6TiSCH + RPL @ Telecom Bretagne 2014
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6TiSCH + RPL @ Telecom Bretagne 2014

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3 hours course on IEEE and IETF protocols introducing the 6TiSCH architecture and the RPL routing protocol. Course given at telecom Bretagne on Feb 12th 2014

3 hours course on IEEE and IETF protocols introducing the 6TiSCH architecture and the RPL routing protocol. Course given at telecom Bretagne on Feb 12th 2014

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  • So let’s take a look at the characteristics on an LLN. What is it that makes an LLNAs mentioned before the devices are highly constrained, so we need to keep the state in each device to a minimum – for example we would not want the entire Link State database in every SensorIt is critical than an LLN uses the minimum amount of energyThere is a various array of traffic patterns - multipoint and point2pointProbably the most important thing to note is LLNs operate over networks with very restricted frame sizesWe can’t have giant packets running over poor quality linksThe routing protocol has to be really efficient – we can’t have it catering for every event/situation possible.
  • Wespeak of iot but most of the time thisisreally about ITOT, thatis the integrationof OT and IT.Benefits of convergence. 40 yearsago, OT = OsTralia. In convergence isindustrialthat’scalled indus internet.Cheerscale => IPv6Evolution thatis happening. Eg HART-IP . Startingnaturally in the plant net, then control net thendevices. We are creating a cross fire to accelerate the adoption.130 millions ports, 25% Ethernet. Split of H1 (FF, wireless) and H2 (ethernet) fieldbuses .The convergence of IT and OT technologies, aka the Industrial Internet, represents a multibillion opportunity for IT vendors.Our strategy to promote that convergence includes pushing IPv6 to the industrial M2M endpoints to enable end-to-end connectivity over deterministic wireless networks that are being developed at IEEE to emulate the characteristics of incumbent OT networks This work will benefit IOTG (CIBU)IOTG has already started to incorporate partner solutions (1552S, 1552WU) but in a fragmented market. This project approach will converge and promote an international standard solution (IPv6, 6TiSCH, CoAP, 802.15.4e based). The project leverages standards to drive IPv6 at the endpoints (that we do not own), which in turn justifies the introduction of Cisco equipment in the factory
  • • Direct-sequence spread spectrum (DSSS) modulation technique - this makes the ISA100.11a signal look like noise to other wireless systems.• Spatial diversity - Two field access points receive transmission from the field instrument.• Frequency diversity - Frequency hopping over the available channels in the bandwidth of the device's transmitting frequency.• Dynamic power control - Reduces possible interference with other wireless networks.• Channel black listing and adaptive channel hopping - Avoids congested channels. • Implementation of IEEE 802.15.4-2006 - Proven to coexist in very congested environments. • Careful management of the ISA100.11a wireless network implementation.
  • RPL builds a routing topology in the form of a DAG – a Directed Acyclic Graph (tree vsDAGs)It is a distance vector protocol that is proactive – it can build alternate paths during topology setup – rather than reactive where we rely on control plane messages after the failure to figure out the alternate path DV was chosen because the size of a link state DB would be way too largeHistorically, a number of interesting research initiatives on routing in WSN,Main focus on algorithms … a bit less on architectureMost work assuming the use of MAC addresses – L2 “routing” (mesh-under)Support of multiple PHY/MAC is a MUST: IEEE 802.15.4, LP Wifi, PLC (number of flavors), …Now … if what you want is a layered architecture supporting multiple PHY/MAC, there aren’t that many options …IP !RPL has been designed for lossy links including PLC such as P1901.2, which are of the utmost important for example for AMI in Europe. Sincethese links do exhibit similar properties in terms of instability, BER, ... RPL is well suited for these networks too. I had to fight a bit when we first determineROLL's charter to make sure that non RF links such as PLC were part of the charter (strictly speaking we are independent of the L3 of course but this was to insist onthat decoupling and point out that RPL was a routing protocol for LLN). 
  • RPL builds a routing topology in the form of a DAG – a Directed Acyclic Graph (tree vsDAGs)It is a distance vector protocol that is proactive – it can build alternate paths during topology setup – rather than reactive where we rely on control plane messages after the failure to figure out the alternate path DV was chosen because the size of a link state DB would be way too largeHistorically, a number of interesting research initiatives on routing in WSN,Main focus on algorithms … a bit less on architectureMost work assuming the use of MAC addresses – L2 “routing” (mesh-under)Support of multiple PHY/MAC is a MUST: IEEE 802.15.4, LP Wifi, PLC (number of flavors), …Now … if what you want is a layered architecture supporting multiple PHY/MAC, there aren’t that many options …IP !RPL has been designed for lossy links including PLC such as P1901.2, which are of the utmost important for example for AMI in Europe. Sincethese links do exhibit similar properties in terms of instability, BER, ... RPL is well suited for these networks too. I had to fight a bit when we first determineROLL's charter to make sure that non RF links such as PLC were part of the charter (strictly speaking we are independent of the L3 of course but this was to insist onthat decoupling and point out that RPL was a routing protocol for LLN). 
  • A local RPLInstanceID is autoconfigured by the node that owns the DODAGID and it MUST be unique for that DODAGID. The DODAGID used to configure the local RPLInstanceID MUST be a reachable IPv6 address of the node, and MUST be used as an endpoint of all communications within that local instance.
