Take the 2-minute tour ×
Server Fault is a question and answer site for professional system and network administrators. It's 100% free, no registration required.

OK, this might be a really stupid question, but...

I'm building a web app that utilises websockets. There's fairly rapid messaging going on, so I've been taking a look at the network traffic with wireshark, to see if there's any way of reducing the amount of data we are sending over the wire, and hence costs.

A typical message has approx 150 byte data payload, and according to wireshark the lower layer stuff takes up about: Ethernet: 14 bytes IP: 20 Bytes TCP: 20 Bytes

My question is, are these network headers included in data transfer calculations? What about TCP ACK messages? (another 54 bytes according to wireshark)

This may seem petty, but because we have so much messaging going on, and because the payload is a similar size to these headers, it's significant.

share|improve this question
    
I would guess most people are going to be size of the IP packet. Since pretty much anything in the layer 2 headers is stripped when the packet crosses a router. –  Zoredache Sep 7 '12 at 16:40
add comment

1 Answer 1

up vote 1 down vote accepted

Generally, bandwidth is measured at the IP level. So the Ethernet header does not count, but the IP and TCP headers do. TCP ACK messages are IP packets, so they count too.

share|improve this answer
    
Thank you for clearing that up! –  UpTheCreek Sep 7 '12 at 18:44
add comment

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.