Weitere ähnliche Inhalte Ähnlich wie Rpl telecom bretagne (20) Rpl telecom bretagne2. 1000*scale => No leak in the Internet
=> Opaque Fringe operations
Reachability => Radio
Addressing => IPv6
Density => spatial
reuse
=> Routing
Telecom Bretagne © 2012 Cisco and/or its affiliates. All rights reserved. Unclassified 2
3. Agenda (part 1)
The Fringe of the Internet
Radios and LLNs
IEEE 802.15.4
Mesh-Under Fringe
Route-Over Fringe
Overlay Fringe
Telecom Bretagne © 2012 Cisco and/or its affiliates. All rights reserved. Unclassified 3
4. Agenda (Part 2)
The RPL Fringe protocol
Going IP
Routing IP
Routing over Radio
RPL concepts
Applying RPL
Telecom Bretagne © 2012 Cisco and/or its affiliates. All rights reserved. Unclassified 4
6. The routing Infrastructure today
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
Telecom Bretagne © 2012 Cisco and/or its affiliates. All rights reserved. Unclassified 6
7. The emerging Fringe of the Internet
L2 mesh Under
A Multi-hop Public Access Points,
4 Proprietary mission specific products
3 Address the scale issue at L2/ND
2 Edge
1 L3 Route Over
Migration to IETF Protocols (RPL)
NEMO Internet of Things (IOT, M2M)
B’s Different IPv6 (6LoWPAN, SDN)
A’s
Home Home
Mobile Overlays
Fixed wired Global reachability
Infrastructure Route Projection
Network virtualization
5 MANET
Mesh 6 The Fringe DOES NOT LEAK
7
8 into the
B C Routing Infrastructure
Telecom Bretagne © 2012 Cisco and/or its affiliates. All rights reserved. Unclassified 7
9. Wireless: the evolution trait
Cheap multipoint access
New types of devices (Internet Of Things)
New usages (X-automation, Mobile Internet)
Cheap Install
Deploying wire is slow and costly
Global Coverage
From Near Field to Satellite via 3/4G
Everywhere copper/fiber cannot reach
Telecom Bretagne © 2012 Cisco and/or its affiliates. All rights reserved. Unclassified 9
10. Low Power Lossy Network (LLN)
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
Telecom Bretagne © 2012 Cisco and/or its affiliates. All rights reserved. Unclassified 10
11. Characteristics of LLNs
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
Many LLN nodes do not have resources to waste
Telecom Bretagne © 2012 Cisco and/or its affiliates. All rights reserved. Unclassified 11
12. IETF LLN Related Workgroups
Constrained Restful
Application Core Environments
Charter to provide a framework for resource-
oriented applications intended to run on
constrained IP networks.
General 6TSCH
IPv6 over Low power WPAN
Charter is to develop protocols to support IPv6
Internet 6LowPAN running over IEEE 802.15.4 low-power radio
networks.
Lightweight Implementation Guidance
IETF Ops and Mgmt Charter is to provide guidance in building
LWIG
minimal yet interoperable IP-capable devices for
the most constrained environments. .
Routing over Low Power Lossy
Routing ROLL Networks
Charter focusses on routing issues for low power
lossy networks.
