CODEWITHSUNDEEP
socketstcpnetwork-programmingnetwork-protocols
phsource
phsource

Reputation: 2446

Does TCP Receive Window Size header field include the bytes in segment headers?

I'm working on an implementation of TCP for a class and I'm wondering what the Window Size field actually mean.

I understand that the window size is the number of bytes, but does that number of bytes apply to:

  1. the payload of the TCP Segment, not including the header or to
  2. the entire TCP Segment, including the header?

Thus far, I've looked on Wikipedia:

RFC 793 states that:

The window indicates an allowed number of octets that the sender may transmit before receiving further permission.

RFC 2581 states that:

receiver's advertised window (rwnd) is a receiver-side limit on the amount of outstanding data

Neither of these make it particularly clear. Anyone?

Upvotes: 3

Views: 713

Answers (1)

user207421
user207421

Reputation: 310850

It applies to the payload only. The sender can always transmit ACKs, FINs, RSTs, etc., with no payload.

Upvotes: 5

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