Connectivity Framework Annex A: Assessment Template: DDS
A. 6.4 Functional Viewpoint A. 6.4.2 Core Transport Layer Functions
Messaging Protocol( Section 5.1.1)
Communication Modes( Section 5.1.2)
Endpoint Addressing
( Section 5.1.3)
Connectedness( Section 5.1.4)
Prioritization( Section 5.1.5)
Timing & Synchronization( Section 5.1.6)
Message Security( Section 5.1.7)
Does it require UDP or TCP? What are the salient aspects of the messaging protocol? What are the message size limitations? What are the usage assumptions? Is it optimized for certain message requirements?
The DDS messaging protocol( DDSI-RTPS v2.2) assumes connectionless( UDP) messaging. The messaging protocol can allow messages larger than the UDP( 64kB) limit. The protocol is designed to support widely varying message sizes.
DDS implementations can also support TCP. There is an ongoing effort to standardize the mapping under the auspices of the TCP / IP DDSI-RTPS specification. Which communication modes does it support? DDS supports both unicast( default) and multicast( when available).
Describe the transport endpoints. How are the endpoints addressed? What are the limitations, if any, on the number of endpoints?
DDS transport endpoints correspond to a DDS-DataWriter and DDS-DataReader. The endpoints are addressed using a globally unique ID( GUID) for the endpoints. The number of endpoints within a domain is bounded by the number of unique GUIDs. Does it require a connected circuit between the endpoints? Summarize the salient aspects.
No, DDS does not require a connected circuit between the endpoints. Does it provide a means to prioritize messages? Summarize the salient aspects. Yes, DDS provides a means to prioritize messages. Does it provide the ability to synchronize time? Summarize the salient aspects.
No, DDS does not provide a way to synchronize time between endpoints. In systems using DDS, this is typically accomplished using a separate time synchronization protocol. Does it provide mechanisms for message security? Summarize the salient aspects.
Yes, DDS provides mechanisms for message security. It provides support for authentication of endpoints, message encryption and message integrity.
IIC: PUB: G5: V1.0: PB: 20170228- 68-