Security
Reuse work done here where possible
Transport
Telecom Bretagne © 2012 Cisco and/or its affiliates. All rights reserved. Unclassified 12
14. 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 is likely to be 802.15 (PAN)
http://www.ieee802.org/15/pub/TG4.html
The only IEEE 802 Working Group with IEEE 802.15 WPAN™ Task Group 4
multiple MACs (TG4) Charter
© 2012 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 14
15. IEEE Wireless Standards
802.15.4
Amendments
802.11 Wireless WiFi
LAN 802.11a/b/g/n/ah
802.15 Personal 802.15.1 802.15.4c
Area Network Bluetooth PHY for China
IEEE 802 TSCH
LAN/MAN
802.15.2 802.15.4d
802.16 Wireless Co-existence PHY for Japan
Broadband Access
• Industrial strength
802.15.4e • Minimised listening costs
802.15.3
MAC • Improved security
High Rate WPAN
802.22 Wireless Enhancements • Improved link reliability
Regional Area Network
802.15.4 802.15.4f
Low Rate WPAN PHY for RFID • Support smart-grid networks
• Up to 1 Km transmission
• >100Kbps
802.15.5 802.15.4g • Millions of fixed endpoints
Mesh Networking Smart Utility Networks • Outdoor use
• Larger frame size
• PHY Amendment
802.15.6 Body Area TV White Space PHY • Neighborhood Area Networks
Networking 15.4 Study Group
802.15.7 Visible
Light
Communications
Telecom Bretagne © 2012 Cisco and/or its affiliates. All rights reserved. Unclassified 15
16. IEEE 802.15.4 Features
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)
Telecom Bretagne © 2012 Cisco and/or its affiliates. All rights reserved. Unclassified 16
17. 802.15.4 Protocol Stack
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 Upper
Layers
Channel access management
(Network &
Device association/disassociation App)
Sending ACK frames
Physical Layer (PHY) MAC Layer
Provides bit stream air transmission (MAC)
Activation/Deactivation of radio transceiver
Frequency channel tuning
Carrier sensing Physical
Received signal strength indication (RSSI) Layer
Link Quality Indicator (LQI) (PHY)
Data coding and modulation, Error correction
Telecom Bretagne © 2012 Cisco and/or its affiliates. All rights reserved. Unclassified 17
18. 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
Coordinated Sampled Listening (CSL)
Channel Hopping
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)
Telecom Bretagne © 2012 Cisco and/or its affiliates. All rights reserved. Unclassified 18
19. R
F R
IEEE 802.15.4 Node Types P
R F
Full Function Device (FFD)
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
Telecom Bretagne © 2012 Cisco and/or its affiliates. All rights reserved. Unclassified 19
20. IEEE 802.15.4 Topologies
Operates at Layer 2
• Star Topology • Mesh Topology • Cluster Tree
R F R R R
F R F P R F F
P F R P
R F F F F F
• All devices R R R R
communicate to PAN
• Devices can • Higher layer protocols
co-ordinator which
communicate directly like RPL may create
uses mains power
if within range their own topology
• Other devices can be that do not follow
battery/scavenger 802.15.4 topologies
Single PAN co-ordinator exists for all topologies
Telecom Bretagne © 2012 Cisco and/or its affiliates. All rights reserved. Unclassified 20
22. Wireless Industrial
• 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
Telecom Bretagne © 2012 Cisco and/or its affiliates. All rights reserved. Unclassified 22
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
Telecom Bretagne © 2012 Cisco and/or its affiliates. All rights reserved. Unclassified 23
25. Swarming
! IPv6
IPv6
Mobile Router
SOS
Emergency
HotSpot IPv6
(roadside)
Mobile Router
Telecom Bretagne © 2012 Cisco and/or its affiliates. All rights reserved. Unclassified 25
26. Sensor Dust
“Sensor dust” spread over a territory
Sensors assume a fixed arbitrary
geographical distribution
Numerous sensors with limited
capabilities (battery …)
A limited number of relays (MR)
MRs run an SGP (RPL)
2 to 3 uplinks (MR with backhaul
capability)
Telecom Bretagne © 2012 Cisco and/or its affiliates. All rights reserved. Unclassified 26
27. Fleet
Global motion plus relative
mobility TLMR
Managed hierarchy over
dynamic topology
Secured uplink to base
Dark Zone coverage and
range extension (nesting)
Telecom Bretagne © 2012 Cisco and/or its affiliates. All rights reserved. Unclassified 27
28. Nested NEMO Route optimization
HA1 CN1
CN2
HA2
CN
Internet
MR1
HA
HA1: HA of MR1 VMN
HA2: HA of MR2
HA-VMN: HA of VMN
CR: Correspondent Router MR2
Telecom Bretagne © 2012 Cisco and/or its affiliates. All rights reserved. Unclassified 28
29. Couple LISP/MIP/NEMO LISP /
with global mobility with MIP /
NEMO
local meshing/routing 1
0
Clusterhead
(typically RPL) 2
1
1
2
Locator is root, routing 3
2
between device 3
2
2
identifiers 3
4 2
e.g. Home Network 3
3
Potential link 3
4
Default routing 3
5 4
Constrained routing 4
Telecom Bretagne © 2012 Cisco and/or its affiliates. All rights reserved. Unclassified 29
31. Why IPv6 ?
Going IP
BRKEWN-3012 © 2010 Cisco and/or its affiliates. All rights reserved. Unclassified 31
32. 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
Telecom Bretagne © 2012 Cisco and/or its affiliates. All rights reserved. Unclassified 32
33. 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 !
