Wrong CLI

I have had that happen several times when the call is coming from mobile network to landline or vice versa.

Two instances, my sister on Vodafone network phoned on the landline and the CLI that came up was not her’s. I telephoned the CLI number that came up and the the user (a man answered) was shocked to find his number being used. He was also located in different part of country. However, the part of the country this man was located was fairly close to where my sister was located.

The second was a landline CLI that kept ringing my mobile. Eventually I rang the landline CLI and a woman answered phone. I informed her her number was ringing my mobile. She became worried as she said she had been away for several days and had onoy been back 30-minutes before my call to her landline. Spooky.
Point of interest the part of the country she was located I had been in that area some two days before folowing christmas holiday.

In my experience I didn’t see a fixed line calling another fixed with a wrong CLI. because the message is carried in IAM message in SS7 or SETUP message in the PRI protocol. The problem is with the mobile network where most of the confussion comes from, call forwarding can greately effects the CLI. Sometimes, a loop of call forwarding is created and passing through dozens of trunks, some trunks have a parameter which eats away the first two digit that might be the area code, so the called can see the calling number without the area code. This is exactly what happened to a network, have you ever seen a CLI 22 OR 1. This can be avoided by a parameter in the HLR which is MAXIMUM call forwarding times. Beside, if there is a problem with the CALLING LINE IDENTIFICATION PRESENTATION(CLOP)it can also bring this problem. The function of this CLOP is to indentify to whom you are actually connecting. For example subscriber A dails subscriber B, and B is forwarded to C. After C answers the call from A the displaying number in A mobile phone is changed to subscriber C. So you can identify that B has forwarded you to C.
One day, one of my co-works was having a relationship with a girl and suddenly they broke up, and he stopped answering from her number, another guy also knew about the story, he took the mobile phone from my co-worker and he saved her number 746466 with the name 789948. That means everytime she tries to call her boyfriend number,this number 789948 displays on his phone. which he actually don’t know about this number. After he answers the call he turned back with a red face saying “its her what shall I do, I don’t wanna talk to her, by the way what happen to the mobile network. Because if he dail both numbers 746466 and 789948 the same lady will answer, I was responsible for the NSS part of our network so I checked if both numbers have some Call forwarding number activated, but there was no services. I got confused but after a long thinking I called my co-worker and told him to bring me his mobile phone and I checked the contacts menu and I found out that trick.

The called party number for CLI services is carried in IAM message (ISUP), but the carriers are not forced to send it, only if there´s commercial agreement for this. A call can be successful despite the wrong CLI services.

As Mr.Pix said the CLI is controlled not completeky by HLR but by the Gateway MSC’s wheerin the CLI can be tampered with the number of digits.The Network can be receive a call from International Network operators and route the call as a local call by using the Basic Trunks and display its own CLI.

Thks

the element configuration in ericsson with prefix of operators specific is for carrying out the call from ur GMSC. But the actual calling number is tampered by giving its own digits populated.

thks