Systems and methods are disclosed for subscriber sampling for network packet forwarding based upon unique subscriber identifiers. Control packets within input packets are processed to identify unique subscriber identifiers and related session identifiers, which are stored in records within a tracking table. Each input packet is analyzed to extract a session identifier and a unique subscriber identifier if present within the input packet. When a unique subscriber identifier is not present, the tracking table is accessed to determine a unique subscriber identifier associated with the session identifier extracted from the packet. The input packet is sampled based upon the unique subscriber identifier to determine whether or not to output the input packet as a sampled packet. The subscriber sampling can include hash-based sampling, dynamic function based sampling, and/or other subscriber/call based sampling methods. Sampled packets are forwarded to egress port(s) for further processing.