APNIC: May 2011; RIPE NCC: Sept 2012 (last /8)
Tens of
Things Billions
Smart Objects
Mobile 2~4 Billions
Phones & cars
Fixed 1~2 Billions
PCs & servers
Telecom Bretagne © 2012 Cisco and/or its affiliates. All rights reserved. Unclassified 33
34. Protocol Evolution
Little work on adapting IPv4 to radios
Rather adapt radios to IPv4 e.g. WIFI
infrastructure mode
« Classical » IPv6
Large, Scoped and Stateful addresses
Neighbor Discovery, RAs (L3 beacons)
SLAAC (quick and scalable)
Anycast Addresses
IPv6 evolution meets Wireless:
Mobile Routers (LISP, NEMO) (Proxy) MIPv6
6LoWPAN 6TSCH ROLL/RPL CoAP
ISA100.11a ZigBee/IP
Telecom Bretagne © 2012 Cisco and/or its affiliates. All rights reserved. Unclassified 34
35. IPv6 still lacks
NBMA / ML subnet
IPv6 only supports P2P and transit (ethernet)
By nature, a radio network is NBMA
L3 « VLAN »
So far only available with MPLS
Early attempts (MTR, RPL instances)
L4/5 hints
Flow Label given away to fwd plane
Microflows / compound flows
In WSN, a flow has multiple sources
Local and Global IP Mobility Unification
(eg MANEMO, LISP+RPL)
Telecom Bretagne © 2012 Cisco and/or its affiliates. All rights reserved. Unclassified 35
37. Routing for Spatial Reuse
Hidden terminal
Interference domains grows faster that range
Density => low power => multihop => routing
Telecom Bretagne © 2012 Cisco and/or its affiliates. All rights reserved. Unclassified 37
39. Link State vs. Distance Vector
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
Telecom Bretagne © 2012 Cisco and/or its affiliates. All rights reserved. Unclassified 39
40. Route stretch and fisheye
Optimized Routing Approach
0 (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
Telecom Bretagne © 2012 Cisco and/or its affiliates. All rights reserved. Unclassified 40
41. DAG, DODAG
In the context of routing, a 1
0
Clusterhead
Directed Acyclic Graph (DAG) is 2
formed by a collection 2
1 1
0
of vertices (nodes) and edges 3
2
(links). 3
2
2
Each edge connecting one node 3
4 2
to another (directed) in such a 3
way that it is not possible to start 3
at Node X and follow a directed 4
3
path that cycles back to Node X 5
3
(acyclic). 5
6
44 5
A Destination Oriented DAG 4
(DODAG) is a DAG that
comprises a single root node.
Here a DAG that is partitioned in
2 DODAG
Telecom Bretagne © 2012 Cisco and/or its affiliates. All rights reserved. Unclassified 41
42. SubDAG, and Fanout DAG
0
1 Clusterhead
In Green: A’s subDAG. 2
1 1
Impacted if A’s connectivity is
2 0
2
broken 3 A
2
3 2
Domain for routing recovery 3
4 2
In Red: B’s fanout DAG 3
3
(or reverse subDAG) 4
3
Potential SPAN on B’s DAO 5
3
5
Thus potential return paths 6
44 5
Fanout must be controlled to 4
limit intermediate states B
Telecom Bretagne © 2012 Cisco and/or its affiliates. All rights reserved. Unclassified 42
44. Dynamic topologies
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
Telecom Bretagne © 2012 Cisco and/or its affiliates. All rights reserved. Unclassified 45
45. Peer selection
Potentially Large Peer Set
Metrics (e.g. RSSI, ETX…)
Highly Variable Capabilities L3 Reachability (::/0, …)
Constraints (Power …)
Selection Per Objective
Telecom Bretagne © 2012 Cisco and/or its affiliates. All rights reserved. Unclassified 46
46. Constrained Objects
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)
Telecom Bretagne © 2012 Cisco and/or its affiliates. All rights reserved. Unclassified 47
47. Fuzzy links
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
Telecom Bretagne © 2012 Cisco and/or its affiliates. All rights reserved. Unclassified 48
48. Local Routing & Mobility
Stretch vs. Control
Non Equal Cost multipath
Optimize table sizes and updates
Directed Acyclic Graphs (DAG) a MUST
Optimized Routing Approach (ORA) vs
Maybe also, Sibling routing
Least Overhead Routing Approach (LORA)
on-demand routes (reactive)
Objective Routing
Forwarding and retries
Weighted Hop Count the wrong metric
Same vs. Different next hop
Instances per constraints and metrics
Validation of the Routing plane
Telecom Bretagne © 2012 Cisco and/or its affiliates. All rights reserved. Unclassified 49
49. Global Mobility
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
Telecom Bretagne © 2012 Cisco and/or its affiliates. All rights reserved. Unclassified 50
50. What’s missing
A radio abstraction
802.21, L2 triggers, OmniRAN
Roaming within and between technologies
TSCH model
A subnet model
NBMA, interference awareness
Federation via backbone / backhaul
Broadcast and look up optimization
Large scale
non-aggregatable
numbering and naming schemes
Telecom Bretagne © 2012 Cisco and/or its affiliates. All rights reserved. Unclassified 51
52. Routing With RPL
Low Power Lossy Nets Addressed in RPL ?
