Telegram is the messaging app that governments find hardest to live with. It is run from Dubai, it refuses most data requests, and its public channels can reach millions of people in minutes, which is exactly why it gets switched off when a government wants a protest, a strike or an inconvenient news story to lose its audience. Iran has blocked it since 2018. China never allowed it. Pakistan restricts it. Russia tried to block it for two years, gave up, and then went after its voice calls instead.
The block usually arrives in layers. First the app stores stop offering it, then the DNS names for the main servers stop resolving, then the IP ranges Telegram rents are dropped at the national gateway, and in the most determined countries the traffic itself is recognised by its shape and cut. That last layer is why a plain proxy sometimes stops working after a few days while a VPN keeps going.
Telegram is unusual in that it has its own answer built in. The app can connect through an MTProto proxy, a lightweight relay that disguises Telegram traffic as random data. Thousands of volunteers run them, and Telegram publishes some directly. They work well for chats but they only carry Telegram, they can be slow, and the person running the relay can see which accounts connect through it.
A VPN takes a different route: it wraps everything the device sends in an encrypted tunnel to a server in another country, so the national filter sees only the tunnel. Telegram, its calls, its file downloads and every other app on the phone all come back at once. GhostShield uses WireGuard with ChaCha20 encryption, which the filters that look for VPN traffic have a hard time telling apart from ordinary HTTPS.