QUEUING:

• FIFIO QUEUING
• Simple and easiest to implement
• Only one parameter used is queue-depth
• Other queuing methods change the order of packets
• We cannot modify the tx-ring, only modify the output queue
• Tx-ring is controlled by clocking & serialization of line
• Controlled by how large the buffer as waiting to send traffic to tx-ring
• To config fifo disable previous queueing mechanisms
• At txr serialization of packet ocuurs
• After filling the output queue, if packets are arrived at tail of queue will be tail dropped
• TCP window: A TCP window is the amount of unacknowledged data a sender can send on a particular connection before it gets an acknowledgment back from the receiver, that it has received some of the data.
• Tcp sliding window:
• The sending device can send all packets within the TCP window size
• (as specified in the TCP header) without receiving an ACK,
• and should start a timeout timer for each of them.
• After receiving the ACK from the receiving device, the sending device slides the window.
• In this case, the sending device can send up to 5 TCP Segments without receiving an acknowledgement from the receiving device.
• After receiving the acknowledgement for Segment 1 from the receiving device, the sending device can slide its window one TCP Segment to the right side and the sending device can transmit segment 6 also.
• If any TCP Segment lost whiles its journey to the destination, the receiving device cannot acknowledge the sender.
• Consider while transmission, all other Segments reached the destination except Segment 3.
• The receiving device can acknowledge up to Segment 2.
• At the sending device, a timeout will occur and it will re-transmit the lost Segment 3.
• Now the receiving device has received all the Segments, since only Segment 3 was lost.
• Now the receiving device will send the ACK for Segment 5, because it has received all the Segments to Segment 5.
• Acknowledgement for Segment 5 ensures the sender the receiver has succesfully received all the Segments up to 5.
• defaultly faire queue is there, based on the weight of packet, packet will be switched
• before configuring fifo remove defaultly enabled fair queue
• hold-queue : no.of packets in fit in software queue
• serialization of pakcet: put the packets into the wires/optical interface , it will be done at TxRing