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.
|
|
|
|
PPP Encryption Control Protocol (ECP) and Encryption Algorithms
(Page 2 of 4)
ECP Operation: Compression Setup
Like CCP, ECP is analogous to the
Network
Control Protocols (NCPs) that negotiate
parameters specific to a network layer protocol sent on the link, but
deals with how devices encrypt data rather than how they transport layer
three traffic. This also means that like the NCPs, ECP is a "lite" version
of LCP and works in the same basic way. Once an ECP link is negotiated,
encrypted frames can be sent between devices. When no longer needed,
the ECP link can be terminated.
ECP uses the same subset of seven
LCP message types that the NCPs use, and adds two more. The use of these
messages for each of the life stages of an ECP link is as
follows:
- Link Configuration: Like the NCPs (and
also like CCP of course), encryption configuration is done once ECP
reaches the Network-Layer Protocol phase. The process of setting
up encryption and negotiating parameters is accomplished using Configure-Request,
Configure-Ack, Configure-Nak and Configure-Reject
messages just as
described in the LCP topic, except the
configuration options are particular to ECP.
- Link Maintenance: Code-Reject messages
can be sent to indicate invalid code values in ECP frames. The two new
message types are Reset-Request and Reset-Ack, which are
used to reset the encryption (the ECP link) in the event of a detected
failure in decryption.
- Link Termination: An ECP link can be terminated
using Terminate-Request and Terminate-Ack. Again, remember
that like the NCP links, the ECP link is set up within an LCP link,
so closing it doesn't terminate the LCP link.
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! |
|
|
Home -
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.
|