# Network & Mountpoints

RTKdata operates a global RTK corrections network with **20,000+ reference stations** and **99.99% uptime** at the NTRIP endpoints. Under open-sky conditions, most users achieve RTK FIX in **5 to 20 seconds**.

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## Connection Basics

All devices connect using the **NTRIP** (or NTRIPv2) protocol on **port 2101**. Your network must allow **outbound TCP on port 2101**. Firewalls, VPNs, and some mobile carriers can block this port -- see [Troubleshooting](https://docs.rtkdata.com/support/troubleshooting-and-faq) if you have connection issues.

You need NTRIP credentials from the [RTKdata Dashboard](https://rtkdata.com/my-account/rtk-credentials/), not your website email and password. See [Account & Credentials](https://docs.rtkdata.com/get-started/account-and-credentials).

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## Regional Servers

Choose the server closest to your work area. All three servers share the same global base station network; the difference is routing latency.

| Region            | Hostname (preferred) | IP Fallback     | Port   |
| ----------------- | -------------------- | --------------- | ------ |
| **Europe**        | `eu.rtkdata.com`     | `3.73.41.96`    | `2101` |
| **North America** | `rtk.rtkdata.com`    | `13.56.117.10`  | `2101` |
| **Australia**     | `aus.rtkdata.com`    | `54.206.56.130` | `2101` |

**When to use the IP fallback:** Some older Android controllers, tablets, and embedded systems cannot resolve DNS hostnames. If your device fails to connect using the hostname, enter the IP address instead.

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## Mountpoints

RTKdata provides four mountpoints. Names are **case-sensitive** and must be entered in **ALL CAPS**. Use **`AUTO`** unless your project specifically requires a global reference frame.

| Mountpoint          | Description                                                                                                                         |
| ------------------- | ----------------------------------------------------------------------------------------------------------------------------------- |
| **`AUTO`**          | **Recommended.** Delivers corrections in your region's local datum (e.g., NAD83 in the US, ETRS89 in Europe, GDA2020 in Australia). |
| **`AUTO_ITRF2020`** | ITRF2020 at epoch 2015.0                                                                                                            |
| **`AUTO_ITRF2014`** | ITRF2014 at current epoch                                                                                                           |
| **`AUTO_WGS84`**    | WGS84(G2139) at mid-year epoch                                                                                                      |

For the full list of regional datums delivered by `AUTO` per country, see [Coordinate Systems & Datums](https://docs.rtkdata.com/get-started/coordinate-systems-and-datums).

### How AUTO Selects a Base Station

When your device connects and sends its approximate position (via NMEA GGA), the RTKdata caster identifies the nearest reference station and begins streaming corrections from it. If you move across a coverage area, the system can hand off to a closer station automatically. This is why **GGA output must be enabled** -- without your position, the caster cannot assign a base station and you will receive no data. See [NTRIP & GGA Essentials](https://docs.rtkdata.com/integration-hub/ntrip-clients-and-field-software/ntrip-and-gga-essentials) for details.

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## Heights

All corrections are delivered with **ellipsoidal heights**. If you need orthometric (mean sea level) elevations, apply a geoid model in your rover software or during post-processing. See [Understanding Heights](https://docs.rtkdata.com/get-started/understanding-heights) for guidance.

***

## Quick Reference

```
Host:       eu.rtkdata.com / rtk.rtkdata.com / aus.rtkdata.com
Port:       2101
Mountpoint: AUTO
Username:   (from RTKdata dashboard, starts with "rtk")
Password:   (from RTKdata dashboard)
GGA:        ON (required)
```