l2r Submission September 2012 Geoff Mulligan, Proto6 Slide 1 Project: IEEE P Working Group for Wireless Personal Area Networks (WPANs) Submission Title: [Layer 2 Forwarding for Embedded IP] Date Submitted: [September 19, 2012] Source: [Geoff Mulligan] Company [ Proto6] Address [2175 Cloverdale Drive, Colorado Springs, CO 80920] Voice:[ ], FAX: [], Re: [] Abstract:[Motivation for Layer 2 Routing] Purpose:[This presentation is provided to help the discussion for L2R group] Notice:This document has been prepared to assist the IEEE P It is offered as a basis for discussion and is not binding on the contributing individual(s) or organization(s). The material in this document is subject to change in form and content after further study. The contributor(s) reserve(s) the right to add, amend or withdraw material contained herein. Release:The contributor acknowledges and accepts that this contribution becomes the property of IEEE and may be made publicly available by P

l2r Submission Layer 2 Forwarding for Embedded IP Geoff Mulligan 6LoWPAN WG Chair IPSO Alliance Chair

l2r Submission Problems with “Route Over” One subnet per node Breaks lots of things

l2r Submission Benefits of “Mesh Under” Maintains appearance of “ethernet like” network Things just work

l2r Submission IP over “Foo” Many RFCs describe how to adapt IP to specific media RFC 4944 and RFC 6282 describe adapting IPv6 to (2006) Required to make the media appear to be “ethernet like”

l2r Submission 6Lowpan is a mechanism to fit IPv6 into small data frames and improve transmission efficiency

l2r Submission

l2r Submission 6LoWPAN and 15.4 When started, we assumed that 6LoWPAN would sit on top of “ethernet like” service All nodes are one IP hop away Like ethernet and like Since there was no available IEEE standard we added support, in the form of a mesh header, to 6LoWPAN RFC 4919 defines the architecture of “forwarding at the link layer”

l2r Submission An Embedded Stack IEEE Physical Layer IEEE MAC layer 6LoWPAN IPv6 Application and other layers UDP / TCP SocketSNMP TFT P SE2.0 Routing ICMP Stack size < 20K RAM size < 4K Requires minimal MAC support Multiple Implementations – Open Source – Contiki/TOS – Atmel – Sensinode – Freescale – TI – ST Micro Layer 2 Forwarding

l2r Submission How 6LoWPAN works Stackable headers Stolen from IPv6 “Pay” only for what you use Only 3 bytes for compressed IPv6 header Only include mesh or fragmentation header if needed Extensible dispatch byte Defined in RFCs 4944 and 6282

l2r Submission 6LoWPAN compression X X XX X XX X

l2r Submission IPv6 Neighbor Discovery - Replaced ARP and DHCP (sort of) from IPv4 - Adds additional functionality - Stateless Address AutoConfiguration (SLAAC) - Router Identification - Duplicate Address Detection - Problems with ND for low bandwidth networks - Problems with 6lowpan ND

l2r Submission Why L2 Routing Simplifies higher layers – doesn't break IP Provides for hierarchical architecture Can better fit to idiosyncrasies of link Might provide improved performance Could provide more efficient multicast

l2r Submission Layer 2 in 802 IETF deals with the Internet Not networks or links Appears to be the most appropriate place

l2r Submission IETF Work 6Lowpan WG MANET ROLL CORE 6Man Ideas: SOLACE, LLN Futures, COMAN

l2r Submission Good Functionality Efficient multicasting Hierarchy of devices Multihop security

l2r Submission Issues Do we really need multicasting? Really, battery powered routers? Really? Rapid connectivity changes Wireless is not wired Are all nodes in the mesh in A IP subnet? Making use of 6lowpan mesh header What if we can't agree What functions of the MAC do we require (join)?

l2r Submission IEEE Layer 2 Forwarding If it was available we would have used it in 6LoWPAN When it is available we will use it.