Mumble is a

voice over IP Voice over Internet Protocol (VoIP), also called IP telephony, is a method and group of technologies for the delivery of voice communications and multimedia sessions over Internet Protocol (IP) networks, such as the Internet. The terms Internet t ...

(VoIP) application primarily designed for use by gamers and is similar to programs such as TeamSpeak. Mumble uses a client–server architecture which allows users to talk to each other via the same server. It has a very simple administrative interface and features high sound quality and low latency. All communication is encrypted. Mumble is free and open-source software, is

cross-platform In computing, cross-platform software (also called multi-platform software, platform-agnostic software, or platform-independent software) is computer software that is designed to work in several computing platforms. Some cross-platform software ...

, and is released under the terms of the BSD-3-Clause license.

Channel hierarchy

A Mumble server (called Murmur) has a root channel and a hierarchical

tree In botany, a tree is a perennial plant with an elongated stem, or trunk, usually supporting branches and leaves. In some usages, the definition of a tree may be narrower, including only woody plants with secondary growth, plants that are ...

of channels beneath it. Users can temporarily connect channels to create larger virtual channels. This is useful during larger events where a small group of users may be chatting in a channel, but are linked to a common channel with other users to hear announcements. It also matches team-based

first-person shooter First-person shooter (FPS) is a sub-genre of shooter video games centered on gun and other weapon-based combat in a first-person perspective, with the player experiencing the action through the eyes of the protagonist and controlling the p ...

(FPS) games. Each channel has an associated set of groups and

access control list In computer security, an access-control list (ACL) is a list of permissions associated with a system resource (object). An ACL specifies which users or system processes are granted access to objects, as well as what operations are allowed on gi ...

s which control user permissions. The system supports many usage scenarios, at the cost of added configuration complexity.

Sound quality

Mumble uses the low- latency audio codec

Opus ''Opus'' (pl. ''opera'') is a Latin word meaning "work". Italian equivalents are ''opera'' (singular) and ''opere'' (pl.). Opus or OPUS may refer to: Arts and entertainment Music * Opus number, (abbr. Op.) specifying order of (usually) publicatio ...

as of version 1.2.4, the codec that succeeds the previous defaults

Speex Speex is an audio compression codec specifically tuned for the reproduction of human speech and also a free software speech codec that may be used on VoIP applications and podcasts. It is based on the CELP speech coding algorithm.Xiph.OrIntro ...

and CELT. This and the rest of Mumble's design allow for low-latency communication, meaning a shorter delay between when something is said on one end and when it's heard on the other. Mumble also incorporates

echo cancellation Echo suppression and echo cancellation are methods used in telephony to improve voice quality by preventing echo from being created or removing it after it is already present. In addition to improving subjective audio quality, echo suppression ...

to reduce echo when using speakers or poor quality sound hardware.

Security and privacy

Mumble connects to a server via a TLS control channel, with the audio travelling via UDP encrypted with AES in

OCB mode Offset codebook mode (OCB mode) is an authenticated encryption mode of operation for cryptographic block ciphers. OCB mode was designed by Phillip Rogaway, who credits Mihir Bellare, John Black, and Ted Krovetz with assistance and comments on the ...

. As of 1.2.9 Mumble now prefers ECDHE + AES-GCM cipher suites if possible, providing Perfect Forward Secrecy. While password authentication for users is supported, since 1.2.0 it is typically eschewed in favor of strong authentication in the form of public key certificates.

Overlay

There is an integrated overlay for use in fullscreen applications. The overlay shows who is talking and what linked channel they are in. As of version 1.0, users could upload avatars to represent themselves in the overlay, creating a more personalized experience. As of version 1.2, the overlay works with most Direct3D 9/10 and OpenGL applications on Windows and has OpenGL support for Linux and Mac OS X. Support for DirectX 11 applications was later added.

