[Kamailio-Users] prepaid system

[Daniel-Constantin Mierla]

On 12/31/08 16:09, Luciano Afranllie wrote:
> On Wed, Dec 31, 2008 at 7:44 AM, Daniel-Constantin Mierla
> <miconda at gmail.com> wrote:
>   
>> Hello,
>>
>> On 12/30/08 14:23, Luciano Afranllie wrote:
>>     
>>> [...]
>>>
>>> I don't know if this has been discussed earlier but it would be nice
>>> to point some key requirements for a system supporting prepaid users
>>> and possible solutions to those requirements.
>>> I think several of us is doing the same things so, we can benefit from
>>> other experience and may be we can find a pattern (of course not
>>> perfect and "fit all") for this problem using open source
>>> alternatives.
>>>
>>> I am talking about something like this:
>>>
>>> - How to store and retrieve user category (postpaid, prepaid, etc).
>>> LDAP, Radius, SER groups?
>>>
>>>       
>> this is usually up to what you are more familiar to. If you go for sql-db
>> system, then you should have in consideration the load_credentials feature
>> provided by auth_db module. With that you can load attributes per user at
>> authentication, saving one extra db query.
>>
>> As I am designed now my systems, I have dropped a lot of modules that were
>> hiding behind sql queries, by using config file operations (via
>> avp_db_query() and now, with trunk, via the new sqlops module). In this way
>> I am not stuck to a predefined db structure and can use tricks that make the
>> sql operation faster based on server side features. sqlops module makes
>> possible to load caller and callee profiles in one query for each and keep
>> them for entire route processing in memory, therefore, very fast access.
>>     
>>> - Callflows
>>>
>>>       
>> Usually there are two scenarios
>> 1) caller ----- proxy ----- b2bua ----- proxy ----- callee
>> 2) caller ----- proxy ----- b2bua ----- pstn ----- callee
>>
>> First is when you do prepaid for voip-to-voip and you deal with NAT, also
>> when you have kind of sbc for the second proxy. The second is the typical
>> case for calls terminated to pstn.
>>
>>     
>>> - What IVR to use for user notifications (no credit, etc) and user
>>> balance check?
>>> Asterisk, SEMS, etc?
>>>
>>>       
>> I use most of them. I go by default to Asterisk or FreeSWITCH, depending if
>> it a more PBX-like service or carrier. SEMS is something I used a lot in the
>> past.
>>     
>>> - How to enforce call tear down when credit is exhausted?
>>> What B2BUA to use?
>>>
>>>       
>> B2BUA, all listed above are good options in certain conditions. The most
>> important aspect is to understand scaling vs features requirements.
>>
>>     
>>> - How to manage recharges?
>>>
>>>       
>> Voucher cards + IVR is an option. Payment gateways (for credit cards) +
>> their API.
>>
>>     
>
> Thanks Daniel for your ideas.
>
> I just have a doubt about call flows (I made this question in another
> thread but still it is not clear to me).
>
> My understanding is the call comes into the proxy and it decides to
> send the call to the b2bua if the caller is a prepaid user.
> My question is, should the b2bua or the proxy make the final routing
> decision? How does the b2bua know where to forward the call next? If
> we use routing capabilities of the b2bua then we loose the ability to
> use routing capabilities of the proxy.
>   
use the routing capabilities of the proxy. B2BUA can use the R-URI or 
certain headers added by proxy to decide where to send.

Daniel

> Another approach I am thinking is one b2bua per destination so, if I
> want to fw the call to gw01 then in the proxy I fw the call to
> b2bua01, if I want to fw the call to gw02, then I fw the call to
> b2bua02 and so on.
>
> Regards and Happy new yer for everybody!
> Luciano
>
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>   

-- 
Daniel-Constantin Mierla
http://www.asipto.com