06 PPP
Description
This article is from the Amiga Networking FAQ, by Richard Norman with numerous contributions by others.
06 PPP
PPP Point to Point Protocol
For more info see:
RFC 1332, 1333, 1334, 1376, 1377, 1548, 1549,1552, and 1570.
PPP allows your computer to run TCP/IP over the serial port. This allows your computer to have a TCP/IP address. TCP/IP applications such as FTP can now use TCP/IP to deliver packets directly to your address. An analogy would be instead of having to go to the post office to get your mail, you now have a mailbox to which the postman can deliver your mail. In more technical terms you are no longer a terminal; you have become a node.
PPP is the committee-designed protocol which is supposed to be a sort of "universal" SLIP. It is intended to replace SLIP, while providing for all sorts of conditions, including the ability of use over non TCP/IP protocols. The two state machines in PPP are a real pain to implement. UNIX folks love it because a PPP implementation exists, and they pretty much type "MAKE" and it works.
PPP's good points:
- PPP users checksums (FCS) SLIP does not - PPP allows more than one protocol at a time, SLIP does not - PPP automatically negotiates IP addresses, SLIP does not - PPP can be used on non-transparent lines (e.g. when XON/XOFF is used by the modems), SLIP cannot
Several Amiga versions of PPP are in the works.
A shareware version called ppp.device by Holger Kruse has been released on Aminet Downloading "HowToUsePPP.lha" from Aminet probably wouldn't hurt either.
PPP is not a full protocol it fits in one of the layers between hardware and the TCP/IP protocol. It acts more like a device driver, but it is also a protocol because it is required at both ends of the physical link. PPP requires TCP/IP or similar protocol to talk to the applications.
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application layer: (AMosaic, telnet, ftp, etc.)
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protocol layer: (TCP/IP)
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*** SLIP or PPP ***
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hardware layer: (serial port)
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