  • RPL builds a routing topology in the form of a DAG – a Directed Acyclic Graph (tree vsDAGs)It is a distance vector protocol that is proactive – it can build alternate paths during topology setup – rather than reactive where we rely on control plane messages after the failure to figure out the alternate path DV was chosen because the size of a link state DB would be way too largeHistorically, a number of interesting research initiatives on routing in WSN,Main focus on algorithms … a bit less on architectureMost work assuming the use of MAC addresses – L2 “routing” (mesh-under)Support of multiple PHY/MAC is a MUST: IEEE 802.15.4, LP Wifi, PLC (number of flavors), …Now … if what you want is a layered architecture supporting multiple PHY/MAC, there aren’t that many options …IP !RPL has been designed for lossy links including PLC such as P1901.2, which are of the utmost important for example for AMI in Europe. Sincethese links do exhibit similar properties in terms of instability, BER, ... RPL is well suited for these networks too. I had to fight a bit when we first determineROLL's charter to make sure that non RF links such as PLC were part of the charter (strictly speaking we are independent of the L3 of course but this was to insist onthat decoupling and point out that RPL was a routing protocol for LLN). 

6TiSCH + RPL @ Telecom Bretagne 2014 6TiSCH + RPL @ Telecom Bretagne 2014 Presentation Transcript

  • • Telecom Bretagne, February 2014 © 2013-2014 Cisco and/or its affiliates. All rights reserved. Pascal Thubert Cisco Confidential 1
  • Challenge: harness innovation • More efficient operations • New and/or improved experience Shaking up the competitive landscape • Between small and large entities • Leveraging IT, data and analytics http://internetofeverything.cisco.com/explore © 2013-2014 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 2
  • 1000*scale => No leak in the Internet => Opaque Fringe operations Reachability => Radio Addressing => IPv6 Density => spatial reuse => Routing © 2013-2014 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 3
  • The Fringe of the Internet LLNs IEEE 802.15.4 IEEE 802.15.4e TSCH 6TiSCH © 2013-2014 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 4
  • Routing IP in LLNs Routing over radios RPL concepts Applying RPL © 2013-2014 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 5
  • The Fringe of the Internet BRKEWN-3012 © 2010 Cisco and/or its affiliates. All rights reserved. Unclassified 6
  • • The Internet • Fully engineered • Hierarchical, Aggregations, ASs, Wire links • Fully distributed States • Shows limits (BGP tables, addr. depletion) Reached adult size, mature to aging Conceptually unchanged by IPv6 • IPv4 Intranets Same structure as the Internet • Yet decoupled from the Internet • • NAT, Socks, Proxies First model for Internet extension © 2013-2014 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 7
  • L2 mesh Under A Multi-hop Public Access Points, Proprietary mission specific products Address the scale issue at L2/ND 4 3 2 Edge 1 L3 Route Over Migration to IETF Protocols (RPL) Internet of Things (IOT, M2M) Different IPv6 (6LoWPAN, SDN) NEMO A‟s Home B‟s Home Mobile Overlays Global reachability Route Projection Network virtualization Fixed wired Infrastructure 5 Mesh 6 7 8 B C © 2013-2014 Cisco and/or its affiliates. All rights reserved. MANET The Fringe DOES NOT LEAK into the Routing Infrastructure Cisco Confidential 8
  • Low Power Lossy Networks 9
  • New level of cost effectiveness Deploying wire is slow and costly Low incremental cost per device Reaching farther out New types of devices (Internet Of Things) New usages (widespread monitoring, IoE) Global Coverage from Near Field to Satellite via 3/4G © 2013-2014 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 10
  • • LLNs comprise a large number of highly constrained devices (smart objects) interconnected by predominantly wireless links of unpredictable quality • LLNs cover a wide scope of applications • Industrial Monitoring, Building Automation, Connected Home, Healthcare, Environmental Monitoring, Urban Sensor Networks, Energy Management, Asset Tracking, Refrigeration • Several IETF working groups and Industry Alliance addressing LLNs • IETF - CoRE, 6Lowpan, ROLL • Alliances - IP for Smart Objects Alliance (IPSO) World‟s smallest web server © 2013-2014 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 11
  • • LLNs operate with a hard, very small bound on state • LLNs are optimised for saving energy in the majority of cases • Traffic patterns can be MP2P, P2P and P2MP flows • Typically LLNs deployed over link layers with restricted frame-sizes • Minimise the time a packet is enroute (in the air/on the wire) hence the small frame size • The routing protocol for LLNs should be adapted for such links • LLN routing protocols must consider efficiency versus generality • LLN nodes are typically very conservative in resources © 2013-2014 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 12
  • IEEE 802.15.4 13
  • Initial activities focused on wearable devices “Personal Area Networks” Activities have proven to be much more diverse and varied •Data rates from Kb/s to Gb/s •Ranges from tens of metres up to a Kilometre •Frequencies from MHz to THz •Various applications not necessarily IP based Focus is on “specialty”, typically short range, communications •If it is wireless and not a LAN, MAN, RAN, or WAN, it http://www.ieee802.org/15/pub/TG4.html is IEEE 802.15to be Task Group 4 (TG4) Charter likely WPAN™ 802.15 (PAN) © 2013-2014 Cisco and/or its affiliates. All rights reserved. The only IEEE 802 Working Group with Cisco Confidential 14
