Billing System Costs

Billing system costs include the initial hardware, software costs of the system along with the operational costs such as invoice processing, bill printing and mailing, intermediary clearing house settlement companies, customer care (call centers), and collection services.

Hardware and Software

The hardware usually includes high performance computers that operate proprietary software. Due to the complexity of hardware and software billing systems, continuous training operations support may be required to ensure quality services to the customers and to provide revenue assurance.

Invoice Processing (Batching)

Periodically, billing records are gathered for invoicing. If a company has many customers, they may be divided into cycles (or “billing cycles.”) The billing cycles are different for groups of customers. This allows the billing system to only batch a portion of the billing records each time. These billing records must be forwarded for delivery (to a bill printer or for electronic distribution).

Bill Printing and Mailing

In most cases, invoice records are sent to a bill printer or they may be sent by email or printed by the customer when the payment is made online. When bills are sent to the printer and mailing house, this usually costs between $1-$3 per bill. Sending bills by email helps to reduce the cost of providing the customers with bills and receipts.

Call Center

A call center is a place where calls are answered and originated, typically between a company and a customer. Call centers assist customers with requests for new service activation and help with product features and services. A call center usually has many stations for call center agents that communicate with customers. When call agents assist customers, they are typically called customer service representatives (CSRs).

Call centers use telephone systems that usually include sophisticated automatic call distribution (ACD) systems and computer telephony integration (CTI) systems. ACD systems route the incoming calls to the correct (qualified) customer service representative (CSR). CTI systems link the telephone calls to the accounting databases to allow the CSR to see the account history (usually producing a “screen-pop” of information).

Call center telephone systems can cost over $3,000 per CSR station. The average telecommunications service provider has 1-2 CSRs for every 10,000 customers. This results in an average customer care call costing $7-$10 per call.

Figure 1 shows a typical call center. This diagram shows that calls may be received or originated from the call center. The customer traditionally communicates with the call center by telephone. When a call is received by a call center, the user is typically provides with a list of options by an automated interactive voice response (IVR) unit. As the user selects from the list of options, an ACD system routes the call to a CSR station that is qualified to assist the customer (e.g. sales agent or technician). When the CSR agent answers the call, some of the customer’s account information may become available on the CSR’s computer screen (“screen pop”). The CSR will communicate with the customers and should make notes in the customer’s account regarding the activity that progressed.

Figure 1: Call Center


Collections are activities that a service provider performs to receive money from their customers. Ideally, all customers will receive their bills and pay promptly. Unfortunately, not all customers pay their bills and service providers must have a progressive collection process in the event a customer does not pay their bill.

When customers are first added to a system, they are rated on the probability that they will pay their bills. This is accomplished by using information on their application and reviewing the credit history as provided by an independent credit reporting agency.

The collection process for delinquent customers usually starts by sending a reminder messages to the customer be mail or recorded audio message. If initial attempts to collect are unsuccessful, more aggressive collection activities will progress that include restricted calling, service disconnection and sending or selling the uncollected invoice to a collection service.

A restricted calling class that forces a telephone (usually a wireless telephone) to be connected to an operator regardless of the digits actually dialed. Hotline is typically used when a telephone is first sold or activated to allow activation after the customer has provided the information to register for service or when the customer has not paid their bill.

If all attempts to collect from a customer have failed, a service provider may write off the uncollected revenue as bad debt, retain a collection agency or sell the uncollected invoice(s) to a collection service. If the account is written off as bad debt, the customer’s information is usually placed in a negative file to avoid reactivation and their poor payment history is reported to a credit reporting agency. Various collection companies (collection agencies) offer collection services that work on a percentage of collected revenue. Some collection companies will pay for uncollected invoices. When uncollected invoices are sold to collection services, the service provider is usually prohibited from working with the customer in the future regarding payment on the account.

Customer Relationship Management (CRM)

Customer relationship management (CRM), also called customer care, is the process of communicating with the customer regarding their establishing accounts, service feature activation, handling customer inquiries adjusting accounts for disputes (account management), technical support, selling additional products and services to the customer (post sales support), and collection services.

Account Activation

Account activation is the acquiring and entering information that is required for the system to provide services to a customer. The account activation may involve many steps prior to the entry of information to the system. Account activation steps may require the customer to complete an application for service, credit check, and copying of documents that validate the identity of a new customer (to prevent fraud). Account activation also involves assigning the customer to specific rate plans for service charges.

