• Ring frequency/voltage adjustment
• Hookflash detection timing configuration
• Type of Service (ToS) configuration for audio and signaling Ethernet packets
• Debugging and diagnostic tools
Modem Standards
The ATA supports these modem standards:
• V.90
• V.92
• V.44
• K56Flex
• ITU-T V.34 Annex 12
• ITU-T V.34
• V.32bis
• V.32
• V.21
• V.22
• V.23
Fax Services
The ATA 191 supports two modes of fax services:
• Fax pass-through mode: Receiver-side Called Station Identification (CED) tone detection with automatic
G.711A-law or G.711µ-law switching.
• T.38 Fax Relay mode: The T.38 fax relay feature enables devices to use fax machines to send files over
the IP network. In general, when a fax is received, it is converted to an image, then sent to the T.38 fax
device. When the target T.38 fax device receives this image, the device converts the image back to an
analog fax signal. T.38 fax relays configured with voice gateways decode or demodulate the fax signals
before they are transported over IP.
Success of fax transmission depends on network conditions and fax modem response to these conditions. The
network must have reasonably low network jitter, network delay, and packet loss rate.
Note
Related Topics
Configure Fax Services
Cisco ATA 191 Analog Telephone Adapter Overview
10
Cisco ATA 191 Analog Telephone Adapter Overview
Modem Standards