The greater the volume of traffic, that is the higher the rate of journal entry deposits, the faster communications method you must choose. If your traffic is minimal, then a slower communications method can be adequate.
The delivery mode defines how journal entries are replicated to a remote journal. The delivery mode only applies when actively replicating the journal entries from a journal on a source system to a remote journal on a target system. The delivery mode can be either synchronous or asynchronous.
If the application dependent data is critical and the loss of journal entries can impact your business, then use the synchronous delivery mode. Synchronous delivery mode is only valid when activating a remote journal that is associated with a local journal.
It may be acceptable that the remote system does not have all the journal entries as they are being deposited or replicated into the source journal. If this is true, the asynchronous delivery mode is a good choice to minimize the impact to the source journaling throughput.
The choice of delivery mode and communications protocol are closely linked. Since the synchronous delivery mode will affect the interactive users response time, the faster the communications protocol the better. This again will be dependent on the journal entry deposit rate.