Hi.

Checking my network monitor when i'm connected to internet i've found that the Datagrams send are equal to Datagrams Delivered, but Datagrams IN are not equal to the Datagrams OUT...¿why?....also, Segments Received are different to Segments Delivered. Could someone please explain this to me? And what's the main different between Datagrams and Segments.
Thanks a lot,

__________________
Best Regards
José A. Campo
MCSA, Net+, A+, CST



Colombia: flowers, rivers, oceans, soccer...and nice people!

Report this post to a moderator

Generally datagrams refer to UDP, and segments refer to TCP. As far as why the numbers are different, I can't explain that.

Report this post to a moderator

A segment is the PDU this is formed at the Transport layer when the data stream is segmented. This is then pasted down to the Network layer where the segment is encapsulated in a datagram (packet) this contains logical address information etc used for routing the packet (datagram) to the remote network. This is then passed down to the Data Link layer where the datagram is framed with information which includes physical addressing (MAC addresses). Finally the frame is passed down to the physical layer where it is broken down into bits ready to be placed on the physical network.

There is loads of info I've left out but that is a very basic look from segments to bits etc.

From all my studying the terms packet and datagram have been used interchangeably.

As for the difference in datagram's in to datagram's out. This is to do with the way TCP/IP works. You request a web page with only a few datagram's (three way handshake) and then the web server will send say four datagram's and your PC will send 1 acknowledgement that those four datagram's were received. So your receiving four times more datagram's than your sending. This is why most cable and xDSL connections are asynchronous as you normally receive more data (download) than you send (upload).

Sorry I got a bit carried away there.

__________________
There are only 10 kinds of people in the world, those who understand binary and those who don't!

Last edited by Tronn on 01-27-03 at 10:33 PM

Report this post to a moderator

Mmmm....so, according to your explanation, Datagrams sent and received must have to be the same, right?


Let' see my own case again. These are the numbers showed by my Neteork Monitor:

(IP)Datagramas received: 13257
(IP)Datagrams sent: 13257

(UDP)Datagrams In: 4790
(UDP)Datagrams Out: 5203

(TCP)Segments Received: 8378
(TCP)Segments Sent: 9046

__________________
Best Regards
José A. Campo
MCSA, Net+, A+, CST



Colombia: flowers, rivers, oceans, soccer...and nice people!

Last edited by jocampo on 01-27-03 at 11:40 PM

Report this post to a moderator

No. As your a client machine you should find that you have received more datagrams than you have sent.

__________________
There are only 10 kinds of people in the world, those who understand binary and those who don't!

Report this post to a moderator

quote:

---

Originally posted by Tronn
No. As your a client machine you should find that you have received more datagrams than you have sent.

---

Hi.

Check my post again, i edited it...


Well!!!!! i think i recall now, Segments received must be less than Sent because the 3 way handshake SYN process, right?....ok...i see ....but what about the IP values of Datagrams Send and Received? they have to be the same if there are no problems on the network?

__________________
Best Regards
José A. Campo
MCSA, Net+, A+, CST



Colombia: flowers, rivers, oceans, soccer...and nice people!

Last edited by jocampo on 01-27-03 at 11:46 PM

Report this post to a moderator

quote:

---

Originally posted by jocampo
Hi.

Check my post again, i edited it...


Well!!!!! i think i recall now, Segments received must be less than Sent because the 3 way handshake SYN process, right?....ok...i see ....but what about the IP values of Datagrams Send and Received? they have to be the same if there are no problems on the network?

---

Also, depending on the sliding window size, you only send one ACK datagram for every 3 or 4 datagrams received.

As for your IP figures. I'm not really sure what that's measuring. Again I would have thought that amount sent would be less than the amount received.

Anybody else?

__________________
There are only 10 kinds of people in the world, those who understand binary and those who don't!

Report this post to a moderator

(IP)Datagramas received: 13257
(IP)Datagrams sent: 13257

(UDP)Datagrams In: 4790
(UDP)Datagrams Out: 5203

(TCP)Segments Received: 8378
(TCP)Segments Sent: 9046

Can someone please explain these values to me? They are taken from my Internet connection. why some of 'em are identicals...why some not......etc.... nobody??

__________________
Best Regards
José A. Campo
MCSA, Net+, A+, CST



Colombia: flowers, rivers, oceans, soccer...and nice people!

Report this post to a moderator

"From all my studying the terms packet and datagram have been used interchangeably."

A datagram is a data packet that has had the network address added to it during the ecapsulation process.

A packet is a group of bits which encompasses a header, data, and trailer.

Report this post to a moderator

quote:

---

Originally posted by cutshaw
"From all my studying the terms packet and datagram have been used interchangeably."

A datagram is a data packet that has had the network address added to it during the ecapsulation process.

A packet is a group of bits which encompasses a header, data, and trailer.

---

__________________
There are only 10 kinds of people in the world, those who understand binary and those who don't!

Report this post to a moderator