| VoIP and Geographic Location | | | | the CLI is concerned, the call is being made from the |
| The emergency services have come to rely on | | | | local switch in Edinburgh to the end-point, while the |
| certain features of the traditional telephone system to | | | | actual origin of the call is completely unknown. If the |
| enable them to do their jobs and to safeguard against | | | | ITSP customer were simply calling the local fire |
| misuse of the general public's privilege to call them | | | | brigade, the call would travel over the Internet to the |
| night or day. The key feature is the Caller Line | | | | ITSP who would then make the connection to the |
| Indication (CLI). This is a number unique to every | | | | emergency service from its own public network |
| telephone line attached to the public network and it is | | | | gateway. From a CLI perspective, the call to the |
| possible to trace the location of the telephone that | | | | emergency service would appear to come from the |
| made a call from the CLI. | | | | ITSP. |
| The CLI enables fire and ambulance services to locate | | | | VoIP and Power |
| where they are needed should the caller be unable to | | | | The traditional telephone network is self powered. If |
| tell them; they may be too young, old or infirm to do so. | | | | the general power supply goes down as it often does |
| The CLI enables the police and security services to | | | | in an emergency, the phone system will still work as |
| locate the source of criminal use by using the | | | | the phone companies have extensive uninterruptible |
| telephone network. Meanwhile location can be | | | | power supply (UPS) contingencies. VoIP systems |
| ascertained on the mobile network through tracing the | | | | require an external power source, and if the power |
| call to the base station to which the mobile phone is | | | | fails, unless the user has implemented their own UPS |
| connected. | | | | solution, the phones will not work. |
| On the other hand, an IP telephone is recognised not | | | | The Immediate Solution |
| by a CLI, but by its IP address which as no geographic | | | | To ensure emergency cover, VoIP system users, at |
| meaning. Indeed one of the advantages of VoIP is that | | | | this time, need the contingency of at least one |
| wherever in the world an IP phone connects to the | | | | traditional telephone line. VegaStream gateways' |
| Internet, the Internet will find it to deliver the call. Given | | | | feature a pass-through facility which can be |
| this, the emergency services will have no idea from | | | | programmed to automatically make and receive calls |
| where the call originates. | | | | over this line in the event of power failure. The |
| Currently, most VoIP solutions carry calls between | | | | gateway can also be programmed to automatically |
| company locations and calls to the public telephone | | | | route 999 emergency calls over this line to ensure the |
| network are made via a gateway, such as those | | | | emergency services receive the vital CLI information. |
| provided by VegaStream. In this scenario, the problem | | | | The Long Term Solution |
| for identifying the location of a phone is similar to that | | | | There are a number of national, supranational and |
| faced when a company uses a traditional PBX | | | | industry wide initiatives to establish and implement |
| solution, although most responsible companies have | | | | standards for geographic recognition of IP telephony |
| implemented an appropriate solution by mapping their | | | | equipment to meet the requirements of the |
| IP phone addresses to a traditional list of extensions. | | | | emergency services. The large national phone |
| VoIP systems can connect to the public telephone | | | | companies that are in the process of converting their |
| network via Internet Telephone Service Providers | | | | traditional phone networks to VoIP are actively |
| (ITSP). ITSPs offer significant reduction in call charges | | | | involved as they too have a vested interest. |
| by carrying what are the expensive elements of the | | | | Furthermore, in the enterprise space, responsible |
| phone call over the Internet. | | | | systems integrators will ensure that CLI information is |
| For example, an ITSP customer's call from London to | | | | available both to assist the emergency services and to |
| Edinburgh is carried from London to a local switch in | | | | meet basic requirements of good citizenship and good |
| Edinburgh via the Internet. Just the final leg of the call is | | | | business. |
| made over the traditional telephone network. As far as | | | | |