Virtual Interface States

Blocked

A virtual interface is in the Blocked state when the interface is Out-of-Service.

While a virtual interface is in the Blocked state, all VPGs do not add new terminations using the interface. Likewise, the VPGs rejects H.248 commands other than Subtract and AuditValue commands on existing terminations on the interface. The error that the VPG returns for commands that it rejects depends on the reason that caused the virtual interface to be Out-of-Service:

• Error #502: "Not ready"—If the virtual interface is Out-of-Service because of an administrative operation.
• Error #529: "Internal hardware failure in PG"—If the virtual interface is Out-of-Service because of a failure.

Forwarding

A virtual interface is in the Forwarding state when it is functioning normally. All gates are using the interface process data flows according to the H.248 properties installed on them.

Draining

A virtual interface enters the Draining state when an administrator instructs the virtual interface to gracefully transition from In-Service to Out-of-Service. The virtual interface automatically transitions to Out-of-Service when it is no longer used by any termination in any of the VPGs.

A virtual interface that is in the Draining state is In-Service and existing gates process data flows normally. However, as in the Blocked state, the VPGs do not add new terminations using that virtual interface or to perform any command other than Subtract and AuditValue on existing terminations on the interface. If the VPG receives other commands, it replies with error #502: "Not ready".