  • 802.15.4 Amendments 802.11 Wireless LAN WiFi 802.11a/b/g/n/ah 802.15 Personal Area Network 802.15.1 Bluetooth 802.15.4c PHY for China 802.15.2 Co-existence 802.15.4d PHY for Japan 802.15.3 High Rate WPAN 802.15.4e MAC Enhancements 802.15.4 Low Rate WPAN 802.15.4f PHY for RFID 802.15.5 Mesh Networking 802.15.4g Smart Utility Networks 802.15.6 Body Area Networking TV White Space PHY 15.4 Study Group IEEE 802 LAN/MAN 802.16 Wireless Broadband Access 802.22 Wireless Regional Area Network 802.15.7 Visible Light Communications © 2013-2014 Cisco and/or its affiliates. All rights reserved. TSCH • Industrial strength • Minimised listening costs • Improved security • Improved link reliability • Support smart-grid networks • Up to 1 Km transmission • >100Kbps • Millions of fixed endpoints • Outdoor use • Larger frame size • PHY Amendment • Neighborhood Area Networks Cisco Confidential 15
  • • Designed for low bandwidth, low transmit power, small frame size • More limited than other WPAN technologies such as Bluetooth • Basic packet size is 127 bytes (802.15.4g is up to 2047 bytes) (Smaller packets, less errors) • Transmission Range varies (802.15.4g is up to 1km) • Fully acknowledged protocol for transfer reliability • Data rates of 851, 250, 100, 40 and 20 kbps (IEEE 802.15.4-2011 05-Sep-2011) • Frequency and coding dependent • Two addressing modes; 16-bit short (local allocation) and 64-bit IEEE (unique global) • Several frequency bands (Different PHYs) • Europe 868-868.8 MHz – 3 chans , USA 902-928 MHz – 30 chans, World 2400-2483.5 MHz – 16 chans • China - 314–316 MHz, 430–434 MHz, and 779–787 MHz Japan - 920 MHz • Security Modes: None, ACL only, Secured Mode (using AES-CCM mode) • 802.15.4e multiple modes including Time Synchronized Channel Hopping (TSCH) © 2013-2014 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 16
  • • Specifies PHY and MAC only • Medium Access Control Sub-Layer (MAC) • Responsible for reliable communication between two devices • Data framing and validation of RX frames • Device addressing • Channel access management • Device association/disassociation • Sending ACK frames • Physical Layer (PHY) • Provides bit stream air transmission • Activation/Deactivation of radio transceiver • Frequency channel tuning • Carrier sensing • Received signal strength indication (RSSI) • Link Quality Indicator (LQI) • Data coding and modulation, Error correction © 2013-2014 Cisco and/or its affiliates. All rights reserved. Upper Layers (Network & App) MAC Layer (MAC) Physical Layer (PHY) Cisco Confidential 17
  • R F R P • Full Function Device (FFD) R F • Can operate as a PAN co-ordinator (allocates local addresses, gateway to other PANs) • Can communicate with any other device (FFD or RFD) • Ability to relay messages (PAN co-ordinator) • Reduced Function Device (RFD) • Very simple device, modest resource requirements • Can only communicate with FFD • Intended for extremely simple applications © 2013-2014 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 18
  • Operates at Layer 2 • Star Topology • Mesh Topology R F F R R R F P • All devices communicate to PAN co-ordinator which uses mains power • Other devices can be battery/scavenger R R P F F • Cluster Tree F R F F R F P F R • Devices can communicate directly if within range R F R R • Higher layer protocols like RPL may create their own topology that do not follow 802.15.4 topologies Single PAN co-ordinator exists for all topologies © 2013-2014 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 19
  • IEEE 802.15.4e TimeSlotted Channel Hopping 20
  • • Better process optimization and more accurate predictive maintenance increase profit; 1% improvement in a refinery with a $1.5B annual profit leads to $40k/day ($15M/yr) more profit • Thus more and different sensors can be justified economically, if they can be connected • But wire buried in conduit has a high installation and maintenance cost, with long lead times to change, and is difficult to repair • The solution: wireless sensors in non-critical applications, designed for the industrial environment: temperature, corrosion, intrinsic safety, lack of power sources (particularly when there is no wire) • For critical control loops, use wireless control room links with controllers located in the field, possibly connected over local wiring © 2013-2014 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 21
  • Converging ICT and OT Operational technology (OT) is hardware and software that detects or causes a change through the direct monitoring and/or control of physical devices, processes and events in the enterprise. Convergence of IT and OT technologies, aka the Industrial Internet, represents a multibillion opportunity for IT vendors and long term job creation. Deterministic Wireless Networking is one of the key elements. For each „critical‟ wired measurement there are hundreds missing ones that could be addressed through wireless (Industrial Internet) Architecture and Standards are necessary for Industry adoption © 2013-2014 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 22
