Point to Point Protocols

1
Point to Point Protocols

• Ksenija Furman Jug
• ARNES
• ksenija.furman_at_arnes.si

2
Types of Point to Point Protocols

• SLIP over async
• Very simple
• IP only
• Unreliable - no checksum
• HDLC over sync
• various proprietary versions
• frames have checksum
• PPP

3
PPP

• SLIP done right
• Used for synchronous and asynchronous
  transmission
• Extended negotiation mechanism
• Multiple protocol support

4
PPP and OSI model
Network Layer
IPCP IPXCP others
PPP
Network Control Programs
Data Link Layer
LCP - Link Control Protocol
Synchronous or Asynchronous Physical Media
Physical Layer
5
LCP Configuration Options
6
PAP/CHAP

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

7
Multilink PPP

• Combining physical links into one logical bundle
• Result higher speed and lower latency
• 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