Very Computer

What is the difference between PPP and SLIP.  I understand that PPP is
suppose to be much better, in what ways?  If you are calling a site using
SLIP, can you change to PPP without the other end changing?  I understand
Morningstar makes a PPP package which I received some information on, but
I still am not clear on the differences, advantages, and useage, could
someone help me out?

Thanks.

Steve

--
  Steven E. Frazier
 DID: (614) 761-6612
VNET:       424-6612
 FAX: (614) 761-6679

   What is the difference between PPP and SLIP.  

The first thing you'll notice is that their RFCs are numbered
differently - 1055 vs 1171 :-) Also, while SLIP describes itself as a
"non-standard", PPP is the product of the Internet Engineering Task
Force PPP Working Group and is on track to being a "blessed" Internet
Standard.

Read the RFCs for a description of their respective protocols.  SLIP
is a starkly minimalist approach, only suggesting what byte to prepend
and perhaps append to each frame sent across the wire.  PPP addresses
a lot of other issues too.

   I understand that PPP is suppose to be much better, in what ways?

Read the Deficiencies section of RFC-1055 and the Introduction of
RFC-1171 for a definitive discussion.  SLIP was a "first cut", from
which the IETF PPP Working Group learned plenty.  PPP is a more
general solution to the problem.

The most obvious differences that I can think of off the top of my
head:
        PPP incorporates FCS error checking.  SLIP expects higher
        levels of the protocol stack to worry about that sort of
        stuff.

        PPP allows different implementations to agree on a set of
        mutually-acceptable features (what protocol family to carry,
        various compression techniques, frame size (MTU/MRU),
        addresses of both ends, etc.) at connection time.  SLIP only
        carries IP, needs to know in advance whether to use TCP header
        compression and what frame size to use, and needs to know in
        advance what addresses are at each end of the link.

        PPP can negotiate a truly huge frame size, though a MTU of
        1500 seems to be a common compromise between batch throughput
        and interactive responsiveness.  SLIP can send any size that
        both implementations can support, and while the RFC suggests
        1006, many (most?) use 256.

        PPP can be used in either asynchronous or synchronous
        environments.  It has become the standard protocol for
        high-speed routers to talk over leased lines, at speeds up to
        T1.  This allows people to build networks using routers from
        different vendors, and expect them to all work together.

   If you are calling a site using SLIP, can you change to PPP without
   the other end changing?

No, the two use different framing techniques.  PPP is not upward
compatible from SLIP, though some hosts or routers may contain
implementations of both.

Is there any sites where these RFC's are stored?  Anonymous FTP sites of
course.  Thanks in advance for the Info.....

Raghu

--------------------------------------------------------------
Standard Disclaimer

|> Is there any sites where these RFC's are stored?  Anonymous FTP sites of
|> course.  Thanks in advance for the Info.....

They're on uunet.uu.net.  Also, quoting from RFC-INDEX.TXT:

Many RFCs are available online; if not, this is indicated by (Not online).
Paper copies of all RFCs are available from the NIC, either individually

Online copies are available via FTP or Kermit from NIC.DDN.MIL as
RFC:RFC####.TXT or RFC:RFC####.PS (#### is the RFC number without leading
zeroes).

Additionally, RFCs may be requested through electronic mail from the

with a subject line of "RFC ####" for text versions or a subject line
of "RFC ####.PS" for PostScript versions.  To obtain the RFC index,
the subject line of your message should read "RFC index".

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