Скачать или смотреть Dial Up Modem Sounds: K56Flex

Here's the Rockwell standard for 56K, before V.90 was adopted by the industry: K56Flex

Next modulation: Telebit Trailerblazer PEP

If there's something else you'd like to hear, leave me a comment and I'll see what I can do.

Originating modem: Zoom Model 2949L
Answering modem: Patton DialFire 2960 Remote Access Server

Call path is as follows:

Zoom Model 2949L -- FXS port on Cisco IAD2431-16FXS -- PRI port on VConsole 8BRI-U-MOD-2PRI -- Dialogic Diva 4BRI-8 in an Asterisk server -- VConsole 8BRI-U-MOD-2PRI -- Patton DialFire 2960 Remote Access Server

The Asterisk server records the call, putting the caller in the left channel, and the answerer in the right.