Account activation involves informing network equipment of customer account information and what services they are authorized to use. This is called provisioning of the network.

Account Management

Account management involves communication with the customer for sales related and collections activities. Usually, all communication with the customer is recorded in various formats such as call records and voice recording.

Account management also involves creating records to track technical problems the customer may be experiencing with their service. These records of trouble (often called “trouble tickets” are routed to technical support. These trouble tickets remain open so managers can review progress until the problem is solved.

Account managers may also receive inquiries or billing complaints that require message investigation. Message investigation reviews billing records to resolve customer disputes. In some cases, account managers may be used to assist in the collection of outstanding invoices.

Invoices & Management Reporting | Major Billing Functions


Invoices contain the details of how much the customer should pay to the carrier, when the amount is due, and other information regarding the bill. Invoices usually provide a customer with detailed information regarding the source of the charge (date and location), reasons for the charge (service provided), and the amount of the charge. Figure 1 shows a sample invoice.

Figure 1: Sample Invoice

Management Reporting

Management reports provide information to finance, sales, and operations on the performance of the system. Reports can identify problems such as, silent churn, potential new services, and network congestion. Churn is the process of customers disconnecting from one telecommunications service provider. Churn can be a natural process of customer geographic relocation or to may be the result of customers selecting a new service provider in their local area. Silent churn is the process of customers disconnecting from one telecommunications service provider due to a competitor’s influence. Silent churn is usually the result of inadequate customer service or lack of competitive rate plans. Customers that are transitioning to competitor’s services will show rapid declines in usage of service.

Management reporting can also be used to discover new services. By reviewing call patterns, churn and silent churn patterns, and customer feedback, managers can determine which new services may be good candidates for their system. CDRs and network activity can also indicate areas of network congestion and corrective measures (rerouting or adding resources) can be accomplished to overcome the challenge.


Invoicing is the process of gathering of items to be billed (rated CDRs) that have occurred over an invoice period, adding additional charges and credits that are not related to specific calls, and preparing the information (formatting) so it may be presented to the customer in a clear way. Invoices may be delivered by mail or in other formats such as by email (e-commerce).

Processing Payments

Processing payments involves collecting assets to settle the customer’s invoices. The typical form of payments that are received from customers include checks, cash, wire transfer, credits, and credit cards. However, other payments or credits may be applied to the customers account.

Recording the payment to the customer’s account is called posting. Posting usually involves using a payment coupon that has an account number on it and posting the received amount of money to the account. In the ideal situation, the customer has provided the payment coupon with the correct amount. In other cases, the customer may have not included the payment coupon or may pay a different amount than indicated. In this case, posting of payments may result in errors such as posting to the wrong account or applying payment new invoices instead of old invoices.

Posting to the Financial System

The billing system records and groups financial details (receivables and payables) for the company. Periodically, summary information is transferred into the general journal of the company’s accounting system. This summary posting groups different types of billing charges into summary totals to be posted to different financial accounts. These types of accounts include receivables or expenses and each account is assigned a unique number (in the financial chart of accounts). For example, payments received by credit card are usually categorized differently than payments received by cash and these totals will be recorded in accounts with different account numbers.

Back End: Cycle Billing & Clearinghouse | Major Billing Functions

Back End: Cycle Billing

The back end of the billing system uses data from the updated bill pool and adds non-call related billing charges and financial adjustments. The billing system then adds fixed recurring charges (such as monthly service fees and taxes), applies payments that have been received, produces invoices, and maintains a history database for legal purposes (government regulations) and customer care systems.

Figure 1 shows the basic call-rating process. This diagram shows that a call detail record evolves as it passes through the rating process. In the first step, a rate band is determined. Then, the identification information on the CDR is used to identify a specific customer’s account (guide the record). The customer’s rate plan is discovered and the unit (usage) and fixed (per event) charging rates are gathered and calculated. The new information (rate band, call charge amount) is added to the call detail record and it is moved to the bill pool, as it is ready to be billed.

Figure 1: Back End: Cycle Billing.
Source: The Billing College


A clearinghouse is a company or association that transfers billing records and/or performs financial clearing functions between carriers that allow their customers to use each other’s networks. The clearinghouse receives, validates and accounts for telephone bills for several telephone service providers. Clearinghouses are particularly important for international billing because they convert different data record formats that may be used by some service providers and convert for the currency exchange rate.