Dynamic Topologies
Peer selection
Constrained Objects
Fuzzy Links
Routing, local Mobility
Global Mobility
Telecom Bretagne © 2012 Cisco and/or its affiliates. All rights reserved. Unclassified 53
53. RPL key concepts
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
Telecom Bretagne © 2012 Cisco and/or its affiliates. All rights reserved. Unclassified 54
54. 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 draft
Datapath validation
Telecom Bretagne © 2012 Cisco and/or its affiliates. All rights reserved. Unclassified 55
55. Datapath Validation
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
Telecom Bretagne © 2012 Cisco and/or its affiliates. All rights reserved. Unclassified 56
56. Directed Acyclic Graph for NECM
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).
Telecom Bretagne © 2012 Cisco and/or its affiliates. All rights reserved. Unclassified 57
57. Generic Rank-based Loop Avoidance
1) A root has a Rank of 1. A
router has a Rank that is higher
than that of its DAG parents. 4) But the Router MUST NOT move
down its DAG
2) A Router that is no more – but under controlled limits
attached to a DAG MUST poison whereby the router is allowed a
its routes, either by advertising limited excursion down
an INFINITE_RANK or by
forming a floating DAG. 5) A Router MAY jump from its
current DAG into any different
3) A Router that is already part DAG at any time and whatever
of a DAG MAY move at the Rank it reaches there,
any time in order to get closer unless it has been a member of
to the root of its current DAG the new DAG in which case rule
in order to reduce its own Rank 4) applies
Telecom Bretagne © 2012 Cisco and/or its affiliates. All rights reserved. Unclassified 58
58. DIO Base Object: forming the DODAG
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)...
+-+-+-+-+-+-+-+-+
Telecom Bretagne © 2012 Cisco and/or its affiliates. All rights reserved. Unclassified 59
59. Global versus Local Repair
: : 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
Telecom Bretagne © 2012 Cisco and/or its affiliates. All rights reserved. Unclassified 60
60. Objective Function
Extend the generic behavior
For a specific need / use case
Used in parent selection
Contraints
Policies Position in the DAG
Metrics
Computes the Rank increment
Based on hop metrics
Do NOT use OF0 for adhoc radios!
(OF 0 uses traditional weighted hop count)
Telecom Bretagne © 2012 Cisco and/or its affiliates. All rights reserved. Unclassified 61
61. DIO Base Object: route construction rules
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)...
+-+-+-+-+-+-+-+-+
Telecom Bretagne © 2012 Cisco and/or its affiliates. All rights reserved. Unclassified 62
62. Mode of Operation
+-----+-----------------------------------------------------+
| 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 |
+-----+-----------------------------------------------------+
Telecom Bretagne © 2012 Cisco and/or its affiliates. All rights reserved. Unclassified 63
63. DAO Base Object : route construction
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)...
