Sub-IP Mesh for LoWPAN

Nandu Kushalnagar & Gabriel Montenegro

LoWPAN Considerations

• Adhoc multi hop meshing– Proactive routing– Reactive routing

• Routing – Above IP (Orthogonally possible)– Sub-IP (Allows efficient header compression, smaller route

tables)

• Flexible routing metric– Costs instead of hop Count (Allows better metrics)

• Low routing overhead (much lower than traditional networks)

• Reuse existing specs

Reactive routing Sub-IP

• Suggest simplifications to AODV(RFC 3561), AODVbis and DYMO

(draft-montenegro-lowpan-aodv-00.txt under works)

– Use 64 bit/16 bit addresses instead of IP addresses– Use prot_type field to indicate AODV control

messages instead of UDP ports– Only final destination responds to RREQ– Hello messages are not used, instead use 802.15.4

link layer mechanisms such as ACKs, beacon responses, overhearing packets, etc

• Suggest this be separate from the original IP over 802.15.4 spec

Future potential sub-IP routing

• OLSR, DYMO, DSR?

Backup

Proactive routing below IP

• Suggest simplifications to OLSR (RFC 3626)– Use 64 bit/16 bit addresses instead of IP

addresses– Use prot_type field to indicate OLSR control

messages instead of UDP ports– MID messages are not used– HTime to be made large to alleviate overhead

of hello messages– Omission of OLSR auxiliary functionality