Running servers on phones: the infrastructure behind iproxy.online

iproxy.online, which I co-founded, turns an Android phone into a mobile proxy server. The setup is one Android phone, one SIM card with fast mobile internet and one iproxy.online subscription. One phone can serve up to 15 proxy accesses. Customers connect over HTTP or SOCKS5, or through OpenVPN and WireGuard configs, up to 20 per connection. A full REST API and a Telegram bot handle management, notifications and IP changes.

Behind that setup, every proxy runs on a consumer phone, on a mobile network run by a carrier, in whatever country the customer chose. Each of those three layers has its own habits.

Why people want a mobile IP

Carriers have far fewer IP addresses than they have subscribers, so many people share the same mobile IP at once. A website can’t block that address without blocking the ordinary phone users behind it. Traffic from a real SIM card blends in with regular mobile users, and that is what customers pay for.

The same property rules out shortcuts. The IP has to come from a real carrier through a real SIM, so the proxy has to live on a real phone.

A phone is a demanding server

Phones are built to save battery, and a proxy has to run all day in the background. On some brands those two goals collide. The iproxy.online instructions for Xiaomi, Meizu and Huawei phones tell users to switch off energy saving and allow the app to run in the background. Otherwise the connection can drop.

The other requirements are:

• at least 2 GB of RAM, and phones with ARM Cortex-A53 processors are not recommended
• 4G or LTE for good speed, although 3G works more slowly
• on dual-SIM phones, the SIM goes in slot 1 only
• any monthly data limit set in the phone’s settings has to be removed

iproxy.online keeps a list of recommended devices for people buying hardware for a farm.

Proxies also work over Wi-Fi, but changing the IP needs a SIM card and mobile data.

How the IP changes

When a phone switches airplane mode on and off, the carrier assigns it a new IP address. On most phones that takes 3 to 5 seconds, the time needed to enter airplane mode, leave it and find the network again. Older devices can take 10 to 25 seconds, so the airplane mode duration is adjustable in the connection settings.

Customers can rotate the IP on a schedule, by opening a link or with a Telegram bot command. For work that needs a stable address, sticky sessions keep the same IP across reconnections.

To toggle airplane mode remotely, iproxy.online offers two paths. The Voice Assistant method works on standard Android and takes a couple of clicks, but it can’t reboot the phone and its configuration may reset after a restart. Root access survives reboots and can restart the device, but iproxy.online strongly advises ordinary users against it, because a misconfigured rooted phone can stop working. The recommendation is to start with Voice Assistant and move to root or Macrodroid only if needed.

Every carrier behaves differently

iproxy.online promises “any GEO on Earth”, which means working with whatever carrier the customer’s SIM card belongs to.

On one carrier in Kazakhstan, the IP doesn’t change after airplane mode at all. Belarusian carriers A1 and Life resist rotation in a similar way. Tele2 in Kazakhstan, Latvia and Estonia needs airplane mode held for more than 30 seconds before a new IP arrives. How often an IP can change depends on the carrier and its network settings, so no single setting works everywhere.

Speed depends on the tower. Speed through the proxy is 10 to 15 percent below the lower of the connection’s upload and download speeds, and it changes from second to second with the number of people connected to the same tower.

Private because it’s yours

Buyers of ready-made proxies have to trust the provider about who else uses them. A proxy running on your own phone and SIM is used by nobody else. Owners can check this in their mobile operator account, where no extra traffic shows up. Connection settings include logs of the sites visited through the proxy.

Built for people who resell

Many customers don’t use the proxies themselves. They build farms of phones and sell access to their own users. The pricing reflects that. The Basic plan, $9 per device for 30 days with speed up to 30 Mbit/s, is meant for individuals, small teams and testing. The Pro plan, $12.50 per device for 30 days with unlimited proxy speed, is meant for businesses, farms and sellers, with volume discounts of up to 25 percent. Annual billing takes 20 percent off either plan, and new users get a two-day trial.