Do you know what a
Phone Number is?
Are you sure? Did you say something like?
“It is a number used on one phone to connect to
another phone”.
As far as it goes,
that is correct, but that is only one of several correct answers. You could
have answered the question by saying any of the following and also be right
because phone number pops up all over the CSP’s business, but spotting it can be a bit like
playing “Where’s Wally” (or “Where’s Waldo”, if you
are American).
What is a phone
number?
a)
A phone
number is a string of digits and is not, in its truest sense, “a number” because
any leading zero is significant.
b)
A phone
number is something that can be bought or sold and quite significant amounts of
money can be paid for phone numbers. According
to The Register (www.theregister.co.uk) the world's most expensive phone number
was auctioned for charity on 22 May 2006 in Qatar. The number, 666 6666, sold for 10m Qatari
riyals or £1.5m.
c)
A phone number
is asset allocated to the Communications Service Provider (CSP) by the telecoms
regulator that is then allocated, sold, lent or in some other way given for the
use of a customer (see (a) above). The
customer can, often, take the phone number with him when he leaves the CSP; he
can “port” it out.
d)
A phone
number is a way of contacting people and/or organisations (the “simple” answer);
so it is a type of address.
e)
A phone
number is information on how to connect two phones during a call.
f)
A phone
number is a service identifier; a phone service is identified by the phone
number used by that service.
g)
A phone
number is an account identifier; the customer's account or sub-account is identified
by the phone number, after all it appears on the bill.
I’m sure
there are other answers too, but the list shows that there are quite a few
different definitions a phone number and that it should be found in quite a
number of different “pictures” that illustrate the CSPs business.
In the CSP world we
have the Frameworx Information Model (aka the SID) that provides definitions of
important business concepts and provides lots of “pictures” or data models that show how these concepts
interrelate. So let’s start
searching for Phone Number in the SID.
The SID is full of entities and relationships so looking for a
particular entity really can be a bit like reading “Where’s Wally/Waldo”;
looking for what should be something really easy to spot, but that just doesn’t stand
out from the crowd.
SID experts know, even
though the SID but doesn’t explicitly show it, that Wally (the phone
number) can be found disguised as a Logical Resource and as the Logical
Resource can be provided through a Product we can claim to have found him for pictures
(a), (b) and (c).
The SID actually has phone
number in it as (d), a “Contact Medium”, used to contact Customers, so this time Wally
wasn’t
even disguised but because it doesn’t relate this phone number with the (Logical
Resource) phone number of the Product the Customer is using to make phone calls
on the CSPs network it wasn’t particularly easy to find.
So can we find the Phone Number in the SID doing the job defined in (e),
providing information on how to connect two phones? Mr Strowger’s mechanical exchange invented about 125 years
ago used a phone number to automatically route the call from one phone to
another. Mr Strowger was an undertaker
who became convinced that the telephone operator who was the wife of a
competitor undertaker was forwarding calls to her husband when people called
for an undertaker, and so he dreamt up a way cutting out the operator in
connecting two phones together. CSPs still use this fundamental mechanism in
one way or another to route calls using the information imbedded in the phone number
to work out how to find the phone that is being called. This is very important for OSS/network operations
but it also has a direct impact on the amount charged to a customer for the
call and the profit made by the CSP (on net, off net, roaming, roaming
partners, etc, etc).
So we would expect to find Wally/Waldo (the Phone Number) somewhere
around the network picture even if it seems to be bit of an obscure area to
find him/it. But, actually, how obscure
is this picture? Let’s face
it, the two of the most important fields on a CDR are the “A Number” and the
“B
Number” – phone
numbers and Billing wouldn’t work if these didn’t
identify the product/service being used and ultimately the pricing, discounting
and allowances to be applied to the customer’s account for the usage of the network.
Search as you may, you won’t find Wally/Waldo here in the SID.
And finally, and perhaps most importantly, all the CSPs I’ve
worked with all talk about the phone number as being the identifier for the
user/the subscriber (a legacy concept
that isn’t
in the SID) or the product (the subscription
or price plan (two more legacy
ideas quite rightly excluded from the SID).
But this isn’t just a bit of “legacy thinking” which is how I used to dismiss this
definition. There is an important idea
here –
not all Products are equal – there are the “subscription products” or the “contract
product”
that define the overall (basic) services (e.g. voice, messages and data) and
their prices and allowances while there are other add-on products that are then
associated with or ‘bolted on’ to the main product – and the
main product, nine times out of ten, is identified by the Phone Number by both
the Customer and the CSP.
The SID doesn’t draw Wally/Waldo into this picture either,
though the ever-flexible SID experts (like me) can claim he is there, you just
can’t
see him!
I don’t
think we should let Phone Number hide in Logical Resource whilst also living
secret lives as Contact Medium, Product, Service Identifier and Network Address
–
these different nuances of the phone number’s role need to be explicitly stated.
We should be able to see Wally/Waldo wherever he is, then when someone
who has never seen the SID before says
“Wow!
That looks complicated… Let’s start with something easy; show me where in
these diagrams Phone Number is”,
you can point confidently to the model and say
“There!”
rather than waving your hands around talking about rather complicated things
called Logical Resource, Resource Role, Involvement Role etc etc and conducting
the “Where’s Wally?” hunt.
You may ask,
“How can I make the SID representation of Phone
Number a little closer to the business view of Phone Number?”
or perhaps, if you will,
“How can
I put Wally in SID?”
If you make the following enhancements to your own in-house
implementation of the SID then it will reflect the business realities and
define phone numbers in a way that everyone can recognise and relate to and you
will able to point confidently to the SID and say “There’s Wally/Waldo”.
- Put PhoneNumber and PhoneNumberSpecification into the SID as concrete subclasses of Logical Resource and Logical Resource Specification respectively
- Create an association from Contact Medium (Phone) to this class.
- Create concrete subclasses of Product Offering and Product as “Contract Product Offering” and “Contract Product” to identify these key products.
- Create an association from Contract Product to Phone Number “identified by” to acknowledge that this is important relationship.
I know that the last step is a little controversial for “dyed-in-the-wool” SID
practitioners as this is information is already provided by the multipurpose ProductInvolvementRole. This is a sub type of InvolvementRole that is
played by a CustomerAccount, or a PartyRole, or importantly a
ResourceRole. As an alternative to step
4 the creation of a concrete subclass of ResourceRole called “IdentifyingPhoneNumber” would
keep the purists, if not the business and “Wally hunters” happy.
So Phone Number is a lot of things to a lot of different people and many
of these are already in the SID if hidden from view – but one
thing is for certain it isn’t just a string of digits or just a Logical
Resource.
So, now, where are Wally’s friends IMSI, IMEI and MSISDN hiding in the
SID?
