First Published: August 15, 2025

Release Notes

These release notes support the Cisco 191 Analog Telephone Adapter (ATA) running Firmware Release 12.0(3).

The following table lists the support and protocol compatibility for the Cisco ATA 191.

Table 1. Cisco ATA 191, Support, and Firmware Release Compatibility

Cisco IP Phone

Protocol

Support Requirements

Cisco ATA 191

SIP

Cisco Unified Communications Manager 10.5(1) and later

Cisco Unified Communications Manager DST Olsen version D or later

Related Documentation

Use the following sections to obtain related information.

New and Changed Features

Configurable Cipher Suite

You can disable weak TLS ciphers on ATAs to help enhance the security, protect the communications between the TLS client/server, and reduce the security risks.

To use this feature, configure the parameter Disable TLS Ciphers on Cisco Unified Communication Manager.

Where to Find More Information

Cisco ATA 191 Analog Telephone Adapter Administration Guide for Cisco Unified Communications Manager

TLS 1.3 Support

The ATA registered to Cisco Unified CM now supports the TLS up to the 1.3 version. TLS 1.3 can enhance the security and improve the performance for ATA.

In addition, TLS 1.3 provides a simplified cipher suite:

  • TLS_AES_128_GCM_SHA256

  • TLS_AES_256_GCM_SHA384

  • TLS_CHACHA20_POLY1305_SHA256


Note

To support the TLS 1.3 on the ATA, the required version of Unified CM is 15 SU2 or later.

Where to Find More Information

Cisco ATA 191 Analog Telephone Adapter Administration Guide for Cisco Unified Communications Manager

TLS Minimum Version Control

From this release, you can set the minimum version of TLS required for the TLS communications. The feature is available when the ATA acts as a TLS client or TLS server. With this feature, you can disable certain low versions of TLS (such as, TLS 1.0, TLS 1.1, etc.) to secure the communications between the TLS client and server.

By default, the TLS minimum version for client and server is both TLS 1.2. You can change the setting with Cisco Unified Communications Manager.

Where to Find More Information

Cisco ATA 191 Analog Telephone Adapter Administration Guide for Cisco Unified Communications Manager

User Guide Accessibility

The Cisco ATA 191 User Guide for Cisco Unified Communications Manager is accessible for people with limited sight or who are blind. The HTML version of the document is now compatible with the Job Access With Speech (JAWS) reader, so visually impaired users can access information about their device.

Where to Find More Information

  • Cisco ATA 191 User Guide for Cisco Unified Communications Manager

Installation

Installation Requirements

Before you install the firmware release, you must ensure that your Cisco Unified Communications Manager is running the latest device package. For more information about how to install a Unified CM device package, see Cisco Unified Communications Manager Device Package Installation Guide.


Note

If your Cisco Unified Communications Manager doesn't have the required device package to support this firmware release, the firmware may not work correctly.

For information on the device packages, see the Cisco Unified Communications Manager Device Package Compatibility Matrix.

Install the Firmware Release on Cisco Unified Communications Manager

Before you use the Cisco Analog Telephone Adapter with Cisco Unified Communications Manager 10.5, or higher, you must install the latest firmware on all Cisco Unified Communications Manager servers in the cluster.

Besides Cisco Unified Communications Manager, the Cisco ATA 191 can also work with Cisco Unified Communications Manager Express and Cisco Unified Survivable Remote Site Telephony (SRST). Refer to the Related Documentation section for more information.

Procedure

Step 1

Go to the following URL: https://software.cisco.com/download/navigator.html?mdfid=268437683&flowid=77852

Step 2

Choose ATA 190 Series Analog Telephone Adapters > ATA 191 Analog Telephone Adapter.

Step 3

In the Latest Releases folder, choose 12.0.3.

Step 4

Select cmterm-ATA191.12-0-3-0001-139.k4.cop.sha512 firmware, click the Download or Add to cart button, and follow the prompts.

Step 5

Click the + next to the firmware file name in the Download Cart section to access additional information about this file. The hyperlink for the readme file is in the Additional Information section, which contains installation instructions for the corresponding firmware.

Step 6

Follow the instructions in the readme file to install the firmware.