Clearinghouses provide a variety of services including processing proprietary records (e.g. switch records) into formats understandable by the member carriers’ billing systems, validate charges from carriers with intersystem agreements, and extract unauthorized or un-billable billing records. Clearinghouses transfer messages in a standard format such as exchange message record (EMR), cellular inter-carrier billing exchange roamer (CIBER), or transferred account process (TAP) format. The EMR format is often used for billing records in traditional wired telecom networks and the CIBER and TAP formats are used for wireless networks. The records may be exchanged by magnetic tape or by other medium such as electronic transfer or CD ROM.

Clearinghouses receive billing records from companies (outcollects - sometimes called in-roamers) and submit billing records to companies (incollects - sometimes called out-roamers). Outcollects are billing records that are sent to other systems to collect for services provided to visiting customers. Incollects are billing records that are received from other systems for services provided to their customers that have used the services of other networks.

Inter-carrier billing systems must be capable of handling billing system errors. There are many events per call and the possibility exists for duplicate records or missing details in the billing records. Charges or records may be received for customers that do not exist in the local system or the inter-services (or roaming) agreement between companies may not be valid. Charges or records may be received from other companies (incollects) that have crammed or slammed bills. Cramming is the erroneous or fraudulent addition of charges for services that were not agreed to by the end customer. Slamming is the unauthorized transfer of customer’s preferred service provider to a different service provider. When errors or omissions are detected, individual CDRs or entire batches of billing records may be flagged for return to the sender and they may be tagged for further investigation.

Front-End: Call Processing | Major Billing Functions

Major Billing Functions

Billing systems can be divided into two major functions: the front-end and back-end processes. The front-end process accepts messages from a service providers’ own switches or from other telephone or billing company’s systems (called incollects), checks the validity of billing records, matches billing records to customers in a database, and provides billing details to other systems (called outcollects). The front-end process also guides billing records to specific customer accounts. Guiding uses the call detail record identification information such as the calling telephone number to match the billing record to a specific customer account.

The back-end of the billing system aggregates billing records for a specific period (billing cycle), calculates recurring charges (e.g. monthly charges) and total usage charges (minutes or quantity of usage), and produces invoices.

Front-End: Call Processing

Call processing is the steps that are typically associated with the routing and control of the call. When used as part of a billing system, call processing receives call details from various sources (event records), reformats and edits these into call detail records (CDRs), calculates call charges for each CDR, assigns a customer account to the CDR (guiding), and gets the CDR ready for billing.

In a traditional voice telephony environment, Call Processing involves the processing of call detail records in a batch mode (or at best in near real-time). There may be several call detail events and records for each call. For example, a call may be completed from a local switch, translated by an 800 number service, and routed through a long distance switch. All the call detail events are relative to billing the call. Billing and call processing can require a substantial amount of computer processing time because there may be many events for each call.

Each CDR is rated for billing to assign a charge (cost) for each call. This rating process may involve the assignment of a rating band or category first. The actual billing charges may be added or updated after the banding or rate category assignment of the call detail record. After a CDR has been rated and the actual charge for the call is calculated, the call detail record is moved into a “pool” of billing records that are ready to be invoiced (called a bill pool). A bill pool is a group of call records that have been updated by the call processing stage in a billing system to include charging rate information. The bill pool usually contains records that are ready for the final stage of bill processing.

Figure 1 shows the basic functions of the call-processing section. This diagram shows how different event sources are received by the call-processing system. These event sources may be from the network elements or from other companies that have provided services to your customers. These records are reformatted to a common CDR format and duplicate CDRs are eliminated. Identification information in each call detail record is used to guide (match) the record to an account in the customer database. The customer’s information determines the rate plan to use in charge calculation. The rating database uses rate tables, the customers selected rate plan, and possibly other information (e.g. distance, time of day) to calculate the actual charge for each call. All of the information is added to the CDR and it is either placed in the bill pool (ready for billing), or it is sent to another company to be billed if the customer identification is not part of this network’s customer database. If there are any problems with call processing, the call detail records are sent to message investigation for further analysis.

