Operation; Keepalive Notifications From The Gateway - AudioCodes Mediant 2000 User Manual

7.2.2

Operation

7.2.2.1 Executing MEGACO Commands
MEGACO commands, received from an external Call Agent through the IP network,
are decoded and executed in the Mediant 2000. Both text encoding and binary
encoding are supported. Commands can create new connections, delete connections,
or modify the connection parameters.
Several commands that support the basic operations required to control a Mediant
2000:
Status change command - The command ServiceChange allows changing the
status of one or more Terminations. When used with a special Termination, called
the ROOT Termination, it affects the entire Mediant 2000.
Connection commands - The commands Add, Move, Modify and Subtract allow
the creation and deletion of a call connection inside the Mediant 2000. These
commands allow the application to create new connections, delete existing
connections, and modify the connection parameters.
Notify command - The Notify command is used by the Mediant 2000 to inform the
Call Agent of events occurring on one of the Terminations.
Audit commands - The AuditCapabilities and AuditValue commands are used to
query the Mediant 2000 about Termination configuration and state. This
information helps in managing and controlling the Mediant 2000.
A MEGACO-configured Mediant 2000 starts by sending a ServiceChange command
to its primary MGC. If no response is received from it, the gateway goes on to the next
MGC in its list. When an MGC accepts the Mediant 2000 registration, the session can
start. Subsequently, the Mediant 2000 responds to MGC commands. Event
notifications are sent only if the MGC requests them specifically.
7.2.2.2

KeepAlive Notifications From the Gateway

The Keep Alive notifications from the gateway to the MGC are implemented either
using an AudioCodes proprietary mechanism via a NOP ServiceChange command
(controlled by ini file parameters), or using the standard inactivity timer package
(H.248.14).
For the AudioCodes proprietary mechanism via a NOP ServiceChange command
there are two parameters:
KeepAliveEnabled - activates or de-activate the Keep Alive function
KeepAliveInterval - defines the inactivity period in seconds
If the KeepAlive mechanism is enabled, the Mediant 2000 sends a NOP
ServiceChange command when it detects a defined period without commands from
the MGC (the default period is 12 sec.) If no response is received from the MGC, the
retransmission mechanism is initiated and eventually causes a new ServiceChange
command to be sent to the next available MGC.
For the standard inactivity timer package (H.248.14) Inactivity detection is fully
supported. The activation is by requesting the 'it/ito' event on the root termination. The
'mit' parameter of this event defines the inactivity period in 10 millisecond units. Note
that this function is not set by configuration. The Call Manager must send a request
for this event.
User's Manual 116
Mediant 2000
Document # LTRT-69805