  • Industrial connected device growth WWAN: GSM – LTE © 2013-2014 Cisco and/or its affiliates. All rights reserved. WLAN: 802.11 WPAN: 802.15.4, ISA100.11a, WirelessHART Cisco Confidential 23
  • ISA100: Wireless Systems for Industrial Automation ISA100.11a industrial WSN • Wireless systems for industrial automation • Process control and related applications Leverages 802.15.4(e) + IPv6 • Link Local Join process • Global Address runtime • 6LoWPAN Header Compression • Yet specific routing and ND • Next: Backbone Router ISA100.15 backhaul © 2013-2014 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 24
  • IEEE 802.15.4e  Amendment to the 802.15.4-2006 MAC needed for the applications served by  802.15.4f PHY Amendment for Active RFID  802.15.4g PHY Amendment for Smart Utility Networks  initially for Industrial applications  (such as those addressed by wiHART and the ISA100.11a standards)  Security: support for secured ack  Low Energy MAC extension   Channel Hopping   Coordinated Sampled Listening (CSL) Not built-in, subject to vendor design. Open std work started with 6TSCH New Frame Types  Enhanced (secure) Acknowledgement (EACK)  Enhanced Beacon and Beacon Request (EB and EBR)  Optional Information Elements (IE) © 2013-2014 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 25
  • Channel Hopping : • retry around interference, • round robin strategy Time Slotted (or Synchronized) : • • • • Deterministic: Synchronized + Time formatted in SlotFrame(s) Tracks: below IP, can be orchestrated by a third party like virtual circuits Slotted: benefits of slotted aloha vs. aloha => reduce collisions Battery operation: if traffic profile is known, devices wake upon need © 2013-2014 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 26
  • Reliability through (all possible!) Code diversity Spatial diversity Code Division Multiplex Access Dynamic Power Control Network Coding (WIP) DAG routing topology + ARCs Frequency diversity Duo/Bi-casting (live-live) Channel hopping B/W listing Time Diversity ARQ + FEC (HARQ) © 2013-2014 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 27
  • • Schedule => direct trade-off between throughput, latency and power consumption. • A collision-free communication schedule is typical in industrial applications. • IEEE802.15.4e published April 2012. A B 16 channel offsets C E D F G e.g. 31 time slots (310ms) I H © 2013-2014 Cisco and/or its affiliates. All rights reserved. J Cisco Confidential 28
  • 29
  • Why IPv6 ? Going IP BRKEWN-3012 © 2010 Cisco and/or its affiliates. All rights reserved. Unclassified 30
  • Why IP ? Open Standards vs. proprietary • COTS* suppliers drive costs down but • Reliability, Availability and Security up IP abstraction vs. per MAC/App • 802.11, 802.15.4 (e), Sat, 3G, UWB • Keep L2 topology simple To Infinity and Beyond… But End-to-End. • No intermediate gateway, tunnel, middle boxes & other trick * Commercial, off-the-shelf © 2013-2014 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 31
  • Which IP version ? The current Internet comprises several billion devices Smart Objects will add tens of billions of additional devices IPv6 is the only viable way forward IPv4 Unallocated pool exhausted March 2011 ! RIPE NCC: Sept 2012; ARIN March 2015 (last /8) Things Mobile Fixed © 2013-2014 Cisco and/or its affiliates. All rights reserved. Tens of Billions Smart Objects 2~4 Billions Phones & cars 1~2 Billions PCs & servers Cisco Confidential 32
  • Application Core Constrained Restful Environments Charter to provide a framework for resourceoriented applications intended to run on constrained IP networks. General 6lo IPv6 over the TSCH mode of 802.15.4e Internet 6TiSCH Initial charter to produce an architecture, a minimal RPL operation over a static schedule and a data model to control the LLC (6top) Lightweight Implementation Guidance Ops and Mgmt LWIG Routing IETF ROLL Charter is to provide guidance in building minimal yet interoperable IP-capable devices for the most constrained environments. . Routing over Low Power Lossy Networks Charter focusses on routing issues for low power lossy networks. Security Reuse work done here where possible Transport © 2013-2014 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 33
  • Requirement for a new standard • Industrial requires standard-based products • Must support equivalent features as incumbent protocols • Must provide added value to justify migration • 6TiSCH value proposition • Design for same time-sensitive MAC (802.15.4e TSCH) • Direct IPv6 access to device (common network mgt) • RPL Distributed routing for scalability (for monitoring) • Large scale IPv6 subnet for mobility (50K +) © 2013-2014 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 34
  • Active IETF WG, 4 WG docs being adopted Define an Architecture that links it all together Align existing standards • (RPL, 6LoWPAN, PANA?, RSVP, PCEP, MPLS) over 802.15.4e TSCH Support Mix of centralized and distributed deterministic routing Design 6top sublayer for L3 interactions Open source implementations (openWSN…) Multiple companies and universities participating © 2013-2014 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 35
  • Management and Setup Discovery Pub/Sub Centralized route and track computation and installation Authentication for Network Access Wireless ND (NPD proxy) PCEP/PCC CoAP/DTLS TCP Distributed Distributed route and track route and track computation computation and installation and installation AAA 6LoWPAN ND RPL UDP ICMP Time Slot scheduling and track G-MPLS forwarding RSVP IPv6 6LoWPAN HC 6top IEEE 802.15.4e TSCH © 2013-2014 Cisco and/or its affiliates. All rights reserved. } Cisco Confidential 36
