1 (6TiSCH) Applying PCE to (IPv6-based) Deterministic Networks (in IoT) Pascal Thubert Cisco Systems March 23rd, 2015 Leveraging PCE For Deterministic Networking (DetNet) https://tools.ietf.org/html/draft-finn-detnet-architectur e
Jan 12, 2016
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(6TiSCH)Applying PCE
to(IPv6-based)
Deterministic Networks(in IoT)
Pascal Thubert
Cisco SystemsMarch 23rd, 2015
Leveraging PCEFor Deterministic
Networking(DetNet)
https://tools.ietf.org/html/draft-finn-detnet-architecture
6TiSCH@IETF92
Time Sensitive NetworkingNew level of (Deterministic?) guarantees
– A differentiator for high-end forwarding engines– Sharing physical resources with classical networking– For traffic known a priori (control loops…)– Time Synchronization and global Schedule
6TiSCH@IETF92
The Train Analogy
End-to-End latency enforced by timed pause at station
Periodic trains along a same path and same schedule
Collision avoidance on the rails guaranteed by schedule
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6TiSCH@IETF92
The Bus AnalogyA bus every T. minutes, Stop A to Stop B in X. minutes
Worst end-to-end delivery time < (T + X)
Every packet in an Airbus 380 takes a bus across the fabric
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6TiSCH@IETF92
Who needs Deterministic Networking?Two classes of bleeding-edge customers, Industrial and Audio/Video.
Both have moved into the digital world, and some are using packets, but now they all realize they must move to Ethernet, and most will move to the Internet Protocols.
1.Industrial: process control, machine control, and vehicles.– On LLNs, this is a Wireless HART, ISA100.11a, WIA-PA/FA, … and 6TiSCH– On Ethernet, this is IEEE 802.1 Time-Sensitive Networking (TSN)– Data rate per stream very low, but can be large numbers of streams.– Latency critical to meeting control loop frequency requirements.
2.Audio/video: streams in live production studios.– At Layer 2, this is IEEE 802.1 Audio Video Bridging (AVB).– Not so many flows, but one flow is 3 Gb/s now, 12 Gb/s tomorrow.– Latency and jitter are important, as buffers are scarce at these speeds.
3.Vehicule, SmartGrid: streams in live production studios
Norm Finn 5
6TiSCH@IETF92
Determinism: Back to physical
It’s all about
–Real boxes and links–Real buffers and
queues–Real packets–Real Time
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It’s not about– Classical Layers– Standard bodies– QoS and stat mux
6TiSCH@IETF92
Basic Dataplane Model
• Single nailed-up path
Sender(Talker)
NIC
NIC
Flow ID
Receiver(Listener)
Per-Flow State
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6TiSCH@IETF92
Adding seamless redundancy
Replication & Elimination of individual packets
Sender(Talker)
NIC
NIC
Flow ID
Receiver(Listener)
Per-Flow State
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6TiSCH@IETF92
Network Capabilities (TEAS-like)
Control (southbound) interface
Service (northbound) interface
Topology,resources
Sender(Talker)
NIC
NIC
Receiver(Listener)
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Controller
6TiSCH@IETF92
In-band reservations (CCAMP-type)
Control (southbound) interface
User/app/
service
Per-Flow State
TSpec
User/app/
service
Controller
Service (northbound) interface
?
Reservationrequest
Sender(Talker)
NIC
NIC
Flow ID
Receiver(Listener)
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6TiSCH@IETF92
Direct Reservations from Controller
Sender(Talker)
User/app/
service
NIC
NIC
Per-Flow State
TSpec
User/app/
service
Controller
Flow ID
?
Service (northbound) interface
Receiver(Listener)
?
?
UNIinterface
Control (southbound) interface
UNIinterface 11
6TiSCH@IETF92
Expanding the Controller view
Controller
Service (northbound) interface
Control (southbound) interface
Command andConfiguration
(CLI-type operation)
Track Computation
And Maintenance
(PCE)
Measurement and Fault
Management(ops
management)
Triggerrecompute
Push update
6TiSCH@IETF92
Key take-aways on 6TiSCH• Time synchronization for network nodes and hosts to order
of (10s of) µs.• Software for resource reservation for critical data streams
(buffers and schedulers in network nodes and bandwidth on links), via configuration, management, and/or protocol action. PCE/CCAMP/TEAS connections.
• Ensure extraordinarily low packet loss ratios, order of 10–5 or better, and a guaranteed end-to-end latency for a reserved flow along track.
• Also optimized battery life by synchronizing wakeup• Convergence of critical data streams and other QoS
features, including best-effort RPL, on a single scheduled network.
Norm Finn 13
6TiSCH@IETF92 14
Thanks!