established to switch from voice mode to T.38 mode. Cisco Unified Communications Administration allows
you to configure a SIP profile that supports T.38 fax communication.
The ATA 191 only supports T38 Fax Relay Version 0 (G3).
Supported Voice Codecs
The ATA 191 supports these voice codecs:
• G.711 mu-law
• G.711 A-law
• G.729a
• G.729ab
Check your other network devices for the codecs they support.
Other Supported Protocols
The ATA supports these additional protocols:
• 802.1Q VLAN tagging
• Cisco Discovery Protocol (CDP)
• Domain Name System (DNS)
• Dynamic Host Configuration Protocol (DHCP)
• Internet Control Message Protocol (ICMP)
• Internet Protocol (IP) v4 and IPv6
• Link Layer Discovery Protocol (LLDP)
• Secure Real-Time Transport Protocol (SRTP)
• Transmission Control Protocol (TCP)
• Trivial File Transfer Protocol (TFTP)
• User Datagram Protocol (UDP)
• Transport Layer Security (TLS)
• Secure Socket Shell (SSH)
• Network Time Protocol (NTP)
• HyperText Transfer Protocol (HTTP)
Supported SIP Services
The following SIP services are supported on the ATA:
• IP address assignment—DHCP-provided or statically configured
• ATA 191 configuration by Cisco Unified Communications Manager configuration interface
Cisco ATA 191 Analog Telephone Adapter Overview
8
Cisco ATA 191 Analog Telephone Adapter Overview
Supported Voice Codecs