What is 2MSL in TCP?

Solution. Generally speaking, the 2MSL (or 2 x MSL) timer refers to a ‘timeout’ value that is specified in RFC 793 (TCP) as part of the ‘Closing’ process of any TCP connection. A TCP connection may be in the ‘Closing’ state for 2MSL seconds before it is removed from the table (as per the RFC).

Why time_ wait 2MSL?

In fact, in general, RTO is much smaller than MSL, but considering the worst case, RTO is 2MSL, so the TIME_WAIT state is 2MSL to ensure that the worst case can also receive the FIN that is retransmitted over time. The time of TIME_WAIT is another important reason for 2MSL.

Which is correct about TCP?

Explanation: TCP provides stream oriented delivery between hosts communicating via an IP network and there are no message boundaries. TCP can concatenate data from a number of send () commands into one stream of data and still transmit it reliably. 3. TCP process may not write and read data at the same speed.

What is 2MSL wait state?

The 2MSL timer makes the client wait for a duration that is enough time for an ACK to be lost (one SML) and a FIN to arrive (another SML). If during the TIME-WAIT state, a new FIN arrives, the client sends a new ACK and restarts the 2SML timer. A duplicate segment from one connection might appear in the next one.

Why do we need Time_wait?

There are two reasons for the TIME_WAIT state. The first is to prevent delayed segments from one connection being misinterpreted as being part of a subsequent connection. Any segments that arrive whilst a connection is in the 2MSL wait state are discarded.

What is TCP in computer network?

TCP stands for Transmission Control Protocol a communications standard that enables application programs and computing devices to exchange messages over a network. It is one of the most commonly used protocols within digital network communications and ensures end-to-end data delivery.

Why is UDP better for video streaming?

UDP offers reduced latency over the TCP reliability. In case of time sensitive applications, UDP is faster protocol as it doesn’t wait for acknowledgement from the client side and retransmission of lost packet.

What is the significance of Time_wait state of TCP?

The purpose of TIME_WAIT is to keep a connection accepting packets even after the connection has been closed. This is because Internet routing can cause a packet to take a slow route to its destination and it may arrive after both sides have agreed to close.

What causes Close_wait?

‘CLOSE_WAIT’ state on tcp connections occurs if the system has not received a close system call from the application, after having received notification (‘FIN’ packet) from the other system that it has closed its endpoint.

When did RFC 1323 lock up the connection?

RFC 1323 TCP Extensions for High Performance May 1992 lock up the connection so that no further progress can be made, forcing an RST on the connection. TCP reliability depends upon the existence of a bound on the lifetime of a segment: the “Maximum Segment Lifetime” or MSL.

Why is sack not included in RFC 1072?

RFC-1072 defined a new TCP “SACK” option to send a selective acknowledgment. However, there are important technical issues to be worked out concerning both the format and semantics of the SACK option. Therefore, SACK has been omitted from this package of extensions.

What is the window size limit in RFC 1323?

RFC 1323 TCP Extensions for High Performance May 1992 (1) Window Size Limit The TCP header uses a 16 bit field to report the receive window size to the sender. Therefore, the largest window that can be used is 2**16 = 65K bytes.

What does port reuse mean in MSL and TCP?

Lately during some support work, a customer raised an interesting case regarding what was referred to as “port reuse”. This lead to quite a nice investigation on the effect of the MSL and TIME_WAIT characteristics of TCP. So first we should define these terms and what exactly they mean.