MEGACO is a general-purpose gateway-control
protocol standardized in the IETF as RFC 3015 and as
recommendation H.248 in the ITU-T. It is a master-slave,
transaction-oriented protocol in which Media Gateway
Controllers (MGC) control the operation of Media Gateways
(MG). The MEGACO Stack and other Voice over Packet (VoP)
software solutions from Aricent provide a complete set
of building blocks for quickly developing Next Generation
solutions. The solutions meet the carrier class requirements
of redundancy, scalability and reliability.
MEGACO/H.248 is central to the VoP solutions
and may be integrated into products such as Central
Office Switches, Gateways (Trunking, Residential and
Access), Network Access Servers, Cable Modems, PBXs,
IP Phones, Soft Phones, IADs, Middleboxes etc. to develop
a convergent voice and data solution. Check
out the Aricent MG Toolkit for Rapid implementation
of MG.
MEGACO Stack Context in System
Aricent’
MEGACO/H.248 Stack: Functions
Association management: Creation and
management of control association between MGC and
a MG
Transaction and Command management:
Transaction and Command requests and replies management
ALF support: Ensures reliable delivery
of transactions
Encoding/Decoding in both text and
binary
IN and ATM SDP encoding support
Easy Packages upgrade support ( validation,
addition and editing of packages)
Aricent’
MEGACO/H.248 Stack: Service User Interface
The Service User Interface exposes Protocol
APIs and Management APIs to the service user. It provides
the following functions to the service user:
Interfaces to:
Register with the stack
Configure the protocol parameters
MG/MGC application for sending
protocol messages to the MGC/ MG application
Activate and deactivate management
features of the stack
Protocol trace, statistics collection,
status reporting, error reporting and redundant
mode operation
Flexibility to collate commands into
transactions
Protocol message encoding and decoding
services
Parameter validation services including
package parameter validation.
The interface may operate in the same process context
(functional interface) or a different context (message
based interface) than the core stack
Redundancy Support
The MEGACO/H.248 stack provides multiple
redundancy configurations to support different applications.
Support options include:
Redundant applications
Redundant MEGACO/H.248 stacks
Scalability
The MEGACO/H.248 stack design offers capability
for scaling as the target application grows. Scalability
can be achieved by following means:
Increase the number of call agents
and MG-MGC associations, which the stack handles as
the system capacity grows
Moving from uni-processor environment
to multi-processor target hardware
Moving from a single thread of control
operating system to a multi-tasking real time operating
system
