> ## Documentation Index
> Fetch the complete documentation index at: https://developers.telnyx.com/llms.txt
> Use this file to discover all available pages before exploring further.

# AnchorSite Configuration

> Configure AnchorSite to control which Telnyx PoP handles media routing for SIP calls, with latency-based and manual selection modes.

AnchorSite determines which Telnyx Point of Presence (PoP) handles media routing for SIP calls.

## Configuration modes

### Latency mode

Automatically selects the optimal PoP based on ICMP ping latency measurements to the SIP endpoint.

**Requirements:**

* IP/FQDN authentication: Whitelist Telnyx media IP addresses for ICMP.
* Credential authentication: Include username in `Contact` header or `X-Telnyx-Username` header:

```
Contact: <sip:user@192.0.2.10:5060>
X-Telnyx-Username: connection_username
```

* TeXML: PoP selected based on latency to webhook URL IP.

### Manual mode

Explicitly select a PoP for predictable routing behavior.

**Available PoPs:**

| Value                    | Location                |
| ------------------------ | ----------------------- |
| `Chicago, IL`            | North America Central   |
| `Ashburn, VA`            | North America East      |
| `San Jose, CA`           | North America West      |
| `Toronto, Canada`        | North America Northeast |
| `Montreal, Canada`       | North America Northeast |
| `Vancouver, Canada`      | North America Northwest |
| `London, UK`             | Europe West             |
| `Amsterdam, Netherlands` | Europe                  |
| `Frankfurt, Germany`     | Europe Central          |
| `Sydney, Australia`      | Asia Pacific            |

## Configuration

You can configure AnchorSite in the [Telnyx Portal](https://portal.telnyx.com/#/app/sip-trunking/ip-connections) by editing an IP Connection:

<Frame>
  <img src="https://mintcdn.com/telnyx/53Uwze2vwQbIRyze/img/anchorsite-configuration-dropdown.png?fit=max&auto=format&n=53Uwze2vwQbIRyze&q=85&s=c05c8c10406c1dbb8502530c7dd2d9bf" alt="IP Connection settings in the Telnyx Portal showing the AnchorSite Override dropdown with Latency and manual PoP options" width="1512" height="857" data-path="img/anchorsite-configuration-dropdown.png" />
</Frame>

[PATCH /v2/ip\_connections/{id}](/api-reference/ip-connections/update-an-ip-connection):

```json theme={null}
{
  "anchorsite_override": "latency"
}
```

For manual selection:

```json theme={null}
{
  "anchorsite_override": "Chicago, IL"
}
```

## Failover

If the selected PoP is unavailable (maintenance, outage, health check failure), calls automatically reroute through the next available PoP.