1 Types of Point to Point Protocols l SLIP over async –Very simple –IP only –Unreliable - no checksum l HDLC over sync –various proprietary versions –frames have checksum l PPP

2 PPP l “SLIP done right” l Used for synchronous and asynchronous transmission l Extended negotiation mechanism l Multiple protocol support

3 PPP and OSI model Synchronous or Asynchronous Physical Media LCP - Link Control Protocol PPP Network Control Protocol IPCP IPXCP others Physical Layer Data Link Layer Network Layer

4 LCP Configuration Options

5 PAP/CHAP l PAP –Password required –Unencrypted password sent via the link –Allows storage of encrypted passwords l CHAP –Challenge handshake –No passwords sent via the link –Need for storing unencrypted secrets

6 Multilink PPP l Combining physical links into one logical bundle l Result: higher speed and lower latency l MPPP / Bonding –MPPP assembles/disassembles frames on the Data Link Layer –MPPP used for synchronous and asynchronous physical links –Bonding assembles/disassembles on the bit level