Ostel is a public testbed of the Open Secure Telephony Network (OSTN) project, with the goal of promoting the use of free, open protocols, standards and software, to power end-to-end secure voice communications on mobile devices, as well as with desktop computers. Other OSTN instances include Pillow Talk and formerly included Tanstagi and Intimi.ca. If you'd like to set up your own instance, please visit our cookbook

Visit Ostel.me to learn more about the Open Secure Telephony project and to sign up to become a test user.

OStel App Setup

Ostel recommends the latest nightly builds of the CSipSimple app to access the Ostel VOIP network on your Android phone. CSipSimple includes a wizard for setting up an account configuration for any server which complies with our Open Secure Telephony Network specification. The version in the Google Play store should now also support OSTN.

In short, this means calls made with your Ostel account in CSipSimple are fully encrypted.

Technically this means it uses TLS or SSL to secure the SIP signaling traffic, and supports proxying of the RTP media streams for the actual voice or video calls, without in any way interfering with the ZRTP encryption passing through it.

To download the app, use the QR Code above or go to the direct link below in your browser. The .apk will be downloaded and can be used to install the application.
<p style="text-align: right" class="p3"><span class="s1">Direct Link - Nightly: <span class="s2">http://nightlies.csipsimple.com/trunk/CSipSimple-latest-trunk.apk> Mutual Funds Australia

<p style="text-align: right" class="p3"><span class="s1">Direct Link - Official: <span class="s2">https://play.google.com/store/apps/details?id=com.csipsimple>

1. Now that CSipSimple app is installed, go to the applications folder and open CSipSimple.

2. You should see the "Easy Configuration" settings screen.

Read through these settings to choose when Ostel incoming and outgoing Ostel calls will be available (on 3G, wifi only, etc). Click Save to continue.

3. Next click the 'Add Account to continue to add your Ostel account.

4. You now should see a list titled "Choose Wizard" with a list of VOIP providers.

Scroll down in the list until you see OSTN then select it.

5. Now you are the account settings screen.

Click User name. Enter the user name we sent to you in the email (ex. 1001). Click OK to continue.

Click Password. Enter the password we sent to you in the email. Click OK to continue.

Click Server. Enter 'ostel.me' Click OK to continue.

Click Save to continue.

6. You should see it read "Registering" for a few seconds until the bar to the left of your account name turns Green and reads Registered.

Congratulations! You've successfully signed in.


Test Your SIP Connection

From the dial pad, dial 9-1-9-6 then click the green receiver icon at the bottom. Speak into the microphone. You should hear yourself. If so, you have successfully completed the echo test and your client should be fully functional. Way to go. You're on your way to being an elite user.

Listen to music

This feature is not currently functional. From the dial pad, dial 9-6-6-4 then click the green receiver icon at the bottom. You will hear Girl Talk's album "All Day" looping all day, every day. Play the whole album over your mobile internet connection and [mailto: let us know] if you've had any connectivity issues. Party on, you're well on your way to being an elite user. And if you like the album, you can get it on the Illegal Art site.

Place a Call

From the dial pad, dial 1-0-0-3 then click the green receiver icon at the bottom. You will be connected to a user (if they are not in a meeting). A 4 character alphanumeric ZRTP password will be displayed on your homescreen. The user will ask you to verify the password. Once both users confirm that the password is the same, you are now having an encrypted conversation. Tell this user what you're most looking forward to using encrpyted voice chat for, add a feature request, or tell a joke. After all, it's just between you and that user. Congrats on being elite!


Error while registering - Forbidden. What happened?

Please check that there are no extraneous spaces in any of the fields you were meant to alter. Check that all spelling is using lowercase. Make sure that all brackets (<>) are properly set.

I changed my settings but I'm getting the same error.

Try to exit the application and restart it. Click "Back" until you read the dial pad. Click "Settings" to reveal the options Menu. Click "Disconnect" to exit the app completely. Launch the app again from the applications folder and it will reboot and try to connect using the new settings you entered.

My connection is now inactive. What happened?

<span class="s3">Has the connection been over your 3G/4G connection. Perhaps the</span> provider is blocking our SIP ports. Please try wifi. If this happens repeatedly, please notify us and we will look into it.

I'm running Cyanogen. Why isn't Ostel working?

Good question. It should. But it doesn't right now. We're looking into this. Hopefully it will be fixed soon.

Can someone record my phone calls?

Not even us pros at Guardian can your calls if you've encrypted them with ZRTP. Noone else can either.

Are you logging any data?

While we're in the Alpha testing phase we have to log some data in order to best develop and test the tool. We do our best to log this data securely and with privacy considerations in mind. Our call records and user records are kept separate so that even with the logs it is not possible to track who has been speaking with whom.

I'm running Orbot. Why isn't Ostel working?

Unfortunately, VOIP communication doesn't work over a Tor connection. Please turn off Orbot when running OStel.

My phone won't allow me to install the Ostel App.

Have you enabled your phone to install apps from 3rd parties? Go to Settings then click on Applications. Under Unknown sources, make sure that the box is checked, allowing the installation of non-Market applications.

What are the technical details on Ostel?

So glad you asked! Check out the full details about our software and hardware on https://guardianproject.info/wiki/OSTN

My problems aren't listed here. Can I get in touch with someone?

We're always happy to help! [mailto: Send us an email] and we'll help troubleshoot your issue.

How can I get my friends involved?

Alpha testing is more fun when doing it with friends. We're always looking for smart and passionate people. They can sign up at <span class="s4">https://ostel.me/> or follow us on Twitter <span class="s4">https://twitter.com/#!/guardianproject> or on our Blog <span class="s4">https://guardianproject.info/blog/> to find our when they can become a tester too!

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