on the direction. This can be a longest-prefix match (LPM) table. If there is a miss in this table, the default action is to drop the packet. Following the subscriber table is the application table. In this context, "application" refers to the remote communication endpoint, for example, web servers, as identified by the IP address, protocol, and port number. It is used to modify the subscriber's default service set according to any static L3-L4 application policies. Wildcards, pre- fixes, and ranges are permitted in this table. Based on this information, specific services can be excluded from the service set or added to it. Incoming Direction Microflow Subscriber Application Path status Next dst packet table table table table table table table Metadata 64 bits service set [011010] 1 bit for direction Virus scan Content cache 1 bit for one service Figure 5.7 Multiple tables and metadata. 5 SDN and NFV in 5G If there is a miss in this table, the packet is not dropped and the service set is not modified. The path status table follows the application table or Microflow table (will be described in the following section). Its purpose is to determine which services in the service set have already been applied. This is important because a packet may traverse the same perimeter switch multiple times, and it should be treated differently each time. The ingress port is sufficient to provide this information. If this table is reached, it means that the packet has arrived on a node port, connected directly to a service or router. The ingress port then tells us which service was just applied, if any, and it also tells us the direction. There is a global ordering of services in each direction (they may or may not be the exact reverse of each other). Based on the direction and the previous service, the service set is modified to exclude the previous service and all other services that precede it. The final table along the node port path is the next destination table. It uses the direction and the service set as a key. This is a 