Simon Anderson

Sun, 16 Jan 2022 14:21:02 +1300 last edited: Sun, 16 Jan 2022 17:58:00 +1300

simon@littlefluffycloud.net

Starlink utilises CG-NAT to deliver service so a direct connection to a Starlink node from elsewhere on the Internet isn't possible. A solution is to establish an outbound VPN connection from the Starlink node, and subsequently route inbound traffic to Starlink across the established VPN link.

Why do this? In my particular use-case Starlink is deployed at a remote holiday home I want to monitor and manage whilst I'm not there.

There are any number of ways a VPN can be implemented. In this solution OpenVPN is used to establish a connection from a Raspberry Pi at the Starlink node to a Redhat Enterprise Linux Server elsewhere on the Internet, as depicted in the diagram below. OpenVPN is supported by a variety of platforms so my choice of Raspberry Pi and Redhat is immaterial: the configs presented here should work on any platform.

The network topology in this example is depicted below. We're going to establish a network-to-network VPN between the network 192.168.0/24 behind the Server, and the network 192.168.1/24 behind the Raspberry Pi Client. In order for this to work the Server requires an IP address which is connectable on UDP port 1194.

First we need to generate a secret key. We do so with the command:

openvpn --genkey --secret static.key

The resulting file needs to be deployed to the Raspberry Pi and the Server, on both platforms the default location is /etc/openvpn/static.key
Next we configure the Server to accept VPN connections. Edit the configuration file /etc/openvpn/server/server.conf to contain these values:
```
dev tun
proto udp4
ifconfig 10.0.0.1 10.0.0.2
route 192.168.1.0 255.255.255.0
keepalive 10 60
secret /etc/openvpn/static.key
cipher AES-256-CBC
```
Start the OpenVPN service with the following command so we can see errors and connections in the console:

openvpn --config /etc/openvpn/server/server.conf
Now it's time to configure the Raspberry Pi Client. Edit the configuration file /etc/openvpn/client/client.conf to contain the following values, remembering to include the public IP address of the server:
```
remote <remote IP Address of Server>    
proto udp4
dev tun
ifconfig 10.0.0.2 10.0.0.1
route 192.168.0.0 255.255.255.0
secret /etc/openvpn/static.key
persist-tun 
persist-key 
keepalive 2 10
cipher AES-256-CBC
resolv-retry infinite
```
Start the OpenVPN service on the Client with the following command. We should see the VPN tunnel established in both consoles:

openvpn --config /etc/openvpn/server/server.conf

Check to ensure the connection is operating properly with ping:

ping 10.0.0.2 -from the Server.
ping 10.0.0.1 -from the Client.

If ping doesn't work, check our firewall settings to ensure traffic is allowed across the VPN tunnel, which is probably device tun0.
At this juncture a VPN connection has been established between the Client and the Server. Now we need to enable routing between the two networks. On both servers issue the command:

/bin/echo "1" > /proc/sys/net/ipv4/ip_forward to enable IP forwarding. On both systems append the same command to the file /etc.rc.local so that forwarding persists across system restarts.
Finally we need to enable routing between the networks. On the Server side, publish a route to 192.168.1/24 with the internal IP address of the Server as the gateway. On the Client side publish a route to 192.168.0/24 with the internal IP address of the Raspberry Pi Client as the gateway.

Test everything is working with ping between systems on either side of the VPN. Enable the OpenVPN service on both systems so it persists across restarts and we're done: whenever Starlink is connected to the Internet the Raspberry Pi will establish a VPN connection to the Server, and re-establish it if it drops out.

Starlink Raspberry Pi Technology

Starlink WiFi Calling

Wed, 24 Nov 2021 20:53:09 +1300 last edited: Wed, 24 Nov 2021 22:34:22 +1300

Simon Anderson

simon@littlefluffycloud.net

The following post describes a method for routing phone calls and text messages (SMS) across Starlink, in the absence of an available cellular network. It is specific to the New Zealand context but the concepts described herein can be extrapolated to other countries.

