Analogue Telephone Adapter Cisco ATA 191, 2-Port Handset-to-Ethernet, SIP, G.711/G.726/G.729, T.38 Fax

The Cisco Analogue Telephone Adapter (ATA) 191 is a compact 2-port handset-to-Ethernet device that converts standard analogue telephones and fax machines into SIP-based VoIP endpoints. Designed for enterprise networks, small offices and UCaaS deployments, the adapter supports multiple voice codecs and T.38 fax relay to maintain voice and fax interoperability when migrating analogue equipment to IP networks. The unit offers essential security and management features while maintaining a small footprint suitable for desktop or wall-mount installations.

Advantages

The ATA 191 supports SIP signaling and a range of codecs including G.711µ/G.711a/G.726/G.729A/G.729ab, enabling compatibility with diverse VoIP environments and optimizing bandwidth usage. T.38 fax relay preserves reliable fax transmission over packet networks. Built-in network protocol support (TCP/UDP/RTP/HTTP/ARP/RTCP/ICMP/LLDP) and management via SNMPv3 simplify integration and monitoring. Security features such as AES encryption, HTTPS and SSH administration protect signalling and management traffic. Its compact dimensions (100×100×28 mm) allow flexible placement in constrained spaces.

Suitable for

• Converting analogue telephones to SIP VoIP endpoints in small offices
• Connecting fax machines to IP networks with T.38 fax relay
• Maintaining legacy handsets during phased VoIP migration in enterprises
• Deployments requiring secure remote management and monitoring

Key specifications

• Ports: 2 analogue handset ports to Ethernet
• Signalling: SIP
• Voice codecs: G.711µ, G.711a, G.726, G.729A, G.729ab
• Fax support: T.38 fax relay
• Network protocols: TCP, UDP, RTP, HTTP, ARP, RTCP, ICMP, LLDP
• Management: SNMPv3 support
• Security: AES encryption, HTTPS, SSH for secure administration
• Physical size: 100 × 100 × 28 mm

How to use

Connect the analogue handset or fax device to one of the two analogue ports and attach the Ethernet cable to your LAN. Configure SIP account settings on the device using the web interface or centralized provisioning system supported by your UCaaS or IP telephony platform. Select appropriate voice codec priorities to match your network bandwidth and quality requirements, and enable T.38 where reliable fax transmission is required. Use SNMPv3, HTTPS or SSH for secure device management and monitoring once the adapter is provisioned.

Usage recommendations

For optimal voice quality, prioritize G.711 codecs on networks with adequate bandwidth and use G.729 variants where bandwidth is limited. Enable T.38 for fax-critical lines and apply SNMPv3 and HTTPS to ensure secure operational monitoring. Place the adapter near the analogue devices or in a network closet with easy Ethernet access; ensure firmware is kept up to date via your provisioning system.