:
  externalAddrs: ["159.203.158.25"]
  serviceTypeTCP: LoadBalancer
  serviceAnnotationsTCP:
    service.beta.kubernetes.io/do-loadbalancer-name: "nyc1-load-balancer-01"
  transport:
    tcp:
      enabled: true
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Alternatively, you could use the annotation kubernetes.digitalocean.com/load-balancer-id to use the load balancer's ID instead of the name.

Finally, create the SIP network with:

helm install sipnet routr/routr-connect --namespace routr -f values.yaml
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Within a few minutes, you will see the following message:

Succesful deployment

You can check the status of the Pods with the "get pods" subcommand, like here:

kubectl get pods -n routr
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You should see a list of pods and their status. If the status of all services is "Running," you are ready to go.

PODs status

Please see the Official Chart for many more options for your deployment.

Configuring a Domain, Credentials, and Agents in Routr

With Routr deployed, the next step will be to create the following resources:

  • The "sip.local" domain
  • Two sets of credentials (e.g., 1001 and 1002)
  • Two SIP agents (e.g., John and Jane)

To send admin commands to Routr, you must expose the admin port.

Here, for simplicity, we will use port-forward to expose the admin port. However, you might use a different method in production, like creating a separate load balancer.

To open the admin port, first list the services of your deployment and find the one for your admin port with the following:

kubectl get services -n routr
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Then, open the admin using the port-forward subcommand:

kubectl port-forward svc/sipnet-routr-apiserver 51907 -n routr
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Once the port is open, on a separate screen, begin creating a Domain with:

rctl domains create --insecure --endpoint=localhost:51907
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Your output will look as follows:

Press ^C at any time to quit.
 ›   Warning: Egress rules unavailable due to 0 configured numbers.
? Friendly Name Local Domain
? SIP URI sip.local
? IP Access Control List None
? Ready? Yes
Creating Domain Local Domain... 3b20410a-3c80-4f66-b7b3-58f65ff65352
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In the next part of the series, I will go over securing the connection with a self-signed certificate or using certificates from Let's Encrypt.

Continue by creating two sets of credentials with the following command:

rctl credentials create --insecure --endpoint=localhost:51907
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Follow the prompt and repeat to create two sets (e.g., 1001 and 1002). Your output for the first credential will look like this:

This utility will help you create a new set of Credentials.
Press ^C at any time to quit.
? Friendly Name John Doe - Credentials
? Username 1001
? Password [hidden]
? Ready? Yes
Creating Credentials John Doe - Credentials... 5fbc7367-a59d-4555-9fc4-a15ff29c24c8
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Finally, create two sets of Agents:

rctl agents create --insecure --endpoint=localhost:51907
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The output for your first Agent will look like this:

This utility will help you create a new Agent.
Press ^C at any time to quit.
? Friendly Name John Doe
? Select a Domain sip.local
? Username 1001
? Credentials Name John Doe - Credentials
? Max Contacts
? Privacy None
? Enabled? Yes
? Ready? Yes
Creating Agent John Doe... 662a379d-66f1-4e6e-9df5-5126f1dcb930
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Please repeat the process for Jane.

Registering and Calling using Blink

Using Blink or your preferred softphone, create a new agent using the parameters in the abovementioned steps.

The result should show a green indicator like in the screenshot below.

Registering Blink

Repeat the process from another instance of Blink, and make a call going to the main screen and typing the extension.

Calling the extension 1002

You should be able to send and receive calls from both devices.

What's next

Thank you for making it this far. In the upcoming days, I will publish Part II of this series, which will go over securing the signaling path and the admin port. In the meantime, feel free to enjoy the following tutorials:

Top comments (1)

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prawee profile image
Prawee Wongsa

Smart deploy!