Queuing methods
   

            1.  Fair Queuing :

                           
    This is the simplest method of queuing, In this mehtod on every line we have different queuue for every user , but allocating different queue to each user the whole scheme becomes simple but it offers multitude of diadvantages as the user can use spoofing techniques to get more bandwidth and so harming other applications.

                                                          Time required to enter the packet in specific queue :

                                         Time complexity is O(logn) as we have queues in sorted order.so insertion of a packet in a queue will take very little time.                                                 

                                                         click here to get the details of fair queuing.

               

             2.  Stochastic Fair queuing  :
                       

                                In this queuing method we don't have separate queue for every flow,that is numner of queues are less than number of flows.so if we have any new flow then that flow is associated with the given queue by using some hash scheme.so the number of flows per queue are greater than one.

                                                         Howevere that is not in many cases because this scheme is based on the fact that at any particular time number of active flows are ver less than total number of flows present in a particular line.So even if we keep number of queues less than total number of flows than it is possible in many cases that number of queues will be more than total number of active flows.


            3.  Deficit Round Robin queuing method  :
   
                            In this queuing method round robin scheme is used between the queues,it means that every particular queue will be given equal credit and if particular queue doesn't send any data during a prticular round then that credit will be built for the next round.

            4.  Core stateless Fair queuing method  :

                             It approximates fair queuing in a way that retains the benefits, but reduces the cost. It works by establishing an island of routers that implement the  protocol. The borders of the island do the processing required to approximate queue-relevant flow properties, thereby allowing the core to employ  a fast, simple queuing algorithm.
                               
                                                                        this