Implementation of SNMP Protocol with ContikiOS [Kur10] for WSN430 targets

Transcription

1 Implementation of Protocol with ContikiOS [Kur10] for WSN430 targets Équipe MADYNES, INRIA 31/03/2011

2 Mgmt of 6LowPAN Networks [JS10] Why 6LoWPAN Management? Do autonomiclow-poweredconstrained devices need management? Example Mgmt questions : Data in the nodes (energy left, sensors data,...) Key management Detecting failures in 6LowPAN Siarhei Kuryla Jürgen Schönwälder. Management of 6lowpan networks, Siarhei Kuryla. contiki-snmp,

3 IEEE /6LoWPAN/IPv6/... Protocol Stack

4 6LowPAN facts [JS10] Motivation of IP over (RFC 4919) IP-based technologies already exist and work eciently. Open and free specications Vs closed proprietary solutions. No need for translation gateways or proxies. overview 6LowPAN aim : transmit IPv6 packets more eciently over IEEE LowPAN mechanism : Can use in unslotted CSMA/CA mode (or beacons for link-layer device discovery) fragmentation/reassembly header compression mesh routing support (mesh under) Ongoing IETF work dealing with routing, neighbour discovery, and stateful compression schemes

5 / 6LowPAN Prototype Targeted Hardware WSN430 : MSP430F bit Ultra-Low-Power MCU 48kB Flash 10kB RAM RF CC1101 (Sub-1 GHz RF Transceiver) Sensors Light (TSL2550) Temperature external (DS1722) & cpu Temperature sensor Microphone 1MB external memory (M25P80) OS latest 2.x, Senslab (2.5 rc1)

6 Overview [JS10] General features messages up to 484-byte length v1 and v3 message processing models USM security model : HMAC-MD5-96 authentication protocol CFB128-AES-128 symmetric encryption protocol MIB API to dene and congure accessible managed objects : Get, GetNext, Set supported scalar and tabular MIB objects are supported number of rows of a tabular object can be changed at runtime add_scalar (oid, value type, default value, ags, get fn=null, set fn=null) add_table (oid, get fn, get-next-oid fn, set fn=null)

7 WSN430 specic MIB Modules implemented v2-mib system information IF-MIB network interface information ENTITY-SENSOR-MIB sensors data MIB API and WSN430 Clock functionality MAC IF-MIB statistics : cc1100-radio.c (receiving stats) frame c (sending stats) Rows in ENTITY-SENSOR-MIB : battery-sensor temperature-sensor (cpu) light-sensor, shares usart-0 port with serial

8 ROM Memory Usage From.map le Figure: Binary map of our application documentation/gallery/treemap.html

9 Issues Only v1 tested due to memory footprint (v3 : +22kB) Theoretical MTU of 1280 bytes : No packets larger than 100 bytes are successfully received Large responses or multiple variable bindings ( Table Views) fail It goes up to 192 bytes with udp-server and client example with real wsn430 targets 192 bytes with Wsim/Wsnet2 simulation 64 bytes with Cooja simulator Fragmentation is not ecient Low performances and no robustness of the gateway

10 Response latency Figure: Time delays performances with avr-raven platform[js10], then wsn430

11 Mgmt in resource constrained networks Short-term : RPL-MIB (draft) 6LowPAN-MIB (draft) Fragmentation and performances problems Mid-term : Graphic Manager Location algorithm Long-term : CoAP NETCONF over CoAP Piggy-backing of sensors status infos from RPL DIOs