PABX/PBX, CDR/SMDR, VoIP and call accounting software

Call Accounting

At its very simplest a VoIP call accounting system stores information about telephone calls from phone systems as they happen for later analysis by a person or computer.

PABX/PBX

A typical business or office telephone system with more than one telephone extension or handset is known as a PBX (Private Branch Exchange) or PABX (Private Automated Branch Exchange). The PBX makes the connection between one or more telephone lines to the local telephone exchange and the telephone handsets in the office.

PBX extensions are not limited to handsets used by people but may include other extensions for use by auto attendants, hunt groups, voice mail, fax machines or other devices.

Graphical reports

Introduction to call accounting (1 minute)

World map Abandoned calls
Call traffic Call destination

CDR/SMDR

As telephone calls occur, information about the calls is sent to the PBXes SMDR (Station Management Detail Recording) or CDR (Call Detail Record) port on the PBX. A typical legacy SMDR connection might be a serial port operating at 9600 baud. Newer PBX SMDR ports might support a network connection.

Information about each call might be sent to the SMDR port as the call progresses or when the call has completed. SMDR information typically provides information such as when the call started, the duration of the call, the telephone extension that handled the call and the telephone line on which the call was made.

An example might look like:

Ext. Ln. Start            Duration Dialed  Type Account
100  01  2014-10-22 01:59 01:42    5551234 I    1466
101  01  2014-10-22 02:15 02:17    5551235 O
110  02  2014-10-22 02:23 42:04            I    1975
110  02  2014-10-22 01:41 02:42            I

Of course nearly every manufacturer does this a different way. Even different models of the same PBX may have different SMDR output.

Different column order, different date format and additional columns of information that may be available for the specific PBX. Some systems may not include the system date, others may omit the year, some may include information about abandoned calls others may include caller identification information.

VoIP PBXes and SMDR

Newer VoIP (Voice over Internet Protocol) PBXes have started making inroads into the PBX market. To the casual user they look and operate like legacy systems. Behind the scenes instead of telephone calls being sent over standard telephone lines the information is sent as internet traffic.

These systems can provide the same sort of SMDR information as 'normal' PBX systems though the manufactures of some VoIP systems provide more information about the digital traffic such as the number of bytes of information transmitted rather than information about the actual telephone call, for example, abandoned call information.

Some suppliers have forgotten that these things are PBXes.

Recording SMDR information

The simplest means of recording SMDR information, and perhaps the original reason SMDR ports were made available on PBXes, is to connect the serial SMDR port output to the input of a serial printer. As each call record is sent by the PBX to its SMDR port it is printed in chronological order.

Instead of connecting the SMDR port to a printer, connecting it to a computer and a terminal program the records can be displayed on a computer screen as they happen and saved to a file for later analysis.

Connecting a computer to a PBX

PBXes typically offer one of two means of connecting to a PC; via serial or via network cables.

A connection from a PBX to a PC via a serial cable usually requires that the PC is installed close to your PBX, this is due to the maximum length a serial cable can have and still operate. The maximum length of a serial cable at the most a few tens of meters.

A connection from a PBX to a PC via a network cable typically allows the PC to be located anywhere on your local area network.

Processing SMDR information

Once call accounting records are saved on a computer in a simple text format they can be opened in any standard program for basic call analysis. Simple analysis of such things as the extension with the most calls or the busiest time of the day can be performed with some manual call record filtering in programs such as Microsoft Excel.

Performing further analysis and correctly handling SMDR formats provided by different PBXes requires the use of a Call Accounting application.

Basic types of call accounting software

All call accounting software connects to your PBX and record call records as they are received from your PBX. If the call accounting software is not running the call records are usually lost. Some PBXes can store call accounting records for a while before losing the records.

The simplest call accounting programs run on your computer when you are logged in. If someone else logs into your computer the call accounting software does not receive any records.

Slightly more advanced call accounting software runs in the background and does not require someone to be logged into the computer for the call records to be received - if the computer is switched on the software is running.

The latest call accounting software runs as a very small program on an existing office computer and sends your encrypted call information via the internet to a hosted call accounting system. An alternative version of this is the call accounting application being installed as a black box that sends your call records to a hosted call accounting system. A 'black box' is just a small dedicated computer that just does this one job.

Why use call accounting software?

Having a call accounting package recording calls is all very well and good but the whole point of a call accounting system is to run reports, discover what type and how many of calls are being made with the goal of making money (or at least spending less), for example:

  1. Recharge call costs to different cost centers or customers
  2. Determine if you are paying for unused telephone lines
  3. Determine if you have too few lines to answer customer calls
  4. Determine if you are missing customer calls outside business hours
  5. Improve customer service answer times, response times and reduce transfers
  6. Discover telephone misuse by staff or third parties
  7. Detect toll fraud by third parties making unauthorized use of your PBX
  8. Protect your employees by reporting on malicious calls
  9. Understand your business productivity
  10. Understand your communications systems
  11. Support legal and regulatory requirements
  12. Discover employees making expensive long distance, mobile, international or premium service calls
  13. Discover employee loss of productivity by making many or long personal calls

Toll fraud

Toll fraud is the unauthorized use of use of your telephone system usually by people outside your business. The average toll fraud in Australia is currently thought to be $78,000 AUD.

Third-parties find a way into your PBX via a normal telephone line or via an internet connection. Once connected to your PBX unauthorized calls are then made to destinations such as international or premium rate numbers.

The first most businesses know about their system being fraudulently used in this fashion is when the monthly telephone bill arrives from their telephone provider.

A toll fraud detection system available as an option with advanced call accounting systems notifies you of fraudulent activity as it occurs.

Problems with classic call accounting systems

Having installed a call accounting system customers, after a while, discover problems:

System is slowing down

As calls are added to a call accounting system's database the database becomes larger and slower to respond and run reports. Even logging in to the system can become slower.

All call accounting software uses a database of some sort (even those systems that say 'no database' - where do you think the data is stored if not in a database? And, yes, a flat text file is a database.). To keep costs low, cheap or free database systems are used. Such databases provide little or no database maintenance tools and as a consequence database performance degrades over time.

The 'remedy' for a larger and slower database is to delete 'old' records. This is a temporary 'fix' and prevents you running reports on 'old' calls. How do you run a monthly or yearly comparison report when you've deleted older calls?

System is down

As many call accounting systems are installed in an out of the way place and only accessed once a month to do a monthly report or when there has been a complaint of misuse it is only when the system is needed is it discovered that it is not working.

The reason the system is not working may be simple to fix but by then a month's call records can be lost. System misuse cannot be traced, legal or regulatory requirements may not have been met and if you plan to recharge calls to third-parties you lose that income stream.

These are all real-world examples of call accounting systems failing and why telephone dealers typically hate call accounting software:

  1. The PBX is not sending SMDR information - a problem with the PBX or the SMDR port on the PBX may result in the PBX not sending any SMDR information. It may be possible to