I am looking for an audio-loopback solution. Basically what I am trying to do is: I have a SIP phone on the linux box. I need to take the sound output from the SIP phone, and loop it back into the microphone input so I can stream it through an adobe flash encoder stream. The linux box is actually hosted on a VMWare ESX server, so there is no real sound card. I need a piece of software that will, in sense, emulate a sound card, and then loopback the "output" to the speaker, back into the "input" to the microphone. I have a windows piece of software that does it, http://www.ntonyx.com/vac.htm, which basically loops the output back into the input. I have looked at VSound, but I could not seem to get that to work. Any help or suggestions are appreciated! Thanks!

One option would be to use PulseAudio. I don't know what your SIP phone supports, but Pulseaudio offers ALSA, OSS, and ESD support, as well as some others. As for flash, there is a patch which allows Flash to use PulseAudio for output, but I am unsure about input. If you need more help, let me know what your applications support and I may be able to help you witht he correct configuration.

maybe i didn't get your problem, but if it's what i think, a cable can solve this. Buy a plug-to-plug cable, and connect the output to the input doing a "bridge". (in spanish we say "puentear")