Figure 1: Call Processing.
Source:The Billing College

Rating is the process of guiding call detail records to the correct customer records (locating the customer for the event), identifying the rate plan (from rate tables), and adding this rate information to the call detail record.

Billing systems contain many databases of information. Some of the key databases hold customer information, call detail records, rate tables, and billing records that are ready to be invoiced. A customer database holds unique identification information about the customer. This includes a customer account identification number, telephone number (may be the same as the account number), authorized feature list, rate plan identifier (which rate plan the customer subscribes to), service activation dates, and other information specific to a customer or account. A rating database holds the rate plan identifier codes and charges associated with each rate plan.

It may be necessary to divide the CDR into several components parts. For example, a call from a mobile telephone may be divided into airtime, landline usage, and long distance usage.

CDRs are commonly processed using a single call rating software module. This module uses rate plan identification information found on the CDR (determined after the guiding process) to match to rate tables that allows a per unit increment rate. Rate increments can vary based on the time of day (TOD), day of week (DOW), holidays, and other factors. After the call rate has been determined, the billing system places an initial value on the call. It may be necessary to re-rate the call based on information received after initial rating was calculated. Examples of this include; usage discounts (free minutes), toll free calls (calling party pays), and calls billed using an old rate table after a customer has selected a new rate plan.

Event Sources and Tracking ; Mediation Devices ; CDR | Billing Process

Billing Process

Billing systems are composed of computers and software programs that track usage within a network (events) and converts them into a single detailed billing record. Events within a network can come from many sources; a switch, data router, application service provider and they must be converted into a standard format.

Billing and customer care systems may be developed and managed by internal staff or contracted to other companies (outsourced).

Companies that provide complete managed billing and/or customer care services (called turnkey) to other companies are called service bureaus.

Event Sources and Tracking

Billing system events are measures of network usage. Events can be stored in the network device (Data Collector) for transfer at predetermined time intervals, when a specific value has been reached (event trigger) or when the billing system requests the information (called polling).

Some common event sources include central office switches, routers, and application servers. Central office switches are devices that route Source: The Billing Collegecalls from one subscriber to another. They track the time one port is connected to another port. Routers are intelligent switches that forward packets toward their destination based on their routing address (and possibly type of content). Routers can track the amount of data that is routed between two ports over a period of time. Application servers are computers that process information at the request of a customer (called a client), and can track the beginning (launching) and termination of an application.

Mediation Devices

A mediation device receives, processes, and reformats event information in a telecommunications network to a suitable format for one or more billing and customer care systems. This processed information is either continuously or periodically sent to the billing system. Mediation devices are commonly used for billing and customer care systems as these devices can take non-standard proprietary information from switches and other network equipment and reformat them into messages billing systems can understand.

Switches usually report their usage information (e.g., switch connection time) in binary coded decimal (BCD) format and these record formats are often proprietary to the manufacturer of the switch. Each record may be variable length and several events (e.g. switch points) may be recorded in the same system for a single call. There are at least 60 switch manufacturers and each has several models of switches that may result in different billing record formats.

There are other network parts or devices that may be involved with connecting a call or providing value added services (VAS). These devices also can produce cal detail records and these records are in a different format.

Figure 1 shows a mediation system that takes call detail records from several different switches and reformats them into standard call detail records that are sent to the billing system. This diagram shows the mediation device is capable of receiving and decoding proprietary data formats from three different switch manufacturers. The mediation device converts these formats into a standard call detail record (CDR) format that can be used by the billing system.

Figure 1: Mediation System

Call Detail Records (CDRs)

Billing information regarding specific calls are contained in call detail records. CDRs hold the origination and destination address of a call (who), time of day the call was connected and duration of the call (when), the call type and its details (what), the connection location(s) of the call (where), and the cause of event recording (why). When the call detail record holds information other than telephone billing information (e.g., the name of a movie watched), it may be called an event detail record (xDR). xDRs hold billing record information about services that are non-traditional telecommunication services such as an information services that are provided through the Internet.

Figure 2 shows the basic structure of a call detail record. This diagram shows that a call detail record contains a call detail record identification number (unique identifier), who originated the call, the called number, the time the call started and completed. This diagram shows an additional charge for operator assistance and that a call detail record can dynamically grow as multiple events add information to the call event.

