Patent ID: 8848579

Claim:
A method of facilitating differential billing among tethered-data and non-tethered-data communications, the method comprising: a wireless communication device (WCD) maintaining correlation data that associates a first set of one or more transport-layer port numbers with tethered-data communication and further associates a second set of one or more transport-layer port numbers with non-tethered-data communication, wherein the first and second sets are mutually exclusive; the WCD making a determination as to whether a payload of a data packet that is to be transmitted from the WCD to a wireless wide-area network (WWAN) is a tethered-data payload or rather a non-tethered-data payload, wherein tethered-data payloads are received by the WCD from at least one tethered device and wherein non-tethered-data payloads originate on the WCD; the WCD selecting a transport-layer source port number based at least in part on the determination, wherein selecting the transport-layer source port number based at least in part on the determination comprises (i) selecting as the transport-layer source port number a transport-layer port number from the first set if the determination is that the payload is a tethered-data payload and (ii) selecting as the transport-layer source port number a transport-layer port number from the second set if the determination is that the payload is a non-tethered-data payload; the WCD modifying the data packet at least in part by inserting the selected transport-layer source port number into a header of the data packet; the WCD transmitting the modified data packet to the WWAN; and the WCD updating the correlation data and transmitting the updated correlation data to at least one network entity on the WWAN.