User guide

Wildcard VoIP MGCP
6-3
iMG/RG Software Reference Manual (Voice Service)
6.1.3 Wildcard
MG/RG/iBG support wild card endpoint identifiers.
By default wild card support is disabled.
It can be enabled/disabled via the following CLI command:
voip mgcp protocol set wildcard enable|disable
When wild card support is enabled, MG/RG/iBG replace the local name description part of the endpoint identi-
fier with the “*” char on RSIP messages.
In this case only one RSIP message is sent in order to notify to the call agent that all the endpoints have been
taken out-of-service and are being replaced in service.
6.1.4 Heartbeat
iMG/RG/iBG support the heartbeat mechanism to detect whether User Agents are still active.
Each iMG/RG/iBG voice port has a unique User Agent permanently associated to it.
Heartbeat mechanism is typically requested on deployments that use Network Address Translation (NAT).
The reason for this requirement is that if a NAT binding expires, there is no way for a Call Agent to send an
incoming call to the User Agent as NAT bindings are generated via outgoing UDP packets.
Using a heartbeat mechanism allows the User Agent to detect loss of the NAT binding (due for example to DSL
uplink fails) and recreate it if required.
The heartbeat mechanism is implemented through the use of Audit commands as AuditConnection and Audi-
tEndpoint
iMG/RG/iBG User Agents support a configurable heartbeat timer. The User Agent then waits for either the end
of this timer, the reception of a command for the endpoint from the Call Agent, or the detection of a local user
activity for the endpoint, such as for example an off-hook transition.
If the heartbeat timer expires the User Agent enters the “disconnected” procedure.The User Agents run a fur-
ther disconnect timer and if they do not receive a command from the Call Agent or detect local activity before
the timer expires, the User Agent sends an RSIP disconnected command to the Call Agent.
If it does not receive a response it continues to periodically retry to contact the provisioned Call Agents.
If the Call Agent is using the above heartbeat mechanism, the heartbeat timer should be set to a value that
allows the Call Agent to send an audit command sufficiently often that the User Agent will see at least 3 audit
commands in the heartbeat time interval. This is to prevent a single packet loss causing the User Agent to
become “disconnected”.
By default heartbeat is disabled and can be enabled via the following command:
voip mgcp protocol set heartbeat enable|disable