Discussion on DDS protocol binding PRO-2016-0103-Discussion_on_DDS_Protocol_Binding Discussion on DDS protocol binding Group Name: WG2&3 Joint Session Source: JunKwon Jung, KETI, jkjung@imtl.skku.ac.kr SungChan Choi, KETI, csc@keti.re.kr Meeting Date: 2016-03-17 Agenda Item: WI-00xx

Overview of Message Protocols Protocol / Traits Architecture Style Intended or Actual Deployment Relative position to other protocols Data Model / Data Representation Messaging Security CoAP Client / server model P2P RESTful IoT networks with low power constrained sensors such as smart metering Above UDP (or DTLS/ UDP) Plain text, XML, JSON, EXI, octet-stream Support for content negotiation Request / Response, Pub- Sub Largely depends on lower layers MQTT Client / Server model. Brokered style Low bandwidth, high latency networks MQTT runs above TCP (or TLS/TCP) No formal data model Publish- Subscribe Authentication: Userid / password can be passed in a packet. SSL / TLS can be used HTTP WWW Above TCP (or TLS/TCP) XML, JSON, etc. Support for Content negotiation Request - Response Largely depends on lower layers (SSL / TLS) Web Sockets Full duplex communication over TCP Low latency, high performance web applications Above TCP Uses HTTP for initial handshake JSON, etc. Full duplex communication same over TCP socket. TLS DDS Data centric model (Virtual) Global Data space and broker-less Peer-to-Peer model Several segments such as health care, factory, UAVs, Asset tracking, etc Can run over UDP, TCP, shared memory and other transport types DSSI defines a standard data format based on extension of Common Data Representation Named topics, user defined data types Real-time Publish- Subscribe TLS and some OMG specific security methods Vendor specific extensions also available XMPP Availability for Concurrent Transactions (ACT) style for carrying out asynchronous end-to-end exchange of structured data Instant Messaging and Presence Applications, Jabber XML, EXI SASL, TLS, lower layer security Source from TR-0009

OMG DDS Standard Introduced in 2004, DDS is a standard for Real-Time, Dependable and High Performance Publish/Subscribe DDS behavior and semantics can be controlled via a rich set of QoS Policies DDS is today recommended by key administration worldwide and widely adopted across several different application domains, such as, Automated Trading, Simulations, SCADA, Telemetry, etc.

What is DDS? Data Distribution Service Real-Time and High-Performance Data Communication Service Publish/Subscribe Model Various QoS Support No Essential Broker Data Centric Publish/Subscribe(DCPS) Ownership Durability Content Subscription Object/Relational Mapping UDP/IP Application Data Local Reconstruction Layer(DLRL) Object/Relational Mappling RTPS CORBA

DDS Communication model QoS QoS Data Writer Data Reader DDS DOMAIN QoS QoS QoS Data Reader Data Writer QoS Topic B Topic A QoS Data Reader QoS Data Writer QoS QoS Data Reader Topic C QoS QoS Data Writer QoS Topic D Data Reader QoS QoS Data Writer Data Reader

Topic Topic Unit of information atomically exchanged between Publisher and Subscribers. An association between a unique name, a type and a QoS setting

QoS Contract QoS: Durability QoS: Deadline QoS: Latency Budget GDS QoS: Durability QoS: Deadline QoS: Latency Budget QoS: Liveliness QoS: Reliability …..

Industrial Internet Consortium DDS is a strong candidate for IIC protocol

Other Communication Protocol Why DDS? DDS Everywhere Android Embedded OS DDS Other Communication Protocol (MQTT, REST, etc) Enterprise OS Reference : OpenSplice DDS Intro http://www.omg.org/hot-topics/documents/dds/Prismtech_Slideshow.pdf

Why DDS? DDS Usage Increasing

oneM2M Configuration ADN MN IN ASN RTPS(Broker-less P2P) or DDS (DCPS) DDS (DCPS) DDS (DCPS) DDS (DCPS) RTPS(Broker-less P2P) or CORBA(Broker-based)

oneM2M Message Binding oneM2M Primitive oneM2M Primitive Operation and Parameter Data Reader/Writer Data type and Mapping Data Reader/Writer Topic Name DDS DDS UDP/TCP UDP/TCP IP IP

Connecting Nodes Topic Naming Similar to MQTT as one option “oneM2M/req/AE-ID/CSE-ID”(sample) AE Writer Domain Reader CSE Init Init Publish Subscribe <oneM2M/req/AE-ID/CSE-ID> <oneM2M/req/AE-ID/CSE-ID> Read

Primitive Serialization Message (DCPS) Header 1:1 Submessage 1:n

QoS Processing DDS QoS oneM2M CMDH message Event Category Request Expiration Timestamp Result Expiration Timestamp Operation Execution Time Result Persistence .. DDS QoS Durability Reader Data Life Cycle Writer Data Life Cycle Lifespan Reliability Deadline Latency Budget Transport Priority …