🚀 go-pugleaf

Archive-name: ppp-faq/part2
Version: $Revision: 3.8 $
Last-modified: $Date: 93/12/14 14:55:32 $

   Read on here.
   
                              2. WHAT IS PPP?
                                     
       Introduction
      
       PPP features which may or may not be present
      
       PPP glossary
      
       PPP-relevant RFC's
      
2.1 Introduction

   PPP is the Internet Standard for transmission of IP packets over serial
   lines. PPP supports async and sync lines. For a general discussion of
   PPP, and of the PPP vs. SLIP question, look at the paper
   ftp.uu.net:vendor/MorningStar/papers/sug91-cheapIP.ps.Z (paper) and
   sug91-cheapIP.shar.Z (overhead projector slides)
   
2.2 PPP features which may or may not be present

   Above and beyond compatibility with basic PPP framing, note whether the
   software implements the following features.  Not all features are needed
   or even desired in every product. Please note also that not every free
   or commercial product description in this document has a complete list
   of all features includes.
   
  demand-dial             Bring up a PPP interface and dial the phone when
                          packets are queued for delivery; bring the
                         interface down after some   period of inactivity.
                         
   redial (For lack of a better term)
                          Bring up a PPP interface whenever it goes down,
                         to keep a line up.    (sometimes called camping)
                         
   camping (on a line)    see redial
                         
    scripting             Negotiate through a series of prompts or
                         intermediate   connections to bring up a PPP link,
                         much like the sequence of events   used to bring
                         up a UUCP link.
                         
   parallel               Configure several PPP lines to the same
                         destination and   do load sharing between them.
                         (Not standardized, usually only seen   in SLIP
                         implementations, noted there as "parallel-slip".)
                         
   filtering               Select which packets to send down a link or
                         whether to   bring up a "demand-dial" link based
                         on IP or TCP packet type or TOS,   e.g. don't dial
                         the phone for ICMP ping packets.
                         
   header compression     TCP header compression according to RFC1144.
                         Marginally useful on high speed lines, essential
                         for low speed lines.
                         
   server                 Accept incoming PPP connections, which might well
                         also   include doing the right things with
                         routing.
                         
   tunneling              Build a virtual network over a PPP link across a
                         TCP stream    through an existing IP network.
                         
   extra escaping         Byte-stuffing characters outside the negotiated
                         asyncmap, configurable in advance but not
                         negotiable.
                         
2.3 PPP glossary

   Every new technology breeds its own set of acronyms.  PPP is no
   different.  Here is a glossary of sorts.
   
ack                     Acknowledgement.
AO                      Active open [state diagram] (no lonter part of the
                        FSM as of RFC1331)
C                       Close [state diagram]
CHAP                    Challenge-Handshake Authentication Protocol
                        (RFC1334)
D                       Lower layer down [state diagram]
DES                     Data Encryption Standard
DNA                     Digital Network Architecture
IETF                    Internet Engineering Task Force.
IP                      Internet Protocol
IPCP                    IP Control Protocol.
IPX                     Internetwork Packet Exchange (Novell's networking
                        stack)
FCS                     Frame Check Sequence [X.25]
FSA                     Finite State Automaton
FSM                     Finite State Maschine
LCP                     Link Control Protocol.
LQR                     Link Quality Report.
MD4                     MD4 digital signature algorithm
MD5                     MD5 digital signature algorithm
MRU                     Maximum Receive Unit
MTU                     Maximum Transmission Unit
nak                     Negative Acknowledgement
NCP                     Network Control Protocol.
NRZ                     Non-Return to Zero bit encoding. (SYNC ppp default
                        because of
                        availability)
NRZI                    Non-Return to Zero Inverted bit encoding. (SYNC ppp
                        preferred
                        alternative to NRZ)
OSI                     Open Systems Interconnect
PAP                     Password Authentication Protocol (RFC1334)
PDU                     Protocol Data Unit (i.e., packet)
PO                      Passive open [no longer part of state diagram]
PPP                     Point to Point Protocol (RFC1331,
                        1332,
                        1333,
                        1334,
                        1362,
                        1376,
                        1377,
                        1378)
RCA                     Receive Configure-Ack [state diagram]
RCJ                     Receive Code-Reject [state diagram]
RCN                     Receive Configure-Nak or -Reject [state diagram]
RCR+                    Receive good Configure-Request [state diagram]
RER                     Receive Echo-Request [no longer part of state
                        diagram]
RFC                     Request for Comments (internet standard)
RTA                     Receive Terminate-Ack [state diagram]
RTR                     Receive Terminate-Request [state diagram]
RUC                     Receive unknown code [state diagram]
sca                     Send Configure-Ack [state diagram]
scj                     Send Code-Reject [state diagram]
scn                     Send Configure-Nak or -Reject [state diagram]
scr                     Send Configure-Request [state diagram]
ser                     Send Echo-Reply [no longer part of state diagram]
sta                     Send Terminate-Ack [state diagram]
str                     Send Terminate-Request [state diagram]
ST-II                   Stream Protocol
TO+                     Timeout with counter > 0 [state diagram]
TO-                     Timeout with counter expired [state diagram]
VJ                      Van Jacobson (RFC1144 header compression algorithm)
XNS                     Xerox Network Services
                        