+-+-+-+-+-+-+-+-+
Telecom Bretagne © 2012 Cisco and/or its affiliates. All rights reserved. Unclassified 64
64. Owned prefix routing (storing mode)
Parent is default GW, advertizes owned PIO (L bit on)
A::A RPL Router autoconfigures Addr from parent PIO
RPL Router advertises Prefix via self to parent
RPL Router also advertises children Prefix
A
C:
A::B
B::B ::/0 via B::B B:
A:
B:: connected ::/0 via A::A
B A:: connected
C:: connected A:: connected
B::D B:: via A::B
B::C B:: connected
D: C:: via A::B
C:: via B::C
C D ::/0 via B::B D:: via A::B
D:: via B::D
B:: connected
D:: connected
Telecom Bretagne © 2012 Cisco and/or its affiliates. All rights reserved. Unclassified 65
65. For Your
Subnet Routing (storing mode) Reference
Parent is default GW, propagates root PIO (L-bit off)
Parent Address in the PIO (with R bit)
A::A RPL Router autoconfigures Address from parent PIO
RPL Router advertises Address via self to parent
RPL Router also advertises children Addresses
A
C:
::/0 via A::B
A::B B:
A::B connected
A:
::/0 via A::A
A::C self
B A::A self
A::A connected
A:: ~onlink
A::B connected
A::D A::B self
A::C D: A::C via A::B
A::C connected
::/0 via A::B A::D via A::B
C D A::D connected
A::B connected A:: ~onlink
A:: ~onlink
A::D self
A:: ~onlink
Telecom Bretagne © 2012 Cisco and/or its affiliates. All rights reserved. Unclassified 66
66. Subnet Routing (non-storing mode)
Parent is default GW, propagates root PIO (L-bit off)
Parent Address in the PIO (with R bit)
A::A RPL Router autoconfigures Address from parent PIO
RPL Router advertises Address via Parent to Root
Root recursively builds a Routing Header back
A
C:
::/0 via A::B Target A::C via
A::B Transit A::B A: (root)
A::B connected
A::C self A::A self
B B:
A:: ~onlink A::B connected
::/0 via A::A
A::C A::D A::C via A::B
D: A::A connected
A::D via A::B
::/0 via A::B A::B self
C D A:: ~onlink
A::B connected A:: ~onlink
A::D self
A:: ~onlink A::D via A::B connected
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67. For Your
Owned prefix routing (non-storing mode) Reference
Parent is default GW, advertizes owned PIO (L bit on)
RPL Router autoconfigures Address from parent PIO
A::A
RPL Router advertises Prefix via Address to Root
Root recursively builds a Routing Header back
A
C:
Target C::/ via
::/0 via B::B Transit B::C
A::B
B::B B:: connected
C:: connected A: (root)
B B:
A:: connected
::/0 via A::A
B::C B::D B:: via A::B
A:: connected
D: C:: via B::C
B:: connected
C D ::/0 via B::B D:: via B::D
B:: connected
D:: connected D::3 via B::D via A::B connected
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68. Multicast over radio NBMA
Hidden node/terminal/station
A
B
C
D Flooding interferes with itself
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69. Trickle:
An Optimized Diffusion
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
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70. For Your
Routing Metrics in LLNs Reference
Node Metrics Link Metrics
Node State and Attributes Object Throughput Object
Purpose is to reflects node workload (CPU, Currently available throughput (Bytes per
Memory…) second)
“O” flag signals overload of resource Throughput range supported
“A” flag signal node can act as traffic
aggregator
Node Energy Object Latency
“T” flag: Node type: 0 = Mains, 1 = Battery, 2 = Can be used as a metric or constraint
Scavenger Constraint - max latency allowable on path
“I” bit: Use node type as a constraint Metric - additive metric updated along path
(include/exclude)
“E” flag: Estimated energy remaining
Hop Count Object Link Reliability
Can be used as a metric or constraint Link Quality Level Reliability (LQL)
Constraint - max number of hops that can be 0=Unknown, 1=High, 2=Medium, 3=Low
traversed Expected Transmission Count (ETX)
Metric - total number of hops traversed (Average number of TX to deliver a
packet)
Link Colour
Metric or constraint, arbitrary admin value
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72. RPL Instance
RPL Terminology Consists of one or more DODAGs sharing SAME service type
(Objective Function)
Identified by RPL INSTANCE ID
Direction Oriented DAG (DODAG)
Comprises DAG with a single root
Node DODAG
Rank = n (OF Rank > n
DODAG
configured)
Siblings
DOWN (DIO Messages)
5
UP (DAO Messages)
Rank 5
Rank decreases
Rank increases
Sub-
Towards
DODAG
4 4 5
Towards
DODAG
4 4 DODAG
Root
leafs
DODAG
parent 3
3 Sensor
3 to child
Node
“5”s 2
3 2 2
Rank < n Rank = n
1 Non-LLN 1
DODAG Root DODAG Root
Network
Identified by DODAG ID Rank is always “1”