Install the Firmware Zip Files

Before you use the Cisco Analog Telephone Adapter with Cisco Unified Communications Manager 10.5, or higher, you must install the latest firmware on all Cisco Unified Communications Manager servers in the cluster.

Besides Cisco Unified Communications Manager, the Cisco ATA 191 can also work with Cisco Unified Communications Manager Express and Cisco Unified Survivable Remote Site Telephony (SRST). Refer to the Related Documentation section for more information.

Procedure

Step 1

Go to the following URL: https://software.cisco.com/download/navigator.html?mdfid=268437683&flowid=77852

Step 2

Choose ATA 190 Series Analog Telephone Adapters > ATA 191 Analog Telephone Adapter.

Step 3

In the Latest Releases folder, choose 12.0.3.

Step 4

Select cmterm-ATA191.12-0-3-0001-139.zip firmware, click the Download or Add to cart button, and follow the prompts.

Step 5

Click the + next to the firmware file name in the Download Cart section to access additional information about this file. The hyperlink for the readme file is in the Additional Information section, which contains installation instructions for the corresponding firmware.

Step 6

Follow the instructions in the readme file to install the firmware.

Limitations and Restrictions

Manufacturing Installed Certificate Signature and SHA-256 Support

The manufacturing installed certificate(MIC) signature has been updated from SHA-128 with RSA to SHA-256 with RSA. You must update and install the new SHA-2 certificates on the Cisco Unified Communications Manager for secure mode to function. You can download the new certificate from http://www.cisco.com/security/pki/certs/cmca2.cer.

All applications that authenticate the phone MIC should update the MIC, including the following:

  • Cisco Unified Communications Manager

  • Cisco Unified Survivable Remote Site Telephony

  • Cisco Secure Access Control System

  • Cisco Identity Services Engine

For additional information about SHA-2 use and support, see Security Guide for Cisco Unified Communications Manager (https://www.cisco.com/c/en/us/support/unified-communications/unified-communications-manager-callmanager/products-maintenance-guides-list.html).

Phone Behavior During Times of Network Congestion

Anything that degrades network performance can affect phone audio and, in some cases, can cause a call to drop. Sources of network degradation can include, but are not limited to, the following activities:

  • Administrative tasks, such as an internal port scan or security scan.

  • Attacks that occur on your network, such as a Denial of Service attack.

Caveats

This section describes the resolved and open caveats, and provides information on accessing the Cisco Software Bug Toolkit.

View Caveats

You can search for caveats using the Cisco Bug Search.

Known caveats (bugs) are graded according to severity level, and can be either open or resolved.

Before you begin

To view caveats, you need the following items:

  • Internet connection

  • Web browser

  • Cisco.com user ID and password

Procedure

Step 1

Perform one of the following actions:

Step 2

When prompted, log in with your Cisco.com user ID and password.

Step 3

(Optional) Enter the bug ID number in the Search for field, then press Enter.

Open Caveats

There are no open caveats in this release.

Resolved Caveats

The following list shows the severity 1, 2, and 3 defects that are resolved for the Cisco ATA 191 Analog Telephone Adapter Release Firmware Release 12.0(3).

For more information about an individual defect, access the Bug Search toolkit and search for the defect using the Identifier. You must be a registered Cisco.com user to access this online information.

Because defect status continually changes, the table reflects a snapshot of the defects that were open at the time this report was compiled. For an updated view of open defects, access Bug Toolkit as described in Access Cisco Bug Search.

  • CSCwk58669: ATA 191 doesn't stop local ring back after receiving an UPDATE without ui-state=ringout.

  • CSCwm33267: ATA191 Delayed Voice Channel Setup for Secure SRTP Calls

Access Cisco Bug Search

Known problems (bugs) are graded according to severity level. These release notes contain descriptions of the following:

  • All severity level 1 or 2 bugs

  • Significant severity level 3 bugs

You can search for problems by using Cisco Bug Search.

Before you begin

To access Cisco Bug Search, you need the following items:

  • Internet connection

  • Web browser

  • Cisco.com user ID and password

Procedure

Step 1

To access Cisco Bug Search, go to:

https://bst.cloudapps.cisco.com/bugsearch

Step 2

Log in with your Cisco.com user ID and password.

Step 3

To look for information about a specific problem, enter the bug ID number in the Search for field, then press Enter.