<DIV id=RTEContent><BR><BR><B><I>Zhani Mohamed Faten <zhani_med_faten@yahoo.fr></I></B> a écrit : <BLOCKQUOTE class=replbq style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #1010ff 2px solid">Date: Tue, 6 Dec 2005 01:19:08 +0100 (CET)<BR>De: Zhani Mohamed Faten <zhani_med_faten@yahoo.fr><BR>Objet: RE: [e2e] TCP fragmentation and reassembly<BR>À: Erwin Davis <erwin.davis@gmail.com><BR><BR> <DIV id=RTEContent> </DIV> <DIV>hi</DIV> <DIV>the TCP header contain all information needed for reassambling paquet; these are the important fields :</DIV> <DIV> <DIV v:shape="_x0000_s1026"> <DIV class=O style="mso-line-spacing: '90 20 0'; mso-margin-left-alt: 216; mso-char-wrap: 1; mso-kinsoku-overflow: 1"><SPAN style="FONT-SIZE: 133%"><SPAN style="LEFT: -4.23%; POSITION: absolute; mso-special-format: bullet"></SPAN></SPAN><SPAN style="FONT-SIZE: 24pt; mso-bidi-font-family: Arial; mso-hansi-font-family: Arial"><FONT size=1>ID (16 bits): used to
identify datagram (the same for all fragments of one original datagram)</FONT></SPAN></DIV> <DIV class=O1 style="mso-line-spacing: '90 20 0'; mso-margin-left-alt: 468; mso-char-wrap: 1; mso-kinsoku-overflow: 1"><SPAN style="FONT-SIZE: 111%"><SPAN style="LEFT: -3.11%; POSITION: absolute; mso-special-format: bullet"><FONT size=1></FONT></SPAN></SPAN><FONT size=1> </FONT></DIV></DIV></DIV> <DIV> </DIV> <DIV v:shape="_x0000_s1026"> <DIV class=O style="mso-line-spacing: '90 20 0'; mso-margin-left-alt: 216; mso-char-wrap: 1; mso-kinsoku-overflow: 1"><SPAN style="FONT-SIZE: 133%"><SPAN style="LEFT: -5.07%; POSITION: absolute; mso-special-format: bullet"></SPAN></SPAN><SPAN style="FONT-SIZE: 24pt; mso-bidi-font-family: Arial; mso-hansi-font-family: Arial"><FONT size=1>the Flag in the TCP header means :</FONT></SPAN></DIV> <DIV class=O1 style="mso-line-spacing: '90 20 0'; mso-margin-left-alt: 468; mso-char-wrap: 1; mso-kinsoku-overflow: 1"><SPAN style="FONT-SIZE: 111%"><SPAN
style="LEFT: -4.35%; POSITION: absolute; mso-special-format: bullet"><FONT size=1></FONT></SPAN></SPAN><SPAN style="FONT-SIZE: 20pt; mso-bidi-font-family: Arial; mso-hansi-font-family: Arial"><FONT size=1>001: there is more fragments</FONT></SPAN></DIV> <DIV class=O1 style="mso-line-spacing: '90 20 0'; mso-margin-left-alt: 468; mso-char-wrap: 1; mso-kinsoku-overflow: 1"><SPAN style="FONT-SIZE: 111%"><SPAN style="LEFT: -4.35%; POSITION: absolute; mso-special-format: bullet"><FONT size=1></FONT></SPAN></SPAN><SPAN style="FONT-SIZE: 20pt; mso-bidi-font-family: Arial; mso-hansi-font-family: Arial"><FONT size=1>000: this the last fragment</FONT></SPAN></DIV><SPAN style="FONT-SIZE: 111%"> <DIV class=O1 style="mso-line-spacing: '90 20 0'; mso-margin-left-alt: 468; mso-char-wrap: 1; mso-kinsoku-overflow: 1"><SPAN style="LEFT: -4.35%; POSITION: absolute; mso-special-format: bullet"><FONT size=1></FONT></SPAN></SPAN><SPAN style="FONT-SIZE: 20pt; mso-bidi-font-family: Arial;
