If the transmitter does not receive an acknowledgment within a reasonable time, it re-sends the data. A transmitter that does not hear an acknowledgment cannot know if the receiver actually received the packet; it may be that the packet was lost in transmission or damaged; if error detection finds an error, the packet is ignoredor it may be that an acknowledgment was sent, but it was lost. In the latter case, the receiver must acknowledge the retransmission, but must otherwise ignore it. Likewise, the receiver is usually uncertain about whether its acknowledgments are being received.
In this case it is 7. Therefore, a maximum of n-l frames may be sent before an acknowledgment. For example in order to acknowledge the group of frames ending in frame 4, the receiver sends an ACK containing the number 5.
When sender sees an ACK with number 5, it comes to know that all the frames up to number 4 have been received. This means if window size is w, if four frames are sent by source after the last acknowledgment, then the number of frames left in window is w At this point the sender's window will contain six frames 4, 5, 6, 7, 0, 1.
It means window contains spaces for 7 frames. Now, window has shrunk by one, so the receiver may accept six more frame before it is required to send an ACK. The sliding window of the sender expands to right when acknowledgments are received.
The sliding window of the receiver expands to the right when acknowledgement is sent. Dinesh authors the hugely popular Computer Notes blog. Where he writes how-to guides around Computer fundamentalcomputer software, Computer programming, and web apps.
For any type of query or something that you think is missing, please feel free to Contact us.Sliding window is a technique for controlling transmitted data packets between two network computers where reliable and sequential delivery of data packets is required, such as when using the Data Link Layer (OSI model) or Transmission Control Protocol (TCP).
Sliding Window protocol handles this efficiency issue by sending more than one packet at a time with a larger sequence numbers. The idea is same as pipelining in architectures.
Few Terminologies. Stop-and-wait protocol and Sliding window protocol are the methods evolved for handling the flow control of the network data transfers.
These methods mainly differentiated by the techniques they follow such as stop-and-wait uses the concept of the acknowledging each data unit before sending another data unit. Although commonly distinguished from the sliding-window protocol, the stop-and-wait ARQ protocol is actually the simplest possible implementation of it.
The transmit window is 1 packet, and the receive window is 1 packet. Thus, N=1+1=2 possible sequence numbers (conveniently represented by a .
Sliding Window Protocol: In sliding window method, multiple frames are sent by sender at a time before needing an lausannecongress2018.comg window refers to an imaginary boxes that hold the frames on both sender and receiver side.
Craig E. Wills Sliding Window Protocols Sliding Window Protocols Frames are numbered. Lost frames can be retransmitted. Duplicate frames can be deleted. Out of order frames can be reordered. The sender maintains two variables: SL = the number of the \oldest" frame sent, but not ACK’ed.