  • CoAP CoAP CoAP CoAP UDP UDP UDP UDP IPv6 IPv6 IPv6 IPv6 6LoWPAN-HC 6LoWPAN-HC 6LoWPAN-HC 6LoWPAN-HC 6top 6top 6top 6top 15.4e TSCH 15.4e TSCH 15.4e TSCH 15.4e TSCH 15.4 PHY 15.4 PHY 15.4 PHY 15.4 PHY A X Y U © 2013-2014 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 37
  • CoAP CoAP CoAP CoAP UDP UDP UDP UDP IPv6 IPv6 IPv6 IPv6 6LoWPAN-HC 6LoWPAN-HC 6LoWPAN-HC 6LoWPAN-HC 6top 6top 6top 6top 15.4e TSCH 15.4e TSCH 15.4e TSCH 15.4e TSCH 15.4 PHY 15.4 PHY 15.4 PHY 15.4 PHY A © 2013-2014 Cisco and/or its affiliates. All rights reserved. X Y U Cisco Confidential 38
  • CoAP CoAP CoAP CoAP UDP UDP UDP UDP IPv6 IPv6 IPv6 IPv6 6LoWPAN-HC 6LoWPAN-HC 6LoWPAN-HC 6LoWPAN-HC 6top 6top 6top 6top 15.4e TSCH 15.4e TSCH 15.4e TSCH 15.4e TSCH 15.4 PHY 15.4 PHY 15.4 PHY 15.4 PHY 15.4 PHY 15.4 PHY TSCH TSCH Multi-protocol Multi-protocol © 2013-2014 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 39
  • CoAP CoAP CoAP CoAP UDP UDP UDP UDP IPv6 1st IPv6 1stIPv6 IPv6 6LoWPAN-HC 6LoWPAN-HC Next 6LoWPAN-HC Next 6LoWPAN-HC 6top 6top 6top 6top 15.4e TSCH 15.4e TSCH 15.4e TSCH 15.4e TSCH 15.4 PHY 15.4 PHY 15.4 PHY 15.4 PHY A © 2013-2014 Cisco and/or its affiliates. All rights reserved. X Y U Cisco Confidential 40
  • Backbone Router intra/ Internet 6TiSCH LLN Backbone Attached LLN* 6TiSCH LLN PCE Virtual devices NMS * LLN == Low Power Lossy Network © 2013-2014 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 41
  • Common ND based abstraction over a backbone Scales DAD operations (distributes 6LoWPAN ND LBR) Scales the subnetwork (high speed backbone) Allows interaction with nodes on the backbone or in other subnets running different operations http://tools.ietf.org/html/draft-thubert-6lowpan-backbone-router © 2013-2014 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 42
  • © 2013-2014 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 43
  • Connected Route to subnet © 2013-2014 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 44
  • Default Route In RIB © 2013-2014 Cisco and/or its affiliates. All rights reserved. Gateway to the outside participates to some IGP with external network and attracts all extra-subnet traffic via protocols over the backbone Cisco Confidential 45
  • Directly upon NS(ARO) or indirectly upon DAR message, the backbone router performs DAD on behalf of the wireless device. NS DAD (ARO) DAD NS (ARO) NS (ARO) © 2013-2014 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 46
  • The BR maintains a route to the WSN node for the DAO Lifetime over instance VRF. VFR may be mapped onto a VLAN on the backbone. Optional NA(O) NA (ARO) DAC © 2013-2014 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 47
  • The BR maintains a route to the WSN node for the DAO Lifetime over instance VRF. VFR may be mapped onto a VLAN on the backbone. Optional NA(O) RPL DAO Host Route © 2013-2014 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 48
  • DAD option has: Unique ID TID (SeqNum) Defend with NA if: Different OUID Newer TID NS DAD (ARO) NA (ARO) NS (ARO) © 2013-2014 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 49
  • DAD option has: Unique ID TID (SeqNum) Defend with NA if: Different OUID Newer TID Optional NA(ARO) NA (ARO) with older TID (loses) RPL DAO Host Route © 2013-2014 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 50
  • NA ARO option has: Unique ID TID (SeqNum) NS lookup NA (ARO) Packet © 2013-2014 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 51
  • Resolution (2) NS lookup Mixed mode ND BBR proxying over the backbone NA (ARO) Packet © 2013-2014 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 52
  • • Used to resolve conflicts • Need In ND: TID to detect movement ->eARO • Need In RPL: Object Unique ID if we use RPL for DAD 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Length = 2 | Status | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Reserved |T| TID | Registration Lifetime | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | + OUID ( EUI-64 or equivalent ) + | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ © 2013-2014 Cisco and/or its affiliates. All rights reserved. Figure 2: EARO Cisco Confidential 53
  • 6TiSCH at a glance Deterministic IPv6 over IEEE802.15.4e TimeSlotted Channel Hopping (6TiSCH) The Working Group will focus on enabling IPv6 over the TSCH mode of the IEEE802.15.4e standard. The scope of the WG includes one or more LLNs, each one connected to a backbone through one or more LLN Border Routers (LBRs). Active drafts http://tools.ietf.org/html/draft-ietf-6tisch-terminology http://tools.ietf.org/html/draft-ietf-6tisch-tsch http://tools.ietf.org/html/draft-ietf-6tisch-architecture http://tools.ietf.org/html/draft-ietf-6tisch-minimal http://tools.ietf.org/html/draft-wang-6tisch-6top http://tools.ietf.org/html/draft-ohba-6tisch-security http://tools.ietf.org/html/draft-sudhaakar-6tisch-coap © 2013-2014 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 54
  • Routing IP in LLNs BRKEWN-3012 © 2010 Cisco and/or its affiliates. All rights reserved. Unclassified 55
  • • Hidden terminal • Interference domains grows faster that range • Density => low power => multihop => routing © 2013-2014 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 56