Figure 2: Call Detail Record (CDR)
Source: The Billing College

Multilingual Support & Multiple Currencies & Inter-carrier Settlements | Introduction to Billing

Multilingual Support

Multilingual support involves providing invoices and customer care services in multiple languages. There is a growing trend to aggressively seek multinational customers and it is becoming crucial for the billing system to invoice customers in their chosen languages. Multilingual support may also be required by government regulations. Customer service representatives (CSRs) with multiple language skills should be available to communicate with customers. Some of the key challenges associated with supporting multiple languages include single versus double-byte character set support, invoice design, equipment compatibility (printers, monitors, keyboards, etc.), and software drivers.

Multiple Currencies

Multiple currencies used in different countries can complicate the billing system as the billing and customer care system must be capable of recording and processing in units of multiple currencies. Multinational companies will most likely process in multiple currencies. Some of the complications of multiple currencies include: rounding rules, significant digits, timing of rate conversion, payments made erroneously in a different currency, and rapid changes in exchange rates.

Inter-carrier Settlements

Inter-carrier settlements are the exchange of value between carriers that provide services to each other. Because hundreds of carriers may be providing services with each other, inter-carrier settlements are often provided on a wholesale basis between network operators based on prearranged agreements between the carriers. In the United States, inter-carrier settlements are enabled through the use of carrier access billing system (CABS) or independent clearing houses.

Inter-carrier settlements are becoming more complicated with deregulation. To encourage fair competition, some governments are requiring existing (incumbent) telecommunication companies to unbundle network elements (UNE). Unbundling is the process of separating portions of a telecommunication network that are owned or operated by a service provider. It is a common term used to describe the separation of standard telephone equipment and services to allow competing telephone service providers to gain fair access to parts of incumbent telephone company systems. An example of an unbundled service is for the incumbent phone company to lease access to the copper wire line that connects an end user to the local telephone company. The competing company may install high-speed data modems (such as ADSL) on the copper line to enhancing the value of the telecommunications service.

Real Time Billing | Introduction to Billing

Real Time Billing

Real time billing involves the authorizing, gathering, rating, and posting of account information either at the time of service request or within a short time after the call has been initiated (this actually may be several minutes). Real time billing is primarily used for prepaid services such as calling cards or prepaid wireless.

Real time billing involves authenticating, authorization, and accounting. Many real-time billing systems use remote access dial in user server (RADIUS) to limit the access to the system to registered and authorized customers. RADIUS is network protocol that operates on a network server (software program and database) that receives identification information from a potential user of a network service, authenticates the identity of the user, validates the authorization to use the requested service, and creates event information for accounting purposes.

Real time billing may also provide for better customer care and provide advice of charge (AOC) information. AOC provides the ability of a telecommunications system to advise of the actual costs of telephone calls either prior or after the calls are made. For some systems, (such as a mobile phone system) the AOC feature is delivered by short message service.

Figure 1 shows a real time prepaid billing system. This diagram shows that the customer initiates a call to a prepaid switching gateway. The gateway gathers the account information by either prompting the user to enter information or by gathering information from the incoming call (e.g. prepaid wireless telephone number). The gateway sends the account information (dialed digits and account number) to the real time rating system. The real time rating system identifies the correct rate table (e.g. peak time or off peak time) and inquires the account determine the balance of the account. Using the rate information and balance available, the real time rating system determines the maximum available time for the call duration. This information is sent back to the gateway and the gateway completes (connects) the call. During the call progress, the gateway maintains a timer so the caller cannot exceed the maximum amount of time. After the call is complete (either caller hangs up), the gateway sends a message to the real time rating system that contains the actual amount of time that is used. The real time rating system uses the time and rate information to calculate the actual charge for the call. The system then updates the account balance (decreases by the charge for the call).

Figure 1: Real Time Billing

Types of Services & Standard Billing Process | Introduction to Billing

The control of a billing system is usually under the finance department. Billing systems are often viewed as accounts receivable as the billing system assists in the collection (receipt) of money from customers. Billing systems are also is part of accounts payable (for inter-carrier settlements) as customers often use services from other companies such as long distance and call completion through other networks. The network operator is usually financially responsible for services provided to their customers by other networks regardless if the customer pays for the service or not.

