Introduction

Whisper is an alternative voice system for OpenSimulator. It consists of an OpenSimulator region module and a Vivox SLVoice.exe replacement that must be installed on every viewer accessing the region using Whisper.

Whisper is implemented using the Mumble open-source voice chat project. On the server side, the Whisper region module connects to an unaltered Murmur server (Murmur is the name of the server component of Mumble). On the client side, the Whisper executable extends the existing Mumble voice client to implement the binary message interface between the SLVoice executable and the main viewer binary. The Mumble version of SLVoice needs to look exactly the same to the viewer as the original SLVoice.exe. The Whisper client is only available for Windows (although Linux and probably Mac OSX versions can be built). The client comes with an installer which replaces SLVoice.exe with the Whisper version and stores the original executable in a same place, so that it can be restored if/when necessary.

Communication between Mumble and the Whisper client is over ICE.

Information is available via these links:

• http://whisper.vcomm.ch/forum
  • Initial Version 27-Dec-2010 - http://whisper.vcomm.ch/forum/viewtopic.php?f=2&t=62
  • Instructions in French - http://angefg.wordpress.com/
• http://mumble.sourceforge.net/

Firewall Information

You only need to open the port(s) mentioned in your OpenSim.ini and murmur.ini files.

• SIP Ports between the viewers and the Mumble server.
• ICE Ports between simulators and the Mumble server.

Mumble/Whisper Test Regions

See whisper test region on Francogrid:

• Hypergrid link at (6995,7004) from OpenSim 0.6.9: 178.63.103.67:9011:WhisperTest
• http://whisper.vcomm.ch/forum/viewtopic.php?f=3&t=66#p102

Limitations

• Whisper does not currently work with simulators running more than one region.
• Each region using the same Mumble server must have a distinct name.

How it works

1. On startup, the region module establishes two connections - one to the mumble server and a callback so that the mumble server can communicate with it.
2. On startup, sets up a voice channel with the name given in the channel_name [MurmurVoice] config parameter (this must currently be the same as the region name - this is why one can only have simulators with one region when using Mumble).
3. TBC

Other OpenSim Voice Solutions

FreeSWITCH - See Freeswitch_Module

Vivox - It is also possible to use the standard Vivox setup if you have access to Vivox services, and a licence to use them in your setup.