  • Aka stateful vs. On-demand routing Note: on-demand breaks control vs. Data plane separation © 2013-2014 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 57
  • • Aka SPF vs. Bellman-Ford • LS requires full state and convergence • LS can be very quiet on stable topologies • DV hides topolical complexities and changes © 2013-2014 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 58
  • 0 Optimized Routing Approach (ORA) spans advertisements for any change Routing overhead can be reduced if stretch is allowed: Least Overhead Routing Approach (LORA) For instance Fisheye and zone routing provide a precise routing when closeby and sense of direction when afar © 2013-2014 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 59
  • A Directed Acyclic Graph (DAG) is formed by a collection of vertices (nodes) and edges (links). 0 1 Clusterhead 2 1 1 2 Each edge connecting one node to another (directed) in such a way that it is not possible to start at Node X and follow a directed path that cycles back to Node X (acyclic). 0 2 3 2 3 2 3 2 4 3 3 A Destination Oriented DAG (DODAG) is a DAG that comprises a single root node. Here a DAG that is partitioned in 2 DODAG 3 4 3 5 5 6 44 5 4 © 2013-2014 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 60
  • 0 • In Green: A‟s subDAG. 1 1 • Impacted if A‟s connectivity is broken • Domain for routing recovery (or reverse subDAG) Potential SPAN on B‟s DAO Thus potential return paths Fanout must be controlled to limit intermediate states 1 2 0 2 3 A 2 3 2 3 • In Red: B‟s fanout DAG • • • • Clusterhead 2 2 4 3 3 3 4 3 5 5 6 44 5 4 B © 2013-2014 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 61
  • Routing over radios 63
  • No preexisting physical topology Can be computed by a mesh under protocol, but… Else Routing must infer its topology Movement natural and unescapable Yet difficult to predict or detect © 2013-2014 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 64
  • Potentially Large Peer Set Highly Variable Capabilities Metrics (e.g. RSSI, ETX…) L3 Reachability (::/0, …) Constraints (Power …) Selection Per Objective © 2013-2014 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 65
  • • Smart object are usually • Small & Numerous • « sensor Dust » • Battery is critical • Deep Sleep • Limited memory • Small CPU • Savings are REQUIRED Control plane Data plane (Compression) © 2013-2014 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 66
  • Neither transit nor P2P More like a changing NBMA • a new paradigm for routing Changing metrics • (tons of them!) • (but no classical cost!) Inefficient flooding • Self interfering QoS and CAC © 2013-2014 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 67
  • Stretch vs. Control Optimize table sizes and updates Optimized Routing Approach (ORA) vs Least Overhead Routing Approach (LORA) Non Equal Cost multipath Directed Acyclic Graphs (DAG) a MUST Maybe also, Sibling routing on-demand routes (reactive) Forwarding and retries Same vs. Different next hop Validation of the Routing plane © 2013-2014 Cisco and/or its affiliates. All rights reserved. Objective Routing Weighted Hop Count the wrong metric Instances per constraints and metrics Cisco Confidential 68
  • Pervasive Access • Satellite • 3/4G coverage • 802.11, 802.15.4 Always Reachable • at a same identifier • Preserving connections • Or not ? (CORE*, DTN**) Fast roaming • Within technology (L2) • Between Technologies (L3) * Constrained RESTful Environments ** Delay-Tolerant Networking © 2013-2014 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 69
  • RPL Concepts 70
  • RPL is an extensible proactive IPv6 DV protocol Supports MP2P, P2MP and P2P P2P reactive extension RPL specifically designed for LLNs Agnostic to underlying link layer technologies (802.15.4, PLC, Low Power WiFi) Minimum topological awareness Data Path validation Non-Equal Cost Multipath Fwd Instantiation per constraints/metrics Autonomic Subnet G/W Protocol Optimized Diffusion over NBMA © 2013-2014 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 71
  • Controlling the control … by design Distance Vector as opposed to Link State • Knowledge of SubDAG addresses and children links • Lesser topology awareness => lesser sensitivity to change • No database Synchronization => Adapted to movement Optimized for Edge operation • Optimized for P2MP / MP2P, stretch for arbitrary P2P • Least Overhead Routing Approach via common ancestor Proactive as opposed to Reactive • Actually both with so-called P2P experimental specification Datapath validation © 2013-2014 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 72
  • Control Information in Data Packets: • • • Instance ID Hop-By-Hop Header Sender Rank Direction (UP/Down) Errors detected if: No route further down for packet going down No route for packet going down Rank and direction do not match © 2013-2014 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 73
  • In the context of routing, a DAG is formed by a collection of vertices (nodes) and edges (links), each edge connecting one node to another (directed) in such a way that it is not possible to start at Node X and follow a directed path that cycles back to Node X (acyclic). © 2013-2014 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 74
