6LoWPAN (Introduction, Problem Statement

1
6LoWPAN(Introduction, Problem Statement Goals)

• Nandakishore Kushalnagar
• Intel Corporation

2
(No Transcript)
3
(No Transcript)
4
Subtleties of IEEE 802.15.4

• Small packet size
• Max MAC frame size 127 bytes
• Max MAC payload 102 bytes
• With security (worst case) 81 bytes
• Uses 64 bit MAC addresses, but has provisions for
  16 bit short addresses
• Support for multiple topologies
• Supports AES block cypher in several modes
  (AES-CCM-64 authenticated encryption mandatory)
• Data rates from 20kbps to 250kbps
• Range from 10m to 30m

5
Other potential LoWPAN standards

• IEEE 802.15.3b a.k.a. UWB supporting higher bit
  rate emerging
• Maybe others ?

6
Goals of 6LoWPAN

• In all cases, when possible reuse existing
  protocols before creating new ones
• Address mismatch between MTU sizes of LoWPANs and
  IPv6
• Support stateless auto configuration of IPv6
  addressing (and perhaps other schemes like
  location-aware, etc)
• Specify header compression (use existing and/or
  new techniques such as header reconstruction,
  header short circuiting, etc)
• Define security model, mechanisms, configuration
  procedures and bootstrapping
• Specify network management (SNMP?)
• Specify routing suitable for LoWPAN networks
  (MANET?, topology aware, Below L3 and/or above
  L3?, etc)
• Specify methods to enable and disable IPv6 over
  LoWPAN.
• Specify hooks between L3 and higher layers?
• Specify lightweight discovery mechanisms
• Specify requirements and potential changes at L3
  and above (e.g., issues with reliable data
  transfer)
• Specify implementation considerations and best
  common practices of an IPv6 stack

7
Why IP?

• Most of the IP based technologies already exist,
  well known and proven to be working.
• The pervasive nature of IP networks allows use of
  existing infrastructure.
• Intellectual property conditions for IP
  networking technology is either more favorable or
  at least better understood than proprietary and
  newer solutions.

8
Why IPv6?

• Pros
• More suitable for higher density (futuristically
  2 orders of magnitude larger than traditional
  networks)
• Statelessness mandated
• No NAT necessary (adds extra cost to the cost
  prohibitive WSN)
• Possibility of adding innovative techniques such
  as location aware addressing
• IEEE 64 bit address subsumed into IPv6 address
• Cons
• Larger address width (Having efficient address
  compression schemes may alleviate this con)
• Complying to IPv6 node requirements (IPSec is
  mandated)

9
Why not IPv4?

• Limited address space
• Not as compressible
• NAT functionality needs gateways, etc leads to
  more cost
• Statelessness not mandated

10
Backup
11
Drafts of 6LoWPAN

• Define a shim layer below IP
• Fragmentation/Reassembly to satisfy IPv6 MTU of
  1280 bytes
• Routing including mesh
• Header compression mechanisms
• Header reconstruction for intra PAN communication
• Header short circuiting
• Header configuration to enable/disable IPv6
• Define a IPv6 LoWPAN Profile
• Address IPv6 node requirements
• Define
• L2/L3 interface mechanism
• Appropriate security services
• Routing considerations
• Network management with SNMP
• Implementation considerations
• Miscellaneous (may be subsequent drafts)
• Hooks from L3 for in network processing
  (especially critical for WSN)
• Transport layer (UDP / TCP)
• Security configuration