Media Gateway (MG) Stack

MG(4) provides an introductory manual page for MG Switching stack components and interfaces. You can also select one of the component or interface sections from the diagram below:

Components

Interfaces

Components

MG Stack Manager (MGLM)

This section provides a roadmap to Manual Pages for Voice over IP (VoIP) Stack Manager (VoIP SM).

Media Gateway (MG)

This section provides a roadmap to Manual Pages for Media Gateway (MG).

H.248/MEGACO

This section provides a roadmap to Manual Pages for Media Gateway Control (H.248/MEGACO).

Media Gateway Control Protocol (MGCP)

This section provides a roadmap to Manual Pages for Media Gateway Control Protocol (MGCP).

Channel Driver

This section provides a roadmap to Manual Pages for Multiplex/Channel (MX/CH).

Real-Time Transport Protocol (RTP)

This section provides a roadmap to Manual Pages for Real-Time Transport Protocol (RTP).

MG

Section: OpenSS7 STREAMS Channels Devices (4)
Updated: 2008-10-31
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NAME

MG - OpenSS7 Media Gateway Devices

SYNOPSIS

#include <sys/stropts.h>

int mg_stream = open(mg_device, flags);
int retval = ioctl(mg_stream, I_PUSH, mg_module);

DESCRIPTION

The OpenSS7 call framework, cframe(3), approach to call processing is to separate service logic, call control and media control into separate interfaces. This permits service logic, call control and media control components to be mixed and matched in support of local and remote nodes.

The Media Gateway, MG, components of this model are described here. The MG components are responsible for the media control of the triple-headed call processing model. To accomodate media control, the OpenSwitch framework describes interfaces at three levels as follows (beginning from the uppermost level):

mgi(7): Media Gateway Interface is an interface peculiar to the OpenSS7 stack that provides control over Media Gateways using a number of protocols as provided by some of the drivers listed below.
mxi(7): Multiplex Interface is an interface peculiar to the OpenSS7 stack that provides access to channel multiplexers for use by media gateway control above.
chi(7): Channel Interface is an interface peculiar to the OpenSS7 stack that provides access to channels for use by channel multiplexers and the media gateway control above.

The MG related collection of drivers and modules provide the Media Gateway control capabilities in a number of related forms, including local switching, MGCP, H.248, H.245 and GSM-A variants.

DRIVERS

MG provides the following STREAMS(4) pseudo-device drivers:

mgc(4): is a pseudo-device driver that provides distributed switching access to other media gateway devices supporting the Media Gateway Interface, mxi(7). This includes both local switching control using the mg(4) driver, as well as remote switching control using the mgcp(4) and h248(4) drivers. This driver also provides the cornerstone of redundant media gateway control in that it permits both local and remote control of media gateways.
mg(4): Local switching is a local switching driver that provides media gateway control of local switching matrices. This provides mgi(7) control of local interface devices. This supports the linking of streams supporting the Multiplex Interface, mxi(7), and Channel Interface, chi(7), such as local device drivers and RTP multiplexes.
mgcp(4): Media Gateway Control Protocol (MGCP) is a pseudo-device driver that provides an mgi(7) interface for both MG- and MGC-mode nodes, providing media gateway control of both local and remote media gateways using the MGCP protocol
h248(4): MEGACO/H.248 is a pseudo-device driver that provides an mgi(7) interface for both MG- and MGC-mode nodes, providing media gateway control of both local and remote media gateways using the MEGACO protocol.
mx(4): Local Multiplex is a local multiplex driver that provides a Multiplex Interface (MXI), mxi(7), adding multiplex support to local channel devices conforming to the Channel Interface (CHI), chi(7).

MODULES

MG provides the following STREAMS(4) pushable modules:

rt(4): Real-Time Transport Protocol (RTP) is a pushable module that provides Channel Interface, chi(7), interface to RTP streams providing for switching of RTP streams using the local switching model of the mg(4) driver.

DEVICES

MG provides the following STREAMS(4) device drivers:

x100p(4)
x400p(4)
pca200e(4)

NOTICES

The devices, drivers and modules associated with the MG subsystem change rapidly and have not yet finalized. The list presented in this manual page may be out of date.