What is TCP congestion window size?

TCP Buffer Sizing TCP uses what is called the “congestion window”, or CWND, to determine how many packets can be sent at one time. The larger the congestion window size, the higher the throughput. The TCP “slow start” and “congestion avoidance” algorithms determine the size of the congestion window.

What is the difference between congestion control and flow control in TCP?

The main difference between flow control and congestion control is that the flow control is a mechanism that controls the traffic between sender and receiver. On the other hand, the congestion control mechanism controls the traffic that is placed by the transport layer into the network.

In which TCP algorithm does the size of the congestion window increase?

In the congestion avoidance algorithm, the size of the congestion window increases Additively.

What is flow control?

Flow control is the management of data flow between computers or devices or between nodes in a network so that the data can be handled at an efficient pace. Too much data arriving before a device can handle it causes data overflow, meaning the data is either lost or must be retransmitted.

How do I know what size congestion window I need?

The size of cwnd(congestion window) increases additive. After each RTT cwnd = cwnd + 1. Congestion Detection Phase : multiplicative decrement – If congestion occurs, the congestion window size is decreased. The only way a sender can guess that congestion has occurred is the need to retransmit a segment.

What are bytes flight?

Bytes In Flight – this is the term Wireshark uses to indicate the amount of unacknowledged data a TCP sender has transmitted. It is always less than or equal to the recipient’s receive window.

What is the similarity between congestion control and flow control?

In Flow Control, Traffic is controlled and Traffic represents flow from sender to receiver. In Congestion Control also, Traffic is controlled and Traffic represents flow entering into the network. Data link and Transport layers handles flow control. Network and Transport layers handles congestion control.

What is the size of the congestion window after there is a data loss?

When a packet is lost, the congestion window size is set to 1. Then when we retransmit the packet, if we receive a cumulative ACK for a lot of subsequent packets, we can assume that the packet loss was not due to congestion, but because of some random factors.

How do you calculate congestion window size?

  1. After 1 round trip time, congestion window size = (2)1 = 2 MSS.
  2. After 2 round trip time, congestion window size = (2)2 = 4 MSS.
  3. After 3 round trip time, congestion window size = (2)3 = 8 MSS and so on.