17/04/2023 Page 1 of 4

SIGNAL Doc 18_019

BOICexHC for SMS

Meeting Name & Number: SIGNAL # 18

Meeting Date: August 17th, 2004

Meeting Location: London GSMA Office

Document Source: Vodafone D2

Document Creation Date: August 11th, 2004

Document Status: For Approval

For Information

For Discussion X

Associated Knowledge Base(s): Short Message Service (SMS)

Circulation Restricted *: GSM Association:

Members X

Associate Members X

Document History:

August 11th, 2004 Draft Version

N.B. All GSM Association meetings are conducted in full compliance with the GSM Association’s anti-trust compliance policy

High Level Document Summary:

This document contains a description of fraudulent usage of SMS-Cs when BOICexHC for SMS is not supported by VLR and SMS-C is open.

*Restricted – Confidential InformationAccess to and distribution of this document is restricted to the persons listed under the heading Circulation Restricted. This document is confidential to the Association and is subject to copyright protection. This document is to be used only for the purposes for which it has been supplied and information contained in it must not be disclosed or in any other way made available, in whole or in part, to persons other than those listed under Security Restrictions without the prior written approval of the Association. The GSM MoU Association (“Association”) makes no representation, warranty or undertaking (express or implied) with respect to and does not accept any responsibility for, and hereby disclaims liability for the accuracy or completeness or timeliness of the information contained in this document. The information contained in this document may be subject to change without prior notice.

© Copyright of the GSM MoU Association 2003

GSM Association Restricted Confidential Information

Table of Contents

1 Scope of the document................................................................................................................. 3

2 Problem Description.....................................................................................................................3

3 How to avoid it............................................................................................................................... 4

GSM Association Restricted Confidential Information

1 Scope of the document

BOIexH SMS is frequently used to stop prepaid customers to send SMS through other SMS-C than the home SMS-C while roaming in Camel1 networks. On-line charging is usually done via a payment platform that connects the SMS-C with the SCP. After successfull credit check the SMS is delivered by the SMS-C.BOICexH for SMS Supplementary Service is a standarized service. However experience has shown that when an HLR sends this service down to a foreign VLR within the Location Update procedure, the service will be accepted, but in some cases the functionality for BOICexH analysis is not given in the VLR and the barring will not be carried out.

2 Problem Description

The below graphic and message flows illustrate the normal (1.) and fraudulent (2.) case.

(1.)

SS BOICexH for SMS is a standarized Service, so it seems like no VLR has problems to accommodate it in the customers record. But when it comes to the functionality of this barring type, not all VLRs may perform the barring correctly.In this case the prepaid customers while roaming are able to send SMS for free over 3rd SMS-C´s that are open to anybody (SMS-C that don´t check if the user is an own customer) without any on-line charging taking place. Precondition is that Mobile Network B is already a roaming partner of the HPLMN and therefore the routing will work.

IGP

MSC / VLR

STP

HPLMN

HLR

IGP STP

VPLMN = Mobile Network A

SMSC

C7 CARRIER

SMSC : Short Message Service Center

HLR : Home Location RegisterIGP : International Gateway PointBSS : Base Station Subsystem

SMSC

Mobile Network B

IGP

BOICexHC for SMS

MAP «Forward Short Message / SMS Submit

TCAP End « Forward Short Message / SMS Submit

MO SMS

SMSC HPLMN

BSS

HLR

MT SMS

SCP

SCP

Credit check procedure

Mobile Network A

Credit OK & charging

HPLMN

MAP «Send Routing Info for Short Message

Forward Short Message / SMS Submit TCAP End «

MAP «Forward Short Message / SMS Deliver

Forward Short Message / SMS Deliver TCAP End «

MSC / VLR

GSM Association Restricted Confidential Information

2.)

The commercial damage will occur for the HPLMN: when the roaming prepaid customer uses a 3rd party SMS-C the HPLMN is not able to charge him for the SMS. However the owner of the 3rd party SMS-C (Mobile Network B) will charge the VPLMN (Mobile network A) based on the TAP record created in the SMS-C. The VPLMN (Mobile Network A ) in turn charges the HPLMN based on the TAP record for SMS MO created in their MSC and containing the A-party address.

3 Solution

The described problem can be overcome with 2 actions:

1.) the VLR shall carry out the BOICexHC for SMS function by number analysis for SMS barring

2.) SMS-Cs should not be open for SMS originating from prepaid customers different than their own.

To 1.) Operators should check whether their VLR carries out the barring correctly.Siemens: functionality can be activatedEricsson: functionality can be activatedNokia: ?Nortel: ?Alcatel: ?

To 2.) Operators with open SMS-C have been found e.g. in African countries. Those that were contacted “closed” their SMS-C to foreign customers.Operators should watch for networks operating open SMS-Cs and ask them to close them for customers different than their own.

MAP «Forward Short Message / SMS Submit

Forward Short Message / SMS Submit TCAP End «

SMSC B

MAP «Send Routing Info for Short Message

Forward Short Message / SMS Submit TCAP End «

MAP «Forward Short Message / SMS Deliver

Forward Short Message / SMS Deliver TCAP End «

HLR

HPLMN Mobile Network A