the scene of the incident (e.g. relatives, or alarm monitoring corporations). When calling from a telephone not at a fixed location (mobile), it is necessary for the caller to specify the location. Victoria In the state of Victoria, emergency service dispatch and call taking for Victoria Police, Ambulance Victoria, the Country Fire Authority, and the Fire Rescue Victoria, is handled by the Emergency Services Telecommunications Authority (ESTA). ESTA operates three State Emergency Communications Centres, located in Williams Landing, East Burwood, and Ballarat. When a person calls 000 for emergency response within Victoria, the call will be answered by Telstra who determine the service required. The call is then directed to the relevant ESTA facility where it will be answered by the next available trained call taker, who will collect information from the caller, and enter this into the Computer Aided Dispatch (CAD) system. Using this information, a dispatcher will identify and dispatch the appropriate emergency services or resources. Emergency crews are often already being notified by the relevant services' dispatchers while the call taker is still obtaining further information or giving advice, such as guiding the caller through cardiopulmonary resuscitation (CPR), obtaining details of a possible offender, or receiving further details about the exact location or situation - an initial response may be made to details as vague as a town or suburb, while the call taker continues to get more specific location information. ESTA is also responsible for Victorian State Emergency Service (SES) call-taking and dispatch, although this service cannot be contacted by dialling 000, as SES calls are not considered to be life-threatening. The number for SES calls is 132 500, but police or another service dialled inappropriately will notify SES. Many ESTA practices and protocols are standardised across all emergency services agencies, and all agencies use the same computer network. The result is complete and instantaneous information sharing between emergency services. Issues 2003 overload in Melbourne On 3 December 2003, floods and storms in Melbourne, Victoria, caused "an extremely high number of calls to the 000 emergency call service", which prevented some calls from being answered immediately. This delay was compounded by a software upgrade on the emergency call handling system used by the Victorian emergency service organisations (ESOs), meaning that Telstra (the national 000 call operator) encountered severe delays in handing over emergency calls to the relevant ESO. This caused some users interviewed by authorities to