Positional audio

For certain games, Mumble modifies the audio to position other players' voices according to their relative position in the game. This not only includes giving a sense of direction, but also of distance. To realise this, Mumble sends each player's in-game position to players in the same game with every audio packet. Mumble can gather the information needed to do this in two ways: it either reads the needed information directly out of the memory of the game or the games provide it themselves via the so-called link plugin interface. The link plugin provides games with a way to expose the information needed for positional audio themselves by including a small piece of source code provided by the Mumble project. Several high-profile games have implemented this functionality including many of

Valve A valve is a device or natural object that regulates, directs or controls the flow of a fluid (gases, liquids, fluidized solids, or slurries) by opening, closing, or partially obstructing various passageways. Valves are technically fitting ...

Source Engine Source is a 3D game engine developed by Valve. It debuted as the successor to GoldSrc in 2004 with the release of '' Counter-Strike: Source'' and '' Half-Life 2''. Updates to Source were released in incremental versions, with the engine being su ...

based games (''

Team Fortress 2 ''Team Fortress 2'' is a 2007 multiplayer first-person shooter game developed and published by Valve Corporation. It is the sequel to the 1996 ''Team Fortress'' mod for '' Quake'' and its 1999 remake, '' Team Fortress Classic''. The game was ...

'', '' Day of Defeat: Source'', '' Counter-Strike: Source'', '' Half-Life 2: Deathmatch'') and ''

Guild Wars 2 ''Guild Wars 2'' is a free-to-play, massively multiplayer online role-playing game developed by ArenaNet and published by NCSoft. Set in the fantasy world of Tyria, the core game follows the re-emergence of Destiny's Edge, a disbanded guild ded ...

''.

Mobile apps

Third-party mobile apps are available for Mumble, such a
Mumble for iOS
Plumble for Androi
F-DroidGoogle Play
Note: Discontinued in 2016), and Mumla
F-DroidGoogle Play
.

Server integration

Mumble fits into existing technological and social structures. As such, the server is fully remote controllable over ZeroC Ice. User channels as well as virtual server instances can be manipulated. The project provides a number of sample scripts illustrating the abilities of the interface as well as prefabricated scripts offering features like authenticating users using an existing

phpBB phpBB is an Internet forum package written in the PHP scripting language. The name "phpBB" is an abbreviation of ''PHP Bulletin Board''. Available under the GNU General Public License, phpBB is free and open-source. Features of phpBB include ...

Simple Machines Forum Simple Machines Forum (SMF) software is an open-source web application that provides Internet forum and message board services. It is developed by Simple Machines. The name reflects the creator's initial goal of providing a website that could b ...

database In computing, a database is an organized collection of data stored and accessed electronically. Small databases can be stored on a file system, while large databases are hosted on computer clusters or cloud storage. The design of databases s ...

. The murmur server uses port 64738 TCP and UDP by default. The port number refers to the address of the reset function on a Commodore 64. An alternative minimalist implementation of the mumble-server (Murmur) is called uMurmur. It is intended for installation on

embedded devices An embedded system is a computer system—a combination of a computer processor, computer memory, and input/output peripheral devices—that has a dedicated function within a larger mechanical or electronic system. It is ''embedded'' as ...

with limited resources, such as, for example,

residential gateway A residential gateway is a small consumer-grade gateway which bridges network access between connected local area network (LAN) hosts to a wide area network (WAN) (such as the Internet) via a modem, or directly connects to a WAN (as in EttH), wh ...

s running

OpenWrt OpenWrt (from ''open wireless router'') is an open-source project for embedded operating systems based on Linux, primarily used on embedded devices to route network traffic. The main components are Linux, util-linux, musl, and BusyBox. All ...

Server hosting

Like many other VoIP clients, Mumble servers can be both rented or hosted locally. Hosting a Mumble server locally requires downloading Murmur (included as an option in the Mumble installer) and launching it. Configuring the server is achieved via editing the configuration file. The configuration file holds information for the server's name, user authentication, audio quality restrictions, and port. Administrating the server from within requires a user to be given administrator rights, or can also be done by logging into the SuperUser account. Administrators within the server can add or edit rooms, manage users, and view the server's information.

References

External links

* {{Official website Free software programmed in C++ Free VoIP software Internet software for Linux MacOS Internet software Software using the BSD license Voice over IP clients that use Qt VoIP software Windows Internet software