By default, the size of the receive window is equal to the size of the send window in the selective replay protocol (SSR), but no information about the specific size was found. In the example where the frame sequence number is represented by 3 bits, the principle that the sending window meets is that the size of the sending window is equal to the receiving window, but the specific size of the receiving window is not specified. "Choose" was equally exciting. Everyone was welcome to read it!
If the size of the reception window in the transmission protocol is greater than 1. The main reasons for the existence of the receiving window were as follows: ** 1. Flow control ** 1. ** Increase reception efficiency ** - The receive window can control the range of data frames that can be received. It allows the receiver to receive multiple data frames within a certain range. In this way, the receiver can avoid frequently interacting with the sender to confirm each data frame one by one, thereby improving the efficiency of receiving data. For example, if the size of the receiving window is three, under suitable network conditions, the receiver can receive and process three data frames at once without waiting for the sender's permission to send each data frame. 2. ** Adapt to the changes in the network environment ** - In a network environment, the data transmission speed might fluctuate. The size of the receiving window can be adjusted according to the network congestion. If the network condition was good, the receiving window could be expanded appropriately to allow more data frames to enter the receiving range and improve the data receiving speed. If the network was congested or unstable, the receiving window could be reduced to avoid receiving too many data frames, resulting in data loss or insufficient processing. ** 2. Data processing ** 1. ** Receiving and processing in an orderly manner ** - The receiving window helps the receiver to receive and process the data frames in an orderly manner. Although the size of the transmit window and the receive window in the selective replay protocol were both greater than 1, the receive window could ensure that the received data frames were within the expected sequence range. If the serial number of the received data frame fell outside the receiving window, the receiver could discard it all. This could ensure that the receiver only processed the data frames that met the requirements, which was convenient for the orderly integration and subsequent processing of the data. 2. ** Cooperate with error handling and replay ** - When a data frame is lost or has an error during transmission, the existence of the receiving window is convenient to cooperate with the re-transmission mechanism of the selective re-transmission protocol. The receiver can feedback which data frames need to be retransmitted to the sender according to the data frames received within the receiving window. Since the size of the receiving window is larger than 1, the receiver can more flexibly deal with various error situations that may occur, such as partial data frame loss or data frame disorder. " Choose " was equally exciting. Everyone was welcome to read it!
In the selection of the re-transmission protocol, the receiving window size must satisfy 1<Wh <= MT (MT is the sending window size). If QR = 1, it is the same as the fallback N frame protocol; if QR> And the transmission window size Wt must be greater than 1 and less than 2^(n - 1)(n is the number of bits that make up the packet sequence number). "Choose" was equally exciting. Everyone was welcome to read it!
For the selective replay protocol, the window size was <=2^(m - 1), and the transmit window could not be larger than the receive window. To maximize efficiency, in most cases, the transmit window was equal to the receive window and was equal to 2n - 1 (n was the number of bits used to number the frame). However, this value must not exceed half of the range of the serial number to avoid the overlap of the new and old receive windows at the receiver. "Choose" was equally exciting. Everyone was welcome to read it!
The size of the sending window of the fallback N-frame protocol is greater than 1, and multiple data packets can be sent consecutively. " Choose " was equally exciting. Everyone was welcome to read it!
In the continuous ARQ protocol, the sender maintained a sending window of a certain size, and the packets within the window could be sent continuously without waiting for the other party's acknowledgment. The sender would slide the sending window forward by one packet every time it received an acknowledgment. The receiver usually uses the method of accumulating acknowledgement, that is, after receiving several packets, it sends an acknowledgement to the last packet that arrives in order, indicating that all the packets up to this packet have been received correctly. However, this method has shortcomings. For example, when the middle packet is lost, the sender cannot know the situation of the subsequent packets, and may need to re-transmit more packets. The sliding window protocol involves a sending window and a receiving window. The transmit window is the range of sequence numbers of the frames that have been sent but have not been acknowledged, and the receive window is the range of sequence numbers of the frames that are expected to be received. When the default window size is 1, you can operate according to the specific sending process. The sliding window protocol could improve the channel utilization and was a reliable transmission mechanism for data communication. The continuous ARQ protocol can be seen as a specific application form of the sliding window protocol under certain conditions (such as the cumulative acknowledgment method). They are all protocol mechanisms that exist to achieve effective and reliable data transmission in the network. "Choose" was equally exciting. Everyone was welcome to read it!
The selective replay protocol was a transport layer protocol. It was a specific example of automatic repeat request (ARQ), which could be used for message unit transmission and confirmation. It was designed to deal with problems such as packet loss, wrong packet, and disorder during network transmission to ensure reliable data transmission. In this protocol, the sending process continuously sends a number of frames according to a window of a specified size, and the receiving process continues to receive and confirm frames after an error occurs. Different from the Fallback N-frame protocol (GGN), it sets up a single acknowledgment, increases the receiving window, and designs a receive buffer to buffer the frames that arrive out of order. This allows only the wrong frames to be retransmitted, thereby improving transmission performance. "Choose" was equally exciting. Everyone was welcome to read it!
In the ARQ protocol, the maximum transmission window is related to the type of the protocol. 1. ** Stop and Wait ARQ protocol **: After sending a frame, the sending station must wait for an acknowledgment signal. After receiving an acknowledgment signal, it will continue to send the next frame. There is no mention of the maximum value of the sending window size. 2. ** Repeat ARQ protocol **: It is a combination of sliding window technology and automatic repeat request technology. The maximum sending window is 2^(n - 1)(considering the possible loss of the ACK, it will be repeated after a time limit). 3. ** Continuous ARQ protocol (includes two types of protocol: - For the backward N-frame protocol, 1 <transmission window <= 2n- 1. - For the selective replay protocol, the transmit window is <= 2^(n - 1), and when the transmit window is the maximum, the receive window = transmit window = 2n - 1. "Choose" was equally exciting. Everyone was welcome to read it!
Selective Repeat Protocol。 " Choose " was equally exciting. Everyone was welcome to read it!
The selection of the replay protocol was set at the transport layer. Transmission layer protocol such as the Transmission Control protocol (TCM) used a packet replay strategy to deal with problems in network transmission to ensure reliable data transmission. Choosing a replay protocol was a way to achieve reliable transmission. It used a specific mechanism to ensure that only the wrong frames were retransmitted during the data transmission process to improve transmission efficiency. These operations were within the scope of the transmission layer. "Choose" was equally exciting. Everyone was welcome to read it!
Fast retransmissions and fast recovery were two concepts in network communication. Fast Retransmission meant that the receiver would immediately send out a repeat acknowledgment after receiving a message segment that was out of order, instead of waiting for a complete message segment to be received before sending out a confirmation. As for fast recovery, it was after a fast replay. In order to avoid network congestion, the sender did not directly enter the slow start phase. Instead, it used a gentler method to adjust the size of the sending window so that the data transmission could quickly recover to normal. These two concepts were mainly used to improve network transmission efficiency and deal with network congestion. " Choose " was equally exciting. Everyone was welcome to read it!