A client device having a networking layer and a network driver layer for transmitting network packets comprising: a plurality of transmit queues configured at the network layer, each of the transmit queues having different packet service classifications associated therewith; a classifier module for classifying packets according to the different packet service classifications, wherein a packet to be transmitted is stored in one of the transmit queues based on the packet service classifications, wherein one or more of the traffic service classifications comprise opportunistic traffic classes and other traffic service classifications comprise non-opportunistic traffic classes; and a socket layer comprising socket transmitting data from an application associated with each traffic service classification, wherein a socket associated with an opportunistic traffic class is automatically suspended in response to detecting a network interface of the client device being throttled.