Please Whitelist This Site?
I know everyone hates ads. But please understand that I am providing premium content for free that takes hundreds of hours of time to research and write. I don't want to go to a pay-only model like some sites, but when more and more people block ads, I end up working for free. And I have a family to support, just like you. :)
If you like The TCP/IP Guide, please consider the download version. It's priced very economically and you can read all of it in a convenient format without ads.
If you want to use this site for free, I'd be grateful if you could add the site to the whitelist for Adblock. To do so, just open the Adblock menu and select "Disable on tcpipguide.com". Or go to the Tools menu and select "Adblock Plus Preferences...". Then click "Add Filter..." at the bottom, and add this string: "@@||tcpipguide.com^$document". Then just click OK.
Thanks for your understanding!
Sincerely, Charles Kozierok
Author and Publisher, The TCP/IP Guide
NOTE: Using software to mass-download the site degrades the server and is prohibited.
If you want to read The TCP/IP Guide offline, please consider licensing it. Thank you.
IP Datagram Size, Maximum Transmission Unit (MTU), Fragmentation and Reassembly
main responsibility is to deliver data between internetworked devices.
As we saw in the
preceding section, this requires that
data received from higher layers be encapsulated into IP datagrams for
transmission. These datagrams are then passed down to the data link
layer where they are sent over physical network links.
In order for this to work properly,
each datagram must be small enough to fit within the frame format of
the underlying technology. If the message is bigger than the maximum
frame size of the underlying network, it may be necessary to break up
an IP message into several datagrams, a process called fragmentation.
The datagrams are then sent individually and reassembled into
the original message.
The Internet Protocol is designed
to manage datagram size, and to allow fragmentation and reassembly in
a seamless manner. In this section I explore issues related to managing
the size of IP datagrams. I start with an overview of datagram size
issues and the important concept of a network's maximum transmission
unit (MTU), discussing why fragmentation is necessary. I then describe
the process by which IP messages to be transmitted are fragmented by
the source device and possibly routers along the path to the destination,
and then outline how they are reassembled by the recipient.
Background Information: Explaining fragmentation and reassembly requires some understanding of the basic format of IP datagrams and some of the fields they contain. If you haven't yet read the topic describing IP datagram general format you may wish to review it before proceeding here.
|If you find The TCP/IP Guide useful, please consider making a small Paypal donation to help the site, using one of the buttons below. You can also donate a custom amount using the far right button (not less than $1 please, or PayPal gets most/all of your money!) In lieu of a larger donation, you may wish to consider purchasing a download license of The TCP/IP Guide. Thanks for your support!|
Table Of Contents - Contact Us
The TCP/IP Guide (http://www.TCPIPGuide.com)
Version 3.0 - Version Date: September 20, 2005
© Copyright 2001-2005 Charles M. Kozierok. All Rights Reserved.
Not responsible for any loss resulting from the use of this site.