# Cisco ATA 191 adapter

> Connect an analogue phone, fax machine or paging system to your PBX with a Cisco ATA 191 adapter.

- URL: https://kb.voipcloud.online/au/phones-and-apps/other-phones/cisco-ata-191/
- Section: Phones and apps › Other phones and adapters
- Type: guide
- Applies to: All countries
- Last reviewed: 2026-11-09

The Cisco ATA 191 is an analogue telephone adapter. It connects analogue phones, fax machines and overhead paging systems to your PBX. It has two phone ports; each port you use needs its own **SIP device**.

## Before you start

1. Add a **SIP device** to a [User](https://kb.voipcloud.online/au/pbx/accept-make-divert/user/) under **Device configuration**, and click **Apply configuration**.
2. Open **Devices** at the top of the **PBX** tab and select the device. Keep its **SIP credentials** open: **Domain**, **Username** and **Password**.

The **Domain** shows the server address, a colon and the port.

If **Transport protocol** shows **TLS**, [TLS encryption](https://kb.voipcloud.online/au/pbx/settings/general-settings/) is on for your PBX. The port in the **Domain** is then different, and you must set the adapter to use TLS instead of TCP, with SRTP (shown as **Media encryption**).

## 1. Connect the adapter

| Port | What to connect |
| --- | --- |
| **PHONE 1** | Your analogue phone or device. Use this port for a single device. |
| **PHONE 2** | A second analogue device. |
| **INTERNET** | A network cable from your router or switch. |
| **ETHERNET** | Another network device behind the adapter (not recommended). |
| **POWER** | The power adapter supplied with the ATA. |

The **RESET** button restores the factory settings.

## 2. Open the web interface

1. Find the adapter's IP address. One way: on a Windows computer on the same network, run `arp -a` in Command Prompt and look for the MAC address printed on the sticker under the adapter.
2. Type the IP address into your web browser.
3. Sign in with the default details from the quick start guide that came with the adapter.

## 3. Enter the SIP details

**Note:** Menus can change between versions. If a label is different, check the vendor's own help.

On **Quick Setup**, under **Line 1**, fill in:

| Cisco field | What to enter |
| --- | --- |
| **Proxy** | The **Domain**, including the colon and port. |
| **User ID** | The **Username**. |
| **Password** | The **Password**. |
| **Display Name** | Any name you like. |

Click **Submit** at the bottom.

![Cisco Quick Setup with Line 1 Proxy, Display Name and User ID blurred](https://kb.voipcloud.online/au/images/phones-and-apps/other-phones/cisco-ata-quick-setup.webp)

## If it doesn't come online

1. Open the **Voice** tab and choose **Line 1** on the left.
2. Under **SIP Settings**, set **SIP Transport** to **TCP**.
3. Under **Proxy and Registration**, check:
   - **Proxy** matches the **Domain**, including the port;
   - **Register** is **yes**;
   - **Register Expires** is **120**.
4. Submit the changes.

![Cisco Voice tab, Line 1, with SIP Transport TCP and Register Expires 120](https://kb.voipcloud.online/au/images/phones-and-apps/other-phones/cisco-ata-line-1.webp)

## Check it works

1. In **PBX** › **Devices**, the SIP device shows **Online**.
2. Pick up the analogue phone, make a test call, and ask someone to call you.

If it doesn't register, see [Softphone errors](https://kb.voipcloud.online/au/phones-and-apps/softphones/softphone-errors/). A device that tries to register with a wrong password is blocked, and the block lifts after 5 minutes.

## Related

- [Grandstream HT802 adapter](https://kb.voipcloud.online/au/phones-and-apps/other-phones/grandstream-ata/)
- [Devices](https://kb.voipcloud.online/au/pbx/settings/devices/)