TCP MSS

[sivam siva]

Who determines the MSS value? sender or receiver?

I believe "receiver",  any thoughts?

[balaji.bandi · Accepted solution]

Its all depends on who intiating the connection.

Suggest to watch an video which explain , how MTU and MSS work and configurable.

https://www.youtube.com/watch?v=XMcYwr-yJGA

Cisco explanation :

https://www.youtube.com/watch?v=XMcYwr-yJGA

More information can be find in RFC , i you intrested deep dive.

https://tools.ietf.org/html/rfc879

[Joseph W. Doherty]

"Who determines the MSS value? sender or receiver?"

Both. (NB: in can differ, based on direction of data flow.)

Balaji's RFC reference has the details.

[sivam siva]

Hi   @balaji.bandi  @Joseph W. Doherty

Thanks for the reply

Let's say host A and B are communicating

A------packet---->B  = B determines the MSS

A<------packet----B = A determines the MSS 

the receiver will always instruct the sender to limit the MSS that the receiver can accept. Am I right?

Thanks 

Siva

[Joseph W. Doherty · Accepted solution]

Almost correct. The receiver does "instruct" the sender, but doing so is an option.