A network device is configured to transmit acknowledgement packets according to the length of the egress queue. The network device receives data packets from one or more endpoints and buffers the data packets in an egress buffer before transmitting the data packets. The network device also receives acknowledgement packets that are sent in response to data packets previously transmitted by the network device. The network device buffers the acknowledgement packets in an acknowledgement buffer. The network device transmits the acknowledgement packets at an acknowledgment rate that is based on a queue length of the egress buffer.