Some implementations provide a method including: storing, at a Network Credit Server (NCS), a service level agreement of a customer; maintaining a database of topology information of the network; receiving a request from a network device where a first plurality of packets associated with the customer have been received en-route to a destination and when the number of the first plurality of packets surpasses a pre-configured threshold number; generating, by the NCS, a reply based on the service level agreement of the customer and the topology information of the network; and sending the reply to the network device for the network device to process a second plurality of packets associated with the customer, the second plurality of packets being received at the network device subsequent to the first plurality of packets and en-route to the destination.