2.4 PPP relevant RFCs

   Here's a list with descriptions.  Note some of these are obsolete. You
   might also want to  search for recent RFCs or  internet drafts in an
   up-to-date  RFC archive.
   
1378                      PPP AppleTalk Control Protocol (ATCP). Parker, B.
                         1992 November; 16 p.        (Format: TXT=28496
                        bytes)
1377                      PPP OSI Network Layer Control Protocol (OSINLCP).
                        Katz, D.  1992        November; 10 p. (Format:
                        TXT=22109 bytes)
1376                      PPP DECnet Phase IV Control Protocol (DNCP).
                        Senum, S.J.  1992 November;       6 p. (Format:
                        TXT=12448 bytes)
1362                      Allen, M.  Novell IPX Over Various WAN Media
                        (IPXWAN).  1992 September;       18 p. (Format:
                        TXT=30220 bytes)
1334                      PPP authentication protocols. Lloyd, B.; Simpson,
                        W.A.  1992 October;        16 p. (Format: TXT=33248
                        bytes)
1333                      PPP link quality monitoring. Simpson, W.A.  1992
                        May; 15 p. (Format:        TXT=29965 bytes)
1332                      PPP Internet Protocol Control Protocol (IPCP).
                        McGregor, G.  1992 May;        12 p. (Format:
                        TXT=17613 bytes)  (Obsoletes RFC1172)
1331                      Point-to-Point Protocol (PPP) for the
                        transmission of multi-protocol        datagrams
                        over point-to-point links. Simpson, W.A.  1992 May;
                        66 p.        (Format:
                        TXT=129892 bytes)  (Obsoletes RFC1171,
                        RFC1172)
1220                      Point-to-Point Protocol extensions for bridging.
                        Baker, F.,ed.  1991        April; 18 p. (Format:
                        TXT=38165 bytes)
1172                      Point-to-Point Protocol (PPP) initial
                        configuration options. Perkins,        D.; Hobby,
                        R.  1990 July; 38 p. (Format: TXT=76132 bytes)
                        (Obsoleted by       RFC1331, RFC1332)
1171                      Point-to-Point Protocol for the transmission of
                        multi-protocol datagrams       over Point-to-Point
                        links. Perkins, D.  1990 July; 48 p. (Format:
                         TXT=92321 bytes)  (Obsoletes RFC1134; Obsoleted by
                        RFC1331)
1134                      Point-to-Point Protocol: A proposal for
                        multi-protocol transmission of        datagrams
                        over Point-to-Point links. Perkins, D.  1989
                        November; 38 p.        (Format: TXT=87352 bytes)
                        (Obsoleted by RFC1171)
1144                     Compressing TCP/IP headers for low-speed serial
                        links. Jacobson, V.         1990 February; 43 p.
                        (Format: TXT=120959 PS=534729 bytes)
                        
   In comp.protocols.ppp (Message-ID:
   <BOB.92Dec3145948@volitans.MorningStar.Com>)
   
                                      bob@MorningStar.Com (Bob Sutterfield)
                                                                           
   wrote :
   
    All of 1134, 1171, and 1172 (and 1055, for that matter :-) have been
   obsoleted.  They're interesting only if you want to debug a connection
   with an ancient PPP implementation, and you're wondering why (e.g.) it
   asked you for IPCP option 2 with a length of only 4, and
   Compression-Type 0x0037.
   
    (There's a lot of that still running around - be careful out there.)
   
   *** Go back here.  To the top page here. Read on here.
   
   
-- 
-- 
	Ignatios Souvatzis
-
Solaris 2.1:  it's slow, needs 200M of disk space and comes without C compiler,
which makes it remarkably close to MS-Windows. oleg@gd.cs.csufresno.edu