  • 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | RPLInstanceID |Version Number | Rank | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |G|0| MOP | Prf | DTSN | Flags | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | + + | | + DODAGID + | | + + | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Option(s)... +-+-+-+-+-+-+-+-+ © 2013-2014 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 76
  • • : : A new DODAG iteration • Rebuild the DAG … Then repaint the prefixes upon changes • A new Sequence number generated by the root • A router forwards to a parent or as a host over next iteration • • • • • : find a “quick” local repair path Only requiring local changes ! May not be optimal according to the OF Moving UP and Jumping are cool. Moving Down is risky: Count to Infinity Control © 2013-2014 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 77
  • Extend the generic behavior • For a specific need / use case Used in parent selection • Contraints • Policies • Metrics Position in the DAG Computes the Rank increment • Based on hop metrics • Do NOT use OF0 for adhoc radios! • (OF 0 uses traditional weighted hop count) © 2013-2014 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 78
  • 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | RPLInstanceID |Version Number | Rank | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |G|0| MOP | Prf | DTSN | Flags | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | + + | | + DODAGID + | | + + | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Option(s)... +-+-+-+-+-+-+-+-+ © 2013-2014 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 79
  • +-----+-----------------------------------------------------+ | MOP | Description | +-----+-----------------------------------------------------+ | 0 | No Downward routes maintained by RPL | | 1 | Non-Storing Mode of Operation | | 2 | Storing Mode of Operation with no multicast support | | 3 | Storing Mode of Operation with multicast support | | | | | | All other values are unassigned | +-----+-----------------------------------------------------+ © 2013-2014 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 80
  • 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | RPLInstanceID |K|D| Flags | Reserved | DAOSequence | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | + + | | + DODAGID* + | | + + | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Option(s)... +-+-+-+-+-+-+-+-+ © 2013-2014 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 81
  • Parent is default GW, advertizes owned PIO (L bit on) RPL Router autoconfigures Addr from parent PIO RPL Router advertises Prefix via self to parent RPL Router also advertises children Prefix A::A A C: A::B ::/0 via B::B ::/0 via A::A C:: connected B B: B:: connected B::B A:: B::D B::C B:: connected D: C D connected ::/0 via B::B C:: via B::C D:: via B::D A: A:: connected B:: via A::B C:: via A::B D:: via A::B B:: connected D:: connected © 2013-2014 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 82
  • For Your Reference Parent is default GW, propagates root PIO (L-bit off) Parent Address in the PIO (with R bit) RPL Router autoconfigures Address from parent PIO RPL Router advertises Address via self to parent RPL Router also advertises children Addresses A::A A C: ::/0 via A::B A::B A::B A::C B A:: A::D A::C C D connected self ~onlink ::/0 via A::A A::A connected A::B ::/0 via A::B connected A::D connected A::D connected A:: ~onlink A: A::A self A::B connected A::C via A::B A::D via A::B A:: ~onlink self A:: self A::C D: A::B © 2013-2014 Cisco and/or its affiliates. All rights reserved. B: ~onlink Cisco Confidential 83
  • Parent is default GW, propagates root PIO (L-bit off) Parent Address in the PIO (with R bit) RPL Router autoconfigures Address from parent PIO RPL Router advertises Address via Parent to Root Root recursively builds a Routing Header back A::A A C: ::/0 via A::B A::B Target A::C via Transit A::B A::B A::C A::D A::C self ~onlink ::/0 via A::A A::A self A::B A::D via A::B ~onlink A::B connected self ~onlink via ~onlink A:: © 2013-2014 Cisco and/or its affiliates. All rights reserved. A:: A::C self connected connected A:: ::/0 via A::B A::B A::B A::A connected A::D D D: A::B C A: (root) B: A:: B connected A::D via Cisco Confidential 84
  • For Your Reference Parent is default GW, advertizes owned PIO (L bit on) RPL Router autoconfigures Address from parent PIO RPL Router advertises Prefix via Address to Root Root recursively builds a Routing Header back A::A A C: A::B B:: connected B::B C:: connected B A:: D: C D A: (root) B: A:: ::/0 via A::A B::D B::C Target C::/ via Transit B::C ::/0 via B::B connected B:: via A::B C:: via B::C D:: via B::D connected B:: connected ::/0 via B::B B:: connected D:: connected © 2013-2014 Cisco and/or its affiliates. All rights reserved. D::3 via B::D via A::B connected Cisco Confidential 85
  • Hidden node/terminal/station A B C D © 2013-2014 Cisco and/or its affiliates. All rights reserved. Flooding interferes with itself Cisco Confidential 86
  • Suppression of redundant copies Do not send copy if K copies received Jitter for Collision Avoidance First half is mute, second half is jittered Exponential backoff Double I after period I, Reset I on inconsistency © 2013-2014 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 87
