smsbox to bearerbox ack / nack

Hi,

I have been doing some investigation into tighter integration of my  
application with kannel. As such I have been writing some  
applications that communicate directly with bearerbox, connecting to  
the smsbox port. For sake of simplicity lets call my app mysmsbox.

What I noticed was that when a message is sent from bearebox it stays  
in the storefile until an ack is sent back. This is great if mysmsbox  
dies before it has done processing the message.

But I also notice that if you send ack_success or ack_failed back to  
bearerbox it seems to make no difference.

Ideally I think it would be better if you sent back ack_failed for  
bearebox to requeue the message (possibly after some small time  
delay). This way if you were unable to process the message for some  
reason a different mysmsbox has the chance to do it. Under the  
current situation you have to wait for the current box to be in a  
situation where it can now process the message, or it needs to  
restart in order to allow another mysmsbox a chance.

In the situation where you only have 1 smsbox type app connected it  
really makes no difference. But if you are looking for a more  
resilient solution then multiple smsbox apps on different servers is  
the way forward, but only if you have a way of failing messages over  
from one smsbox to another.

I'd be interested in peoples comments, and how easy they think it  
will be to implement.

Regards

Ben