9
Commands are the major contents in an H.248 message. They control
the Context and Termination attributes including specifying the topology
structure of the Context and specifying the event reported by the
Termination, for example, what signals and actions can be imposed on
the Termination. A command is composed of the command header and
command parameters.
All commands as described in para 7.2 of ITU-T recommendation
H.248.1 version 2 shall be supported:
Add:
To add adds a Termination to a Context. This shall also be used to a
Context when the first termination is added to a
Context.
Modify:
To modify the properties, events, signals of an existing
termination.
Subtract:
To remove a termination from its context. This command is
also used to delete a context when the last termination is removed
from the context.
Move:
To atomically move a Termination to another
Context.
AuditValue:
The AuditValue command returns the current state of
properties, events, signals and statistics of Terminations.
AuditCapabilities:
The AuditCapabilities command returns all the
possible values for Termination properties, events and signals allowed
by the Media Gateway.
Notify
: This command allows the MG to inform the MGC of the
occurrence of events in the MG.
ServiceChange
: To allows the Media Gateway to notify the Media
Gateway Controller that a Termination or group of Terminations is about
to be taken out of service or has just been returned to service.
ServiceChange shall also be used by the MG to announce its availability
to a MGC (registration), and to notify the MGC of impending or
completed restart of the MG. The MGC may announce a handover to the