Types of Services

There types of services that a customer may use in a network include system access (basic information transfer), information processing (such as email), and content delivery (current traffic information for example). When the communication service involves system access through different networks, the call is normally routed through a toll center and a toll charge may apply. A toll is any message telecommunications charge for services provided beyond a local calling area.

Examples of system access services include plain old telephone service (POTS), integrated services digital network (ISDN), digital subscriber line (DSL), and other data connectivity services that transfer information between points. Information processing services include phone card (Telecard), voice mail, fax store and forward, and other services that involve the processing of information that is passed between two or more points. Content delivery involves linking customers to sources of information content and transferring the content to the end customer. Examples of content delivery include weather advisory services, stock quotes, and the delivery of other sources of information that the customer requests.

Standard Billing Process

The typical billing process involves collecting usage information from network equipment (such as switches), formatting the usage information into records that a billing system can understand, transferring these records to the billing system, assigning charge fees to each record, receiving and recording payments from the customers, and creating invoices.

Figure 1 shows a standard billing process. In this diagram, the customer calls customer care or works with an activation agent to establish a new wireless account. The agent (customer care) enters the customer’s service preferences into the system, checks for credit worthiness, and provides the customer with a phone number so that the customer may make and receive calls through the telephone network. As the customer makes calls, the connections made by the network (such as switches) create records of their activities. These records include the identification of the customer and other relevant information that are passed onto the billing system. The billing system also receives records from other carriers (such as a long distance service provider, or a roaming partner). The billing system now guides and updates these call detail records (CDRs) to their correct customer and rating information. As information about the customer is discovered (e.g. rate plan), the updated billing records are placed in a billing pool so that they may be combined into a single invoice that is sent to the customer. The customer then sends his payment to the telecom service provider. Payments are recorded in the billing system. History files are then updated for the use of customer service representatives (CSRs) and auditing managers.

Figure 1: Standard Billing Process. Source: The Billing College

Overview | Billing and Customer Care

Billing and customer care systems convert the bits and bytes of digital information within a network into the money that will be received by the service provider. To accomplish this, these systems provide account activation and tracking, service feature selection, selection of billing rates for specific calls, invoice creation, payment entry and management of communication with the customer.

Billing and customer care systems are the link between end users and the telecommunications network equipment. Telecommunications service providers manage networks, setup the networks to allow customers to transfer information (provisioning), and bill end users for their use of the system. Customers who need telecommunication services select carriers by evaluating service and equipment costs, reviewing the reliability of the network, and comparing how specific services (features) match their communication needs. Because most network operations have access to systems with the same technology, The billing and customer care systems are the key methods used to differentiate one service provider from another because most network operations have access to systems with the same technology.

There are many different types of services to be supplied and billed. These include traditional voice, short messaging, fax, data communications, and information services. Billing systems process the usage of network equipment that is used during the call (events) into a single Call Detail Record (CDR). The billing process involves receiving billing records from various networks, determining the billing rates associated with the billing records, calculating the cost for each billing record, aggregating these records periodically to produce invoices, sending invoices to the customer, and recording payments received from the customer.

Customer care systems, sometimes known as provisioning systems, provide customer service representatives (CSRs) with tools to assist and standardizes communication with the customer.

Billing system costs can be a substantial percentage of revenues collected. In addition to the initial acquisition cost of computers and software, operational costs are very high. Of the service provider’s staff, 20%-30% directly or indirectly provide billing and customer care support.

There are many billing standards that have been developed for telecommunications networks. Because the services offered by different types of network operators (e.g. cable television compared to local telephone companies) are beginning to overlap, billing standards are also converging.

Future trends and challenges for billing systems include new types of services to bill for, telephone number portability that complicates account identification numbers, and increased customer self care to reduce the burden (and cost) of billing systems.

Figure 1 shows an overview of a billing and customer care system. This diagram shows the key steps for billing systems. First, the network records events that contain usage information (for example, connection time) that is related to a specific call. Next, these events are combined and reformatted into a single call detail record (CDR). Because these events only contain network usage information, the identity of the user must be matched (guided) to the call detail record and the charging rate for the call must be determined. After the total charge for the call is calculated using the charging rate, the billing record is updated and is sent to a bill pool (list of ready-to-bill call records). Periodically, a bill is produced for the customer and as payments are received, they are recorded (posted) to the customer’s account.

Figure 1: Billing and Customer Care System.
Source: The Billing College

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