Free voice over ip software for linux

Shell over ICMP consists of two free and open source applications: one server and one client. Shell over ICMP project allows a user to connect to a remote shell daemon, by using ICMP protocol instead of classical TCP.
Entirely written in Python, soicmp is a working proof-of-concept to demonstrate that data can be transmitted across a network by hiding it in traffic that normally does not contain payloads.
How does it work?
The soicmp server is a daemon that must be started on the remote server. When the server receives a request from the client it looks into the packets payload. The payload must respect certain protocol rules. In detail the client must specify:
command
communication mode (echo|echo/reply)
authentication (y|n)
This is an example of a correct payload string sent by client to server:
$CMD ls -a $MODE echo/reply $PWD root2005 $END
If the payload matches with the server protocol specification then it will pipe the command to "/bin/sh" or "cmd.exe" and execute it. The server then reads the result from the pipe and sends it back to the client that will print it to stdout.
Moreover every client will send ICMP packets having id equal to the clients current process ID and will accept only ICMP replies having the same id value. This prevents output to be printed by other client instances running on the same workstation (this argument is also treated in the FAQs section).
Main features:
- Platform independent.
- Possibility to run soicmp daemon on multiple ethernet interfaces simultaneously handling multiple client connections.
- Possibility to specify the buffer size of outgoing packets.
- Client side source IP address spoofing.
- Remote client case-sensitive (plain texted) authentication.
- Possibility to select two communication types:
- One based on encapsulating command output in unique "one way" ICMP_ECHOREPLY (type 0) packets sent by server to client (see fig. 1).
- Another one that guarantees the correct packets delivering by using the request/response nature of ECHO and ECHOREPLY ICMP packet types (see fig.2)
- No listening sockets are listed by netstat or similar programs.

Local IP Takeover provides network link redundancy within a single server that has multiple network interface cards (NICs) with each NIC connected to separate network switches.
If the primary NIC fails (i.e. it cannot ping its default gateway), the "service" IP (the IP that the outside world connects to) will automatically float to the secondary NIC and a specially crafted ARP (utilizing send_arp) will be broadcast on the local network, thereby instructing all other hosts to update their local ARP cache.
The result is minimal service downtime. Plus, no manual intervention is required in the event that a network card, cable, or switch breaks.
Enhancements:
- The initialization step is more robust and it doesnt allow lipt to abort its execution. Instead, lipt should recover to a sane state eventually (within less than half a minute under normal circumstances).
- Other minor fixes were made.

PHP Voice (formerly known as PHP VXML) contain four classes that assist in developing voice application using PHP.
PHP Voice supports Speech Synthesis Markup Language 1.0, Speech Recognition Grammar Specification 1.0, Voice Browser Call Control: CCXML 1.0, and Voice Extensible Markup Language (VoiceXML) 2.0.
Enhancements:
- An improved menu module to support arrays as parameters with the ID of the menu.
- An improved home application with the new menu module.

Ventrilo is the next evolutionary step of Voice over IP (VoIP) group communications software. Ventrilo is also the industry standard by which all others measure them selves as they attempt to imitate its features.
By offering surround sound positioning and special sound effects on a per user, per channel, per server or global configuration level the program provides each user the option to fully customize exactly how they wish to hear sounds from other users or events.
Ventrilo is best known for its superior sound quality and minimal use of CPU resources so as not to interfere with day to day operations of the computer or during online game competitions. It is also preferred for the simple user interface that any first time computer user can very quickly learn because the most commonly used features are immediately visible and can be activated with a single click of the mouse.

IPAC-NG is the iptables/ipchains based IP accounting package for Linux.

It collects, summarizes, and nicely displays IP accounting data. Its output can be a simple ASCII table, or graph images. Ipchains and iptables are supported. Logs are stored in files, gdbm, or PostgreSQL database.

ipac consists of one perl script and one C program:

- fetchipac, executed from cron once in a while, reads the current ip accounting data assembled by the kernel and stores it into a database

- ipacsum summarizes the data from a set of records from the database and, optionally,
replaces these records by one. It displays the values as a simple table containing the sums, as png graph pictures or as ascii graph pictures.

I Hear U is a Voice over IP (VoIP) application for Linux and it creates an audio stream between two computers in the easiest way and with the minimal traffic on the network.
I Hear U major features:
- Peer-to-Peer: the communication takes place between two computers without need of other servers and protocols in the middle.
- UDP/TCP support: IHU supports both UDP and TCP, with the possibility to choose UDP, for fast and easy connections, or TCP, if its the only solution when your computer is behind firewall or NAT.
- Good audio performance: IHU was born to give the best audio performance, low latency above all. For this purpose IHU is compatible with ALSA, now the default Linux sound architecture, but also with JACK, a low latency sound server. For the audio compression, IHU uses Speex, a codec optimized for speech (and completely free and open source).
- Crypted stream: you have also the possibility to crypt the stream using a fast hybrid cryptographic system (RSA + Blowfish)
- Command-line support: the GUI is not strictly necessary, you can run also a textual IHU from command-line (for example if you need to run the program on remote computers).
- Free and Open Source: IHU is totally free and distributed under the terms of GNU General Public License
The possibilities of use of IHU are infinite, for example you can use it like a phone to talk with your friends all around the world, or at home/work, to talk between computers in the LAN, etc., use it just as your phantasy suggests.
Main features:
- feature improved: ring volume adjustable
- bugfix: mute playback when seeking files
- source code: updated to speex 1.1.11
Enhancements:
- new feature: added possibility to convert IHU files to SPX file
- feature improved: quickly change port in the Receiver address using :
- feature improved: Defaults button in settings now affects only current tab
- feature improved: Volume Change speed for AGC changed to slider in the GUI
- bug fixed: TX dump file was closed after first call
- bug fixed: problems when playing files with different Speex modes
- bug fixed: conflict in the GUI when wating for calls and playing files
- source code: clear distinction in the use of h and hpp header

GENRIP is a kernel driver (presently for Linux only) that enables you to carry ethernet frames over generic low-speed/low-power serial radios, such as Microhards MHX series radios. It is intended to speed up the development cycle for those creating low-powered Embedded telemetry and SCADA devices, but may have other applications as well. Once installed, the serial radio simply appears as a network interface like this:

[root@lindev]# ./ifconfig gr0
gr0 Link encap:Generic Radio IP HWaddr 00:00:02:04:06:08
inet addr:192.168.15.1 Mask:255.255.255.0
UP RUNNING MTU:234 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:30
RX bytes:0 (0.0 b) TX bytes:0 (0.0 b)

GENRIP was originally based upon Stuart Cheshires STRIP driver, which is part of the Mobile Computing Group at Stanford Universitys Mosquitonet project. It has been radically modified since.

GENRIP was ported to this application by Lawrence Wimble of Design On Demand, Inc. Design On Demand, Inc. maintains GENRIP and hopes that youll call them if you need help with an embedded project using GENRIP (or any embedded project for that matter).

GENRIP is released for Linux under the GPL. A port to FreeBSD is planned in the near future.