> ## Documentation Index
> Fetch the complete documentation index at: https://help.decodo.com/llms.txt
> Use this file to discover all available pages before exploring further.
# Introduction
> Mobile Proxy Advanced Parameter Specification to Control Your Connection
Decodo offers customizable proxy access through a single **backconnect** endpoint and port: `gate.decodo.com:7000`.
To specify all proxy parameters in your request, you can use one of two methods:
1. [**Username and Password**](https://help.decodo.com/docs/mobile-proxy-user-pass-requests#/).
2. [**Whitelisted IP**](https://help.decodo.com/docs/mobile-proxy-whitelisted-ip-requests#/).
***
## Available Parameters
| Parameter | Example Value | Description |
| ----------------- | ----------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `country` | `us` | Country code. Please provide it in a two-symbol ISO format. You can check most ISO country codes [**here**](https://www.iban.com/country-codes). |
| `city` | `berlin` | City name. Adding this parameter allows you to specify the city of the IP address you want to use. Please use this parameter together with the `country` parameter. |
| `state` | `us_california` | US state. Supports the **USA** location when you pick `us` as the country parameter. It will allow you to specify the US state of the IP you want to use. |
| `session` | `randomstring123` | A random string is used to create a session, allowing the same IP to be used for more than one request. The session automatically expires within `10` minutes by default. After that, a new IP will be assigned to this session’s ID. |
| `sessionduration` | `180` | Used with `session`. Specifies the sticky session time in minutes – can be set to any number between `1` and `1440` to override the `10` minute sticky session default. |
| `zip` | `10001` | **5-digit**`ZIP` code. Adding this parameter allows you to specify the ZIP code location you want to target. It is only applicable for targeting the **USA** location and should be used with the `country-us` parameter string. |
| `asn` | `20057` | Target the ASN number of a specific carrier. You can look up carrier numbers by searching online, for example, [**here**](https://asnlookup.com). |
| `continent` | `as` | Continent code. |
### ASN Filtering
* You must choose between `city` targeting and `asn` targeting, as they can’t be used simultaneously.
* The same logic would apply to the `continent`, `state` and `country` parameters.
***
## Application Support
### User:pass method
The backconnect entry node can also be used in various applications. In such a case, you will need to pass every parameter for your session alongside the username in the **username** field, like this:
`user-username-country-country_code-city-city_name-session-randomstring`
In the example above,`username` represents your proxy username, which you would need to get from the authentication section. In the `password` field, you only need to enter the proxy user's password.
More info is available in our [**User:pass Requests**](https://help.decodo.com/docs/mobile-proxy-user-pass-requests) section.
The **session ID** can be defined by any string of your choice (simply replace the "randomstring123" from the examples). Use a **Session ID** only if you want a sticky session. Otherwise, just ignore that part to receive a **rotating proxy**.
Use underscores when a city or state name consists of multiple words. E.g: `las_vegas`, `us_new_york`or `us_rhode_island`.
### Whitelisted IP method
Since this method does not include a username, you will have to specify the backconnect parameters in the **endpoint** like this:
`https://country-country_code-city-city_name-session-randomstring.gate.smartproxy.com:7000`
More info is available in our [**Whitelisted IP Requests**](https://help.decodo.com/docs/mobile-proxy-whitelisted-ip-requests) section.
### Whitelisted IP authentication limitations
* **Whitelisted IP** authentication only supports `HTTPS` requests.
* `IPv6` IP addresses are currently unsupported for Whitelisted IP authentication. Please use IPs that are in `IPv4` format (`xx.xx.xx.xx`).
***
## cURL Examples
To use these commands, just replace `username` and `password` with your proxy user credentials and run them in your Terminal or Command Prompt.
##### Get an IP from a random location with a rotating session
```shellscript cURL theme={null}
curl -U "username:password" -x "gate.decodo.com:7000" "https://ip.decodo.com/json"
```
##### Get an IP from a specific country (in this example, Italy) with a rotating session
```shellscript cURL theme={null}
curl -U "user-username-country-it:password" -x "gate.decodo.com:7000" "https://ip.decodo.com/json"
```
##### Get an IP from a specific city (in this example, London) with a rotating session
```shellscript cURL theme={null}
curl -U "user-username-country-gb-city-london:password" -x "gate.decodo.com:7000" "https://ip.decodo.com/json"
```
##### Get an IP from a specific US state (in this example, California)
```shellscript cURL theme={null}
curl -U "user-username-country-us-state-us_california:password" -x "gate.decodo.com:7000" "https://ip.decodo.com/json"
```
##### Get an IP from a specific ASN (in this example, AT\&T Mobility LLC) with a rotating session
```shellscript cURL theme={null}
curl -U "user-username-asn-20057:password" -x "gate.decodo.com:7000" "https://ip.decodo.com/json"
```
##### Get an IP from a specific country (in this example, Portugal) with a session ID
```shellscript cURL theme={null}
curl -U "user-username-country-pt-session-randomstring123:password" -x "gate.decodo.com:7000" "https://ip.decodo.com/json"
```
##### Get an IP from a specific US location using ZIP code (in this example, New York) with a session ID and a 30-minute session duration
```shellscript cURL theme={null}
curl -U "user-username-country-us-zip-10001-session-randomstring123-sessionduration-30:password" -x "gate.decodo.com:7000" "https://ip.decodo.com/json"
```
When using any backconnect parameter, your username is also considered one of the parameters. Therefore, you need to add `user-` prefix before specifying your username, just like with all other parameters.
***
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