Hi,
I am a manager so forgive me for my non technical question.
We have implemented a SNMP server on our systems. These are 30 systems distributed around the US. When all systems are connected to the same router, they can communicate fine -- that was in our test lab. Now my programmers tell me that they cannot 'easely' get the systems to talk over the internet using a router at each location because the routers cannot resolve the addressing. There is a mismatch between private LAN addresses and internet addresse.
They tell me that since DDS is a publish/subscribe protocol, it overcomes the problem. I keep reading on DDS and it seems very well what we need, but I cannot figure out how it fixes the address resolving issue. Can someone explain to me what I miss?
Thanks for taking the time,
Patrick
Hi,
At a high level this has to do with how the different protocols discover the physical addresses of the different systems that need to communicate. In the case of SNMP I am not sure how this is being resolved. I know that in some cases it uses multicast, which would not be routable on the public WAN, or perhaps it was being configured explicitly via the IP addresses (which may change on the WAN depending on how the system is deployed), or maybe it was being resolved by DNS based on some domain names...
In addition, there can be a problem for SNMP if your systems are deployed inside private networks which are then connected to each other via the public Internet. In this case, your systems are likely sitting behind firewalls/NATs and may have private addresses that are not routable on the Internet.
DDS "solves" this because it has a discovery protocol and various mechanisms to allow applications to communicate even if they are behind Firewalls/NATS. Depending on your actual deployment you may need to configure additional DDS discovery service and transports. Or configure your firewall to allow traffic on certain ports. But these mechanisms are already available as part of the RTI Connext DDS SDK. Many of our customers use them.
I would recommend you would get in touch with one of our Field Application Engineers who can take a look at your specific deployment and advise what you would need to do to make it work using DDS.
Gerardo
Hello Patrick
My name is Bert Farabaugh, and I am a Field Applications Engineer with RTI. My email address is bertf@rti.com. Please send me a note whenever you get a chance and we can setup a time to discuss your application. I would love to see how we could help solve your problem.
Thank you,
Bert