(IPv6 Backbone)
(Node IPv6 address) (Typically an LBR - LLN
Border Router)
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73. Example radio connecticity
At a given point of
time connectivity is
(fuzzy)
Radio link
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74. Applying RPL
0
1 Clusterhead
2
1
1st pass (DIO) 2
1
Establishes a logical DAG topology 3
2
2
Trickle Subnet/config Info 3 2
Sets default route 3
4 2
Self forming / self healing 4
4
3
5
2nd pass (DAO)
3
paints with addresses and prefixes 6 4
Any to any reachability 5
5
But forwarding over DAG only
saturates upper links of the DAG
And does not use the full mesh properly Potential link
Link selected as parent link
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75. Local recovery (step 1)
0
1 Clusterhead
2
1
A’s link to root fails 2
1
A loses connectivity 3
2 A
2
Either poisons or detaches a subdag 3 2
3
4 2
In black: 4
4
the potentially impacted zone 5
3
That is A’s subDAG 6 4
3
5
5
Potential link
Link selected as parent link
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76. Local recovery (step 2)
0
1 Clusterhead
2
1
B can reparent a same Rank so 2
0
B’s subDAG is safe 2 A
3
2 B
3 1
The rest of A’s subDAG is isolated 4
3
1
4
4
2
Either poison ar build a floating 5
DAG as illustrated 2
6 4
In the floating DAG A is root
5
5
The structure is preserved
Potential link
Link selected as parent link
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77. Local recovery (step 3)
0
1 Clusterhead
2
1
Once poisined nodes are 2
2
identified 2 A
3
2
It is possible for A to reparent safely 3 3
A’s descendants inherit from Rank 3
4 3
shift 4
4
Note: a depth dependent timer can
4
help order things 5
4
6 4
5
5
Potential link
Link selected as parent link
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78. Global recovery
0
1 Clusterhead
3
1
A new DAG iteration 2
1
In Green, the new DAG progressing 3
2
2
Metrics have changed, the DAG may be 3 2
different 3
4 2
Forwarding upwards traffic from old to 4
new iteration is allowed but not the other 4
way around 5
3
3
6 4
5
5
Potential link
Link selected as parent link
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79. Multiple DODAGs within Instance
0
1 Clusterhead
A second root is available 2
1 1
(within the same instance) 2 0
2
The DAG is partitioned 3
2
3 2
1 root = 1 DODAG
3
1 Node belongs to 1 DODAG 4 2
3
(at most, per instance) 3
3
Nodes may JUMP 4
from one DODAG to the next 5
5
3
Nodes may MOVE 6
44 5
up the DODAG 4
Going Down MAY cause loops
May be done under CTI control Potential link
Link selected and oriented by DIO
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80. Multiple Instances
0
Clusterhead
Running as Ships-in-the- 2
1
1
night 2
1
2
3
1 instance = 1 DAG 2
3 2
A DAG implements 4
3
2
constraints 3
3
3
Serving different Objective 4
Functions A 5 4
3
For different optimizations 4
Forwarding along a
DODAG (like a vlan) Potential link Constrained instance
Default instance
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81. Simulation Results For Your
Reference
Traffic Control
Traffic Holes – Global Repair only
Routing Table
Sizes
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82. Summary
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
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83. Next steps…
Reactive model (in IESG review, aka P2P RPL)
PCE (ala TSMP/ISA100.11a/WiHART)
DAG limitations
Sibling routing, more resilient schemes (ARCs)
Stimulated updates (lookup)
Asymmetrical links
Multi-Topology routing and cascading
A model for 802.15.4e
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84. Conclusion
The Internet is going through its most considerable
change since the first days
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
L2 divide vs. L3 and L4
Home, IOT, cars, datacenters, industrial…
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Hinweis der Redaktion 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. 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). OmniRAN Functionality Menu• Network Discovery and Selection• Authentication & Security• Provisioning• Accounting, Charging, and Settlement• Connection Management• QoS, Admission Control and Service Flow• Power Management• Interworking and Roaming• Radio Resource Management• Operation, Administration, Maintenance and Provisioning• Lawful Interception• Location Services• Emergency Telecommunications Service• VoIP 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).