The disadvantage of the Starlink service is it provides a data connection for Internet access but not cellular access for initiating and receiving phone calls and text messages (SMS) with a cellphone. This deficiency inhibits uptake amongst rural users who are prepared to forgo better speeds, greater reliability and lower cost in return for the facility to use their mobile phones.

Fortunately the distinction between Starlink and cellular isn't a zero-sum either or equation, or not necessarily: in the absence of a connection to the cellular network it is possible to use your mobile phone for calls and messages over Starlink. You'll still need to pay for an account with a mobile operator but you can route calls and messages across Starlink even when you're out-of-range of your operator's cellular network.

To do this you'll need to utilise the WiFi Calling feature on your phone. Turning this setting ON will instruct your cellular provider to route calls and messages to and from your phone across any available data network instead of the cellular network, if you are out-of-range of the latter.

There are two major constraints with this:

WiFi Calling is a feature of recently released cellphones, many older phones don't have it.
Cellular providers choose which phones can utilise this feature on their networks.

The second is a showstopper. Because cellular operators are bloody-minded, it won't matter how snazzy your new phone is. If your cellular provider doesn't sell that particular model themselves it will be impossible to convince them to enable WiFi Calling for it, even though their network and your phone both support WiFi Calling and it would be a trivial change for them to enable it.

Here's an example. These are two screenshots from a Samsung Galaxy J2 Pro I inherited from my nephew when he upgraded his phone. On the left is a screenshot of the WiFi Calling enabled when the phone has my 2Degrees SIM in it, on the right WiFi Calling is absent when the Spark SIM it originally came with is inserted. This is because 2Degrees supports WiFi Calling on this model cellphone but Spark doesn't.

Here are the lists of devices supported for WiFi Calling by the three major cellular operators in New Zealand: 2Degrees, Vodafone, Spark.

If the cellphone you own doesn't appear in the list of your operator's supported devices, my advice is to switch operator to one in which it does. Alternatively, purchase the cheapest model supporting WiFi Calling available and swap the SIM between it when you have to use it -at home in range of Starlink- and your snazzy phone when you're in range of the cellular network.

-SRA. Auckland, 24/xi 2021.

FB: https://www.facebook.com/simon.anderson.923/posts/10159421798870482
LI: https://www.linkedin.com/posts/simon-anderson-8736191_starlink-wifi-calling-activity-6869204628492431360-BbKf

Starlink technology

Starlink

Mon, 08 Nov 2021 17:37:38 +1300 last edited: Mon, 08 Nov 2021 17:50:43 +1300

Simon Anderson

simon@littlefluffycloud.net

This is Starlink deployed at the bach over the weekend.

Performance is so good, I was able to videoconference with my folks from here in Auckland and they gave me a guided tour of the gardens. This might not sound too impressive but being able to realtime videoconference over a satellite link via a groundstation in Sydney is astonishing bandwidth and latency.

Two other Tesla initiatives are interesting. The first is the purchase of Swarm, who make available LoraWAN from satellites for the princely sum of $5/month. Tesla intends to deploy this tech onto their Starlink satellites, so IoT devices can connect directly to them.

I already have a private LoRaWAN solution in place so this is less interesting for me personally, but professionally the ramifications of IoT sensors and actuators in remote locations are exciting.

The second initiative is the rumoured launch of the Tesla Model Pi smartphone which works with Starlink i.e., a satellite phone.

The potential for this tech to disrupt the local telecommunications market is massive. You will have seen those cheesy advertisements from Vodafone and Spark that say stuff like "coverage of 90% of where Kiwis live, work and play" which is marketing-speak for "about 60% coverage of the geographical area."

SpaceX's Starlink network already has 100% coverage of NZ. Adding a cellular capability is going to be extremely attractive to rural communities, and organisations requiring applications such as "man down" in remote locations.

I consider Elon Musk a bit of a charlatan, pushing vapourware, vastly exaggerating capability and time-to-delivery. It's fair to say most of the stuff he tries ends up on the scrapheap. Starlink is very much the exception. For a $NZ900 investment in hardware and a $NZ159/month service charge, we're pretty bloody ecstatic with the quality of the Starlink service and the potential of these ancillary IoT and cellular functions.

