[OpenSER-Users] Can openser auto-retry if a call fails?

Hi, I know this kind of function exists in Asterisk, but I want to know if Openser can do it as well. Let's say there are two fail-over numbers(DID-b,DID-c) that associates with a DID(DID-a), if the original number(DID-a) that get dailed can't rearch the destination due to BUSY, NO RESPONSE, etc, is there anyway of having Openser to auto-retry with the next DID(DID-b)? If the next one fails, try the next next one(DID-c). One way I can think of is to do a lookup from DB for the alias in the fail_on_route section, but if I have multiple aliases, then I will have no way of *remembering* which alias has been tried unless I store it in the DB which is not a good solution. I am wondering if there any other way of doing it? Thanks in advance for all your kind suggestion. Regards, Pete