1. Destination Point Codes Assignement Telefónica Móviles S. A. U. October 2000 IFAST-14 Lima, Perú October 4-5, 2000

2. Telefónica Móviles S. A. U. There are two overlapping signalling networks: ITU Standard for voice traffic. ANSI Standard for Roaming Call delivery. Current situation This is an undesired situation, due to the interstandard IS –41, generally adopted in non-GSM networks, is an ANSI development

3. Telefónica Móviles S. A. U. Destination Point Codes (DPC’s) ANSI and ITU signalling Networks use different DPC’s numbering plan. While ITU DPC’s are assigned internationally and are widely used in voice traffic, ANSI DPC’s are supposed to be used internally in the United States. The fact is that ANSI DPC’s are the only way to establish roaming between IS-41 Signalling Networks. Non GSM Cellular Operators are compelled to use ANSI codes for roaming

4. Telefónica Móviles S. A. U. Destination Point Codes (DPC’s) IS-41 MAP ON ANSI TCAP ANSI SCCP/MTP IS-41 MAP ON ANSI TCAP ANSI SCCP/MTP ITU-T SCCP/MTP ITU-T SCCP/MTP application data exchange GATEWAY STP This configuration requires a mapping between ANSI and ITU DPC’s

5. Telefónica Móviles S. A. U. Destination Point Codes (DPC’s) IS-41 MAP ON ANSI TCAP ANSI SCCP/MTP IS-41 MAP ON ANSI TCAP ANSI SCCP/MTP ITU-T SCCP/MTP ITU-T SCCP/MTP GATEWAY STP ANSI COUNTRY NON ANSI COUNTRY ITU-T PC ANSI PC ITU-T PC

6. Telefónica Móviles S. A. U. Destination Point Codes (DPC’s) IS-41 MAP ON ANSI TCAP ANSI SCCP/MTP IS-41 MAP ON ANSI TCAP ANSI SCCP/MTP ITU-T SCCP/MTP ITU-T SCCP/MTP GATEWAY STP ANSI COUNTRY NON ANSI COUNTRY ANSI PC ANSI PC ITU-T PC

7. Telefónica Móviles S. A. U. ANSI DPC´s Assigment ANSI Comitee is responsible for this assigment (T1S1) Telcordia performs the assigment under a set of rules that do not consider the use of the DPC’s outside of USA. The assigment procedure can only be modified by ANSI Comitee.

8. Telefónica Móviles S. A. U. How DPC’s are being used Outside the U.S.? A U.S. Signalling Carrier, that has a DPC’s range assigned, uses part of its codes for addressing Southamerican, and Asian Operators. or The signalling Carrier performs a translation between ANSI DPC’s and International ITU codes. In both situations, Operators don’t have their own DPC’s, which are really assigned to the signalling Carriers

9. Telefónica Móviles S. A. U. What’s wrong with this situation? DPC’s must be set up in all networks which have roaming agreements. Up to now, roaming business was not very developed, and only a limited number of roamig agreements were established. An eventual change of DPC is an important task that must be performed in all networks at the same time. With the growth of roaming agreements, such a change will become a really difficult task. If operators don’t own their DPC’s, they are constrained to modify such key parameters if they want to change to a different signalling Carrier

10. Telefónica Móviles S. A. U. Conclusions A key parameter like DPC’s, cannot be out of the control of the Operators. The current situation is an obstacle for the opening of the market, making competition difficult which is a driving factor for the industry and operators. There should be a change in ANSI directives in order to provide South American Cellular Operators with DPC’s for roaming purposes. This will facilitate the growth of roaming agreements, with a direct effect on Carriers profits.