Re: [opendds-main] TCP communication between eProsima FastDDS and OpenDDS

[Adam M. <mi...@ob...>]

Hi Charles,

On 6/16/2020 8:40 AM, Charles Kalleppally wrote:
>> Am 16.06.2020 um 14:58 schrieb Adam Mitz <mi...@ob...>:
>>
>> No, the only standard for interoperability is using rtps_udp as the transport.  You can also do this in the cloud.
> Are you referring to have a RTPSRelay running on FastDDS side and on the cloud side as well (the publisher is communicating via public internet)? Is the communication between the RTPSRelays using UDP? I have not checked that option, respectively I was under the impression that is OpenDDS implementation specific.

Standard interoperable DDSI-RTPS (when used for both Discovery and Transport) can work in the cloud.  Making it work means overcoming various limitations and barriers to standard UDP/IP traffic that cloud infrastructure puts in our way.

Which limitations you need to overcome (lack of multicast, payload size restrictions, NAT firewalls, etc.) will depend on how exactly you're deploying it.

Some resources for background info:
- DDS Foundation Panel (webinar recording) https://www.brighttalk.com/webcast/12231/402845
- Chapter 15 "Internet-Enabled RTPS" of the OpenDDS Developer's Guide 3.14
- Multicast repeater tool https://github.com/oci-labs/cloud-multicast-repeater
- https://objectcomputing.com/resources/publications/sett/march-2019-multicast-to-cloud-for-dds-applications
- https://objectcomputing.com/resources/publications/mnb/interoperable-internet-enabled-dds-applications

If you decide to use RtpsRelay (wouldn't be necessary in all cases), it would not be limited to relaying traffic that originated from OpenDDS.  We haven't tried that scenario so we'd be interested to hear how it works for you.

Thanks,
Adam Mitz
Principal Software Engineer, OpenDDS Tech Lead
Object Computing, Inc.