FB: https://www.facebook.com/simon.anderson.923/posts/10159361006660482

Technology Starlink

Nextcloud

Sat, 06 Nov 2021 14:33:25 +1300 last edited: Mon, 08 Nov 2021 17:49:57 +1300

Simon Anderson

simon@littlefluffycloud.net

Nextcloud is a private cloud solution. I've been using it (and its predecessor, Owncloud) for a decade.

I started using it initially as an alternative to corporate cloud offerings because it was open source, I could host it myself and most of all, it kept my data private. Over time I've watched it evolve into a genuine competitor for commercial services like Microsoft's Office 365 and Google Apps -and it's free.

In this article I'll describe Nextcloud, the features I use and the applications I integrate it with. The focus will be the apps I use to get the most out of Nextcloud. Others use Nextcloud differently: an advantage of the platform is that it is extremely flexible, allowing users to concoct their own recipes from the smorgasbord of options to suit their particular needs.

Conceptually, Nextcloud is a central repository which stores my data. It has a variety of applications to collect, process and present that data, and integrates with applications on my devices to collect, present and synchronise it. Crucially, the Nextcloud applications are to varying degrees, integrated with one another. Here are some of the features I utilise:

File storage, backup, synchronisation and sharing.
Contact, Calendar & Task management and synchronisation.
Location tracking.
Video conferencing and messaging.
News aggregation.
Time tracking.
Note taking and diary management.
Kanban and GANTT project management.

Listed here these features don't seem like much but together they comprise the majority of tools I use to manage my life. Some of these features I utilise by accessing the web interface of my Nextcloud instance, others are integrated into my operating system, applications, and my phone and tablet. The result is it doesn't matter where I am or which device I happen to be using, all of my data is accessible and presented to me when I need to know about it. Below is a list of the specific technologies I use to make this true:

Desktop

Nextcloud integrates directly with the GNOME desktop. Notifications appear in the system tray and transfers occur automatically via the file manager. The equivalent functionality exists for Microsoft Windows 10, and Apple MacOS.

Thunderbird is my personal e-mail client of choice. It integrates with Nextcloud for calendaring, tasks and contacts.

CalDAVSync is a plugin for Microsoft Outlook, the email client I'm almost always forced to use for work. This plugin allows me to synchronise tasks, calendar and contacts to my Nextcloud instance.

Phone

The Nextcloud app on Android or iOS is the essential component. It manages authentication to my Nextcloud instance for ancillary apps, synchronises files and backs up photographs.

DAVx utilises the WebDAV protocol to synchronise contacts, calendar events and tasks between my phone and my Nextcloud instance.

SMS Backup+ copies my SMS messages and call logs to my IMAP e-email account, and populates my Nextcloud calendar with call log event entries.

OpenTasks notifies my phone of "To Do" items in various task, calendar and project management Nextcloud applications.

Joplin is a diary application, similar to Microsoft's OneNote. I run this on my desktop as well, and Nextcloud synchronises my diary amongst my devices.

PhoneTrack tracks my location. And the Nextcloud app supports geofences and proximity alerts.

Nextcloud Deck is a Kanban-style lean project management methodology. It's designed for teams but I use it to track my personal activities.

Nextcloud Talk is the WebRTC client for private, encrypted, video-conferencing and messaging.

Nextcloud Timemanager tracks my time against clients and activities. It produces graphical insights and reports, useful when it comes to client invoicing.

Nextcloud News is an RSS/Atom feed aggregator. Most of the news and technology sites I visit regularly present their articles as feeds and this app collates them all.

Nextcloud Notes is a synchronised note-taking tool. Handy but pretty much superceded by Joplin for my use case.

I know this seems like a lot of apps but many of them operate wholly or mostly in the background, it really is a case of "set and forget." With this suite of apps in place I know my data is centralised and synchronised, readily accessible and presented to me when I need to know about it. For me, Nextcloud is ultimately convenient. It doesn't matter where I am or what device I'm using, my data is readily to hand and I have the tools to manage it.

