what is sccp called digits in ss7?

Question

i have a query select count(distinct imsi) from SS7 where sccpcalleddigits like '86133%' . what does this sccpcalleddigits mean? I am completely new to this domain.

Answer 1

It is simply the called party digits - i.e. the number that is being called.

I am guessing this is clear but just for completeness - if Ann calls Bob, Ann's number is the calling number and Bob's is the called number.

More detailed:

SCCP includes a 'Called party address' and a 'Calling party address'.

These both have similar formats and can contain different information in different circumstances - from the ITU spec (Q.731 - you can usually find a PDF copy with a web search). The high level structure, from the ITU spec is:

The address indicator part is defined:

The "address indicator" indicates the type of address information contained in the address field (see Figure 4). The address consists of one or any combination of the following elements:

– signalling point code;

– global title (for instance, dialled digits);

– subsystem number.

So, assuming you mean by 'called digits' what the spec refers to as 'dialled digits' these are the number being called as above.

An SCCP called/calling address support multiple formats so if this is not what you are referring to then it might be worth looking at the 'Called Party Address' section of the spec for more background.

Answer 2

SCCP is one of layers in telco protocols stack used between telco exchanges (more precisely in this case - as we have IMSI - it must been a mobile MSC or HLR). So SCCP Address (in this case - Called Digits) is more an address of the target MSC rather than a number of Ann (but IMSI number could be hers).