PPP

Making Sense of Broadband networks: PPPoE Explained

A bit of background First .. PPPoE stands for Point to Point over Ethernet and is the successor of PPPoA. PPPoE is simply a method of encapsulating PPP packets into Ethernet frames. The standard is defined in RFC2516 . IPoE is growing very quickly but as far as I can tell PPPoE is still very widely deployed model in broadband networks. PPP protocol is a very mature protocol that was originally implemented to create and maintain direct connections between two nodes. PPP is such a protocol that provides many features but the one that is most interesting to broadband providers is the ability …

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Making sense of Broadband networks – Part 1

Broadband is a hot topic in the telecommunications industry nowadays; it is becoming the bread and butter for so many service providers and mobile carriers with the big growth and penetration rates in these technologies in the recent years.  ( Check this report about the EOCD countries). Although it is that important, broadband topics probably are not covered in any certification/education track and the reason might be that there is no “one shop suits all” in this field as in routing and switching technologies. In this post and others my aim is to provide some engineers with a brief but useful …

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How-to:Configure PPP authentication Part2 (CHAP)

The second and the most secure authentication method in PPP is CHAP. CHAP stands for challenge Handshake Authentication Protocol. How CHAP works? If CHAP is negotiated successfully during the LCP phase, the authenticator sends a challenge message to the peer. The peer responds to the challenge with a value calculated through an MD5 function. The authenticator then verifies the received value against its own calculated value. If they match the authentication is successful. In our example R1 is the authenticator and R2 is the authenticated peer. R1 will send a challenge to R2; R2 will calculate a response to the …

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How-to: Configure PPP authentication Part1 (PAP)

PPP has two different authentication methods, in today’s post we are going to explore the first method which is PAP. PAP stands for Password Authentication Protocol which is a simple authentication method. PAP is considered an insecure method because the password is sent in clear text format over the PPP link and has no protection to replay and brute force attacks. How PAP works? During the LCP phase both ends can negotiate the use of specific authentication protocol; if it was successful and LCP is completed a series of authentication messages are exchanged to identify the remote end. In our …

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PPP in brief

The Point-to-Point Protocol (PPP) provides a standard method for transporting multi-protocol packets over point-to-point links between two peers. In order to establish a communication link between two peers, each end of the PPP link must first send LCP packets to configure and test the data link. After the link has been established, the peer may be authenticated (optional). Then, PPP must send NCP packets to choose and configure one or more network-layer protocols. Once each of the chosen network-layer protocols has been configured, datagrams from each network-layer protocol can be sent over the link. The link will remain configured for …

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