mso-hansi-font-family: Arial"><FONT size=1>O1X: do not fragment</FONT></SPAN></DIV> <DIV class=O1 style="mso-line-spacing: '90 20 0'; mso-margin-left-alt: 468; mso-char-wrap: 1; mso-kinsoku-overflow: 1"><SPAN style="FONT-SIZE: 20pt; mso-bidi-font-family: Arial; mso-hansi-font-family: Arial"><FONT size=1></FONT></SPAN> </DIV> <DIV class=O1 style="mso-line-spacing: '90 20 0'; mso-margin-left-alt: 468; mso-char-wrap: 1; mso-kinsoku-overflow: 1"><SPAN style="FONT-SIZE: 20pt; mso-bidi-font-family: Arial; mso-hansi-font-family: Arial"><FONT size=1>the <SPAN style="FONT-SIZE: 133%"><SPAN style="LEFT: -4.71%; POSITION: absolute; mso-special-format: bullet"><FONT size=1></FONT></SPAN></SPAN><SPAN style="FONT-SIZE: 24pt; mso-bidi-font-family: Arial; mso-hansi-font-family: Arial"><FONT size=1>FO (15 bit ): Fragment offset : means the </FONT></SPAN><SPAN style="FONT-SIZE: 111%"><SPAN style="LEFT: -4%; POSITION: absolute; mso-special-format: bullet"><FONT
size=1></FONT></SPAN></SPAN><SPAN style="FONT-SIZE: 20pt; mso-bidi-font-family: Arial; mso-hansi-font-family: Arial"><FONT size=1>Position of the fragment in the original datagramme . </FONT></SPAN> <DIV v:shape="_x0000_s1026"> <DIV class=O1 style="mso-line-spacing: '90 20 0'; mso-margin-left-alt: 468; mso-char-wrap: 1; mso-kinsoku-overflow: 1"><SPAN style="FONT-SIZE: 111%"><SPAN style="LEFT: -4.04%; POSITION: absolute; mso-special-format: bullet"><FONT size=1></FONT></SPAN></SPAN><SPAN style="FONT-SIZE: 20pt; mso-bidi-font-family: Arial; mso-hansi-font-family: Arial"><FONT size=1><SPAN style="mso-spacerun: yes">it is null for the first </SPAN>fragment = O</FONT></SPAN></DIV> <DIV class=O style="mso-line-spacing: '90 50 0'; mso-margin-left-alt: 216; mso-char-wrap: 1; mso-kinsoku-overflow: 1"></DIV></DIV></FONT></SPAN></DIV> <DIV class=O style="mso-line-spacing: '90 50 0'; mso-margin-left-alt: 216; mso-char-wrap: 1; mso-kinsoku-overflow: 1"></DIV></DIV>
<DIV>using these filds TCP can reassemble paquets<BR><BR><B><I>Erwin Davis <erwin.davis@gmail.com></I></B> a écrit :</DIV> <BLOCKQUOTE class=replbq style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #1010ff 2px solid">Helllo,<BR><BR>Packet from application layer may be framed in TCP layer based on MSS (maximum segment size, not MTU in IP layer) negotiated between two TCP layers of the end parties. My question is if the TCP layer in receiving side will reassemble the TCP fragments before it forward the packet to the application layer. If yes, then how the TCP layer in receiving side knows how many TCP fragments are made up for this one application packet. If not, will it require the intelligence from the application layer for the application packet reassembly. Thanks for your help,<BR><BR>erwin<BR></BLOCKQUOTE> <DIV><BR></DIV> <div> <HR SIZE=1> <B><FONT color=#ff0000>Appel audio GRATUIT</FONT> partout dans le monde</B> avec le nouveau Yahoo! Messenger<BR><A
href="http://us.rd.yahoo.com/messenger/mail_taglines/default/*http://fr.messenger.yahoo.com">Téléchargez le ici !</A> </BLOCKQUOTE><BR></DIV><p>
<hr size=1>
<b><font color=#FF0000>Appel audio GRATUIT</font> partout dans le monde</b> avec le nouveau Yahoo! Messenger<br>
<a href="http://us.rd.yahoo.com/messenger/mail_taglines/default/*http://fr.messenger.yahoo.com">Téléchargez le ici !</a>