Activating VoIP Services for Assigned IP Subscribers
When the SAE activates VoIP services, signaling proxies must identify subscriber equipment based on the IP address of the equipment. In the enterprise model, an IT manager typically subscribes to a service at a particular level in the subscriber hierarchy, and then provides the service to all access lines and subscribers who are at lower levels in the hierarchy. In cases such as this, the SAE manages the router interface but not the subscriber. The SAE does not know the IP addresses of the subscribers and therefore cannot provide the IP address to the signaling proxies.
A type of subscriber session called assigned IP supports the case in which the SAE does not manage the subscriber but needs to provide the IP address to signaling proxies. The SAE dynamically creates an assigned IP session based on an API call. The VoIP gateway must provide the following information to the SAE before the SAE can create the assigned IP session:
The subscriber’s IP address
The name of a managed interface (The SAE applies policies for service sessions to this interface.)
The name of the virtual router in which the managed interface resides
The NIC maps the subscriber’s IP address to the SAE reference of the managing SAE, the interface name, and the virtual router name and provides this information to the VoIP gateway.
The network information collector (NIC) keeps track of managed interfaces through a NIC SAE plug-in agent. When an interface start, stop, or interim update event occurs, the SAE sends the interface tracking events to the NIC SAE plug-in agent. The NIC uses this information as part of the process of creating these mappings.