OSB transaction required

The advantage of setting "transaction required" for your Proxies is that the incoming request will be starting a transaction and set the default <con:qualityOfService>exactly-once</con:qualityOfService> , instead of <con:qualityOfService>best-effort</con:qualityOfService>. You can examine the $inbound you will find this setting.

Subsequent Publish or Route will use this same Quality Of Service, instead of the default which is "best-effort".