Above all, I am in absolute control of my data. Nextcloud enables me to check out of the surveillance capitalism business model operated by Big Tech.

-SRA. Auckland, 6/xi 2021.

LI: https://www.linkedin.com/posts/simon-anderson-8736191_nextcloud-activity-6862576674941345792-aCRs

Technology Nextcloud

Starlink

Thu, 29 Jul 2021 22:09:47 +1200 last edited: Wed, 18 Aug 2021 22:05:40 +1200

Simon Anderson

simon@littlefluffycloud.net

I've had a technology problem I've been unable to solve for almost a decade.

Our family holiday home is in an extremely remote location, an island to be precise, off the coast of New Zealand's South Island. The property is completely off-grid as there is absolutely no infrastructure whatsoever.

The challenge -in which I have singularly failed- is to establish a persistent Internet connection and until now, the only viable option has been cellular. By precisely tuning a 24dBi antenna by hand to point at a rock at the top of the range opposite our place I can obtain just a slither of cellular connectivity from the mainland. Like this:

Which is good enough when I'm in residence but not enough to establish a stable connection when I'm not. To resolve this I've tried numerous amplifiers and different combinations of antennas, to achieve the outcome described here. All of which have failed.

Because Internet connectivity is sporadic our systems have evolved by necessity to be largely autonomous. IoT sensors and actuators operate according to the logic enforced by Home Assistant. The solar electricity system is managed by the ICC package on Raspberry Pi, utilising serial connections to our Inverter and Battery Monitor, and managing appliance consumption with Sonoff electricity control devices. Time (one doesn't realise how important accurate time is until configuring unmanaged off-grid systems) is provided by GPS.

And so on. Right now the topology is supposed to look like this:

To be fair, whilst I'm in residence this is largely the case. The rest of the time, which is most of the year, only those autonomous components and systems operate nominally because I'm not there to manage the rest.

But all that is about to change. At least I'm hopeful it is.

Last Saturday Elon Musk's Starlink service informed me that I'd been chosen to participate in the New Zealand beta programme, and I'm expecting delivery of the satellite dish next week. I'm extremely hopeful it is going to solve all of my persistent Internet connectivity problems and, appealing very much to my sensibilities, simplify my topology.

But the Starlink service is not without its challenges. Here are some of those I'm considering before the unit is even delivered:

Cost. At $NZ150/month, Starlink isn't altogether cheap for a holiday home that isn't occupied all that often. The solution is to share the connection with those in proximity, by connecting a 13dBi RT2800 antenna/dongle such as this one to Raspberry Pi, then providing guest access with a Captive Portal solution such as NoDogSplash.
Electricity consumption. The Starlink unit consumes ~100 Watts continuously, about the same amount as an old-fashioned fluorescent lightbulb. This doesn't seem like a lot unless your holiday home is off-grid and over-depletion of your battery storage becomes a serious issue after a few cloudy days. The solution is to monitor battery storage capacity with the above-mentioned ICC and power on/off the Sonoff switch Starlink is plugged into via the home automation software, Home Assistant.
Inbound Connectivity. Starlink uses CG-NAT so there isn't a static IP address assigned one can connect to, in order to access our holiday home from elsewhere. This is trivially easy to work-around by establishing an outbound VPN connection to a server I control then routing inbound connections along that established tunnel.
WiFi Calling. Conceptually, WiFi Calling is a solution whereby cellular providers recognise that a cellphone is outside the cellular coverage area but is connected to WiFi, so route calls and messages over that network instead. Unfortunately not all cellular providers support this type of handover and not on all cellphones. Not sure how I'm going to solve for this.

In summary I've expended a lot of time, effort and money endeavouring to get cellular to work for our particular use case and I've failed. I'm not a particular fan of Elon Musk but I'm cautiously confident his Starlink service is going to solve my headache.

-SRA. Auckland, 29/vii 2021.

FB: https://www.facebook.com/simon.anderson.923/posts/10159200643090482
LI: https://www.linkedin.com/feed/update/urn%3Ali%3Aactivity%3A6826466264014303233/

Technology IoT Raspberry Pi