VOIP Transfer

[AchmatK]

I'm not very technically inclined but managed to configure my SIP VOIP account to make all calls for free for the past 6 months and wanted to know if its a problem the my sip service provider knows about or can it be done with other sip services providers.

At the moment I will not say which sip provider I am using.

What I have is a sip account with a South African company and they provided me with the standard 087 number.

I have loaded SJ Phone which is a windows softphone on my PC as well as on my cell. I then entered all my account details into the relevent field in order to make and receive voip calls either from my PC using my ADSL connection or using my cell with 3g.

SJ Phone has a feature that allows all calls to be diverted to any other number. So if some one calls my 087 number, SJ Phone will divert to any number that I specify without charge. I sip service provider does sell vouchers to use with the service but I have not needed to use these vouchers with this diversion in SJ Phone.

What I have also managed to do was have both my pc softphone and cell softphone on at the same time. I would then use the pc softphone and call my own sip 087 number which is diverted to my cell. After I answer my cell, I can then transfer the call on my pc softphone to any number without paying for the call.

I know this sounds a bit complicated to make a call this way but it takes an extra 10 seconds to make a call that is effectively free. I reccently had to call a client in the UK and used this system. The call lasted more than an hour and was on my cellphone and my prepaid account with my sip service provider was not debited with any amount for the call.

What I would like to know is what happens to call which originates from a sip account when you divert the active call to a normal number?

I have tried below to do a diagram of what I am doing.



087 Sip account calls normal 082 123 4567
Softphone diverts active 082 call to 083 765 4321
087 call is terminated and current active call is 082 --> 083 on normal cellular network

 

[s0lar]

Sneaky sneaky, it reminds me of a call-center agent who figured when the manager was not at his desk he would quickly put a call diversion on to a international number at his managers desk. Run back to his own desk call his managers internal extension once the call was bridge he unset the diversion. CDR's showed the manager was abusing his privilege to which he swore he had no part. 100+ calls a week to Zimbabwe. Yes, the agent he lost his job in the end.

The operator will eventually wisen up to this, dont be surpised when you get the bill.

 

[gmza]

The service provider is probably using Asterisk as their soft-switch without the correct parameter to ignore forwarding requests from the client device.

The CPE device/softphone generates a SIP 302 response.

The CDR will log original call details and SP will bill accordingly, causing the SP to be out of pocket.

I suspect that there are quite a number of SPs prone to this. It's an easy oversight to make and one that is likely to fall under the radar up until the point where someone gets greedy and exploits it too heavily. At that stage, the SP's billing recons will go horribly out and they will likely start investigating.

Word of caution: many SPs include in their terms and conditions clauses that allow for billing adjustments where errors are found within a defined period.