  • For Your Reference Node Metrics Link Metrics Node State and Attributes Object Purpose is to reflects node workload (CPU, Memory…) “O” flag signals overload of resource “A” flag signal node can act as traffic aggregator Throughput Object Currently available throughput (Bytes per second) Throughput range supported Node Energy Object “T” flag: Node type: 0 = Mains, 1 = Battery, 2 = Scavenger “I” bit: Use node type as a constraint (include/exclude) “E” flag: Estimated energy remaining Latency Can be used as a metric or constraint Constraint - max latency allowable on path Metric - additive metric updated along path Hop Count Object Can be used as a metric or constraint Constraint - max number of hops that can be traversed Metric - total number of hops traversed Link Reliability Link Quality Level Reliability (LQL) 0=Unknown, 1=High, 2=Medium, 3=Low Expected Transmission Count (ETX) (Average number of TX to deliver a packet) Link Colour Metric or constraint, arbitrary admin value © 2013-2014 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 88
  • Applying RPL 89
  • At a given point of time connectivity is (fuzzy) Radio link © 2013-2014 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 91
  • 1st • • • • pass (DIO) Establishes a logical DAG topology Trickle Subnet/config Info Sets default route Self forming / self healing 0 1 Clusterhead 2 1 1 2 2 3 2 3 2 3 4 2 2nd pass (DAO) • • • • • paints with addresses and prefixes Any to any reachability But forwarding over DAG only saturates upper links of the DAG And does not use the full mesh properly 4 4 3 5 6 3 4 5 5 Potential link Link selected as parent link © 2013-2014 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 92
  • 0 1 Clusterhead 2 A‟s link to root fails 1 1 2 A loses connectivity Either poisons or detaches a subdag A 2 3 2 3 2 3 4 In black: 2 4 4 the potentially impacted zone That is A‟s subDAG 3 5 6 3 4 5 5 Potential link Link selected as parent link © 2013-2014 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 93
  • 0 1 Clusterhead 2 1 B can reparent a same Rank so B‟s subDAG is safe 0 2 A 2 3 2 B 3 1 The rest of A‟s subDAG is isolated 3 1 4 4 4 Either poison ar build a floating DAG as illustrated In the floating DAG A is root The structure is preserved 2 5 6 2 4 5 5 Potential link Link selected as parent link © 2013-2014 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 94
  • 0 1 Clusterhead 2 1 Once poisined nodes are identified 2 2 It is possible for A to reparent safely A 2 3 2 3 A‟s descendants inherit from Rank shift 3 3 4 3 4 Note: a depth dependent timer can help order things 4 4 5 6 4 4 5 5 Potential link Link selected as parent link © 2013-2014 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 95
  • 0 1 Clusterhead 3 1 A new DAG iteration • In Grey, the new DAG progressing 2 3 2 3 Metrics have changed, the DAG may be different Forwarding upwards traffic from old to new iteration is allowed but not the other way around 1 2 2 3 4 2 4 4 3 5 6 3 4 5 5 Potential link Link selected as parent link © 2013-2014 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 96
  • 0 A second root is available 1 • (within the same instance) 1 0 2 3 2 1 root = 1 DODAG 3 2 3 1 Node belongs to 1 DODAG 2 4 • (at most, per instance) 3 3 Nodes may JUMP 3 4 • from one DODAG to the next • up the DODAG 1 2 The DAG is partitioned Nodes may MOVE Clusterhead 2 3 5 5 6 44 5 4 Going Down MAY cause loops • May be done under CTI control Potential link Link selected and oriented by DIO © 2013-2014 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 97
  • 0 Running as Ships-in-the-night 1 Clusterhead 2 1 1 instance = 1 DAG 1 2 A DAG implements constraints 2 3 2 3 Serving different Objective Functions 2 3 4 2 3 For different optimizations Forwarding along a DODAG (like A a vlan) 3 3 4 5 4 3 4 Potential link Constrained instance Default instance © 2013-2014 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 98
  • New Radios issues: Addressed in RPL by: Dynamic Topologies DV, ORA P2MP/MP2P, LORA P2P Peer selection Objective Functions, Metrics Constrained Objects Controlling the control Fuzzy Links NECM Directed Acyclic Graphs Trickle and Datapath validation Routing, local Mobility Local and Global Recovery Global Mobility N/A © 2013-2014 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 99
  • RFC 6206: The Trickle Algorithm RFC 6550: RPL: IPv6 Routing Protocol for LLNs RFC 6551: Routing Metrics Used for Path Calculation in LLNs RFC 6552: Objective Function Zero for the Routing Protocol for LLNs RFC 6553: RPL Option for Carrying RPL Information in Data-Plane Datagrams RFC 6554: An IPv6 Routing Header for Source Routes with RPL RFC 6719: MRHOF Objective Function with hysteresis draft-ietf-roll-trickle-mcast: Multicast Protocol for LLNs draft-vilajosana-6tisch-minimal: Minimal 6TiSCH Configuration © 2013-2014 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 100
  • The Internet is going through its most considerable change since the first days, adding a nervous system to the bug brain. Potential is immense and unpredictable. Made possible by IPv6 But not at the core and unbeknownst to the core Stimulated by radio access Enabling new devices and usages The change happens in the Fringe, which is in fact a collection of virtualized fringes. The polymorphic Internet is already there. © 2013-2014 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 101
  • “We might be at the eve of pervasive networking, a vision for the Internet where every person and every device is connected to the network in the ultimate realization of Metcalf's Law.” © 2013-2014 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 102