Answer to L.T.T. – 09

This month’s LTT by Guy Howie was meant to illustrate the importance of assuring destination dial codes, their descriptions, and the associated rating charges and internal rating system logic.  The trick is to be able to validate and spot errors in the detail, even though the margins can look good.

Identifying what went wrong in Call Rating – How well did you do ?

  • In the first example, the charging mechanism was being applied incorrectly – customers were being overbilled because the duration element of the charge was being applied immediately instead of after the first 60 seconds as advertised. This type of error can easily arise from misunderstandings between IT and the Business.
  • In the second example, the rate applied was 1 pence per minute instead of 10 pence per minute – a simple error, perhaps caused when keying in a rate and getting the decimal point in the wrong place.
  • The third and fourth examples were rating correctly, with the fourth example illustrating that negative margin calls can be a natural consequence of ‘free/ bundles minutes’ type packages, and the values of these should be monitored.
  • The fifth example shows how the losses can grow when there is an error in the dial codes, for example when the minutes are to a more expensive Poland International Mobile destination but the dial code has not been setup in rating.
  • In the sixth example, we see a common situation where the calls to new country, in this case to Sint Maartin, are rating as USA calls because the Sint Maartin Dial code was not set up in rating. The USA often has a default code in call rating like “001” – this means all 001 terminating traffic not set up correctly will rate as USA traffic!

Finally, we see a current area of pain for operators in the last example – where some destinations are being classed by International Carriers as ‘Mobile’ or ‘Special’ because of issues like numbering abuse and International Revenue Share. In the world of retail, the calls are often referred to as fixed line and so losses can arise.

The above examples are all real life examples which we at BIAAS have seen more than once. Congrats to Arun Kapoor and Michael Lazarou for providing by far the closest and most comprehensive answers.

The next LTT will be published on Monday 21st October.


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