EMS vs RV

• EMS is server based while RV uses a communications daemon on every machine.
• Depending on the requirements for speed and bandwidth, flexibility, security,reliability, availability and message passing between sub-nets one might require EMS or RV or a hybrid of both. 
• Both TIBCO RV and TIBCO EMS provide authentication, authorization and secure communication. Tibco RV and TIBCO EMS both provide secure socket layer (SSL) support for all communication. Where Web access is used, HTTPS is supported as well.
• In conclusion the EMS (JMS) hub-and-spoke model provides a better choice for the majority of EAI problems and RV is best left to its niches: high volume, high performance, 1-to-very many. 
• Generally use RV for speed topic / broadcast messages and EMS / JMS the more you are worried about assuring messages get to a receiver.  
• You can tune both products to go faster and more reliable. RV is basically broadcast via UDP, so needs RV Remote Daemons to cross subnets. You can bridge EMS to RV if you have specialised areas which you want to speed up.