Time between 2 tries [mins]
This specifies the number of minutes between each attempt to resend the transaction.
For example, if a transaction were sent to an external system that did not exist or was not available at the time the transaction was sent, a batch job would be scheduled to resubmit the transaction at a later time. If the value for (b) is 5 and the value for (c) is 10, then the job would be scheduled to run every 10 minutes up to 5 times. At the end of this time the transaction would have to be manually restarted from the tRFC queue (or a batch job to execute it would have to be set up manually).
If these values are not set for the specific RFC Destination, the default values for (b) and (c) are typically 30 and 15 respectively. This means that the default behavior for a failed job (due to connection or time out problems) is to reschedule itself to run every 15 minutes for up to 30 attempts.
You can see the time the batch job is rescheduled to run in sm58. This is the time column on each transaction line. This time is first set to the original submission time of the transaction. If the transaction is scheduled as a background job, this time is updated to be the start time for that job. To see more information about the scheduled job, select a transaction line and choose Information > Display Planned Jobs from the menu.
Remember that the timing values for retry of a transaction determine only when the batch jobs are scheduled to run. A scheduled batch job may not run at the scheduled time, but may run later than this, depending upon the load in SAP and parameters set on the type of job submitted. This can create a very slow transfer of information out of SAP, causing IDOCs to appear in the Siebel application, possibly many hours after they were first created. It is more efficient to schedule your own jobs for the resend of failed transactions.