Re: splitting messages

Jeetendra Singh wrote:
>  
> 
>     Because of billing issues. We do this with the operator NetCom in
>     Norway. The
>     price is set as the originator in the first message, the remaining
>     messages
>     have originator=00.
> 
>     I made a private patch to Kannel that take care of this, and it
>     really does
>     works fine. However, it may be Netcom changes the originator on
>     their side
>     after sorting out the billing - just a thought.
> 
> Interesting!!! Do you mean NetCom will charge for only a single message 
> if all the messages originated from my gateway contains same originator?
> -Jeetendra


The actual problem lurking under all this is that bearer-based charging 
doesn't work very well for concatenated SMS. There isn't a really 
acceptable solution.

Consider the case where the first message in a Nokia PM (with the magic 
"charge me" flag set in the sender address) arrives, but the follow-on 
packets don't. There you have the worst of both worlds, as the customer 
will be charged for content they will likely never even see.

One solution I have seen implemented is the following variant of the 
receipt SMS solution -- where a second charged text message is used to 
tell the billing system that all parts of the message have been sent.

MS			ESME
   ---------(MO)--------->    ; Request for service

   <--------(MT)----------    ; Part 1 of content
   ---------(DLR)-------->    ; Part 1 delivered OK?

.
.
.

   <--------(MT)----------    ; Part n of content
   ---------(DLR)-------->    ; Part n delivered OK?

   <--------(MT)----------    ; Charged MT, sent if all parts OK.


Add the appropriate error handling, and you have a very complex and slow 
download server that is guaranteed not to cheat the user.

As a side note: if the receipt needn't be visible to the end user, then 
a simple mechanism could use the protocol_id value 64 (decimal) for the 
charged MT. This is the dreaded "PING" SM (a/k/a "Replace Message Class 
0") which is neither displayed nor stored on SIM on most handsets.

Another note: the MO request is MANDATORY. Consider a prepaid customer 
that has fallen below whatever balance the operator considers minimal to 
use SMS. In that case, the customer will have SMS MO barred, and will 
not be able to initiate the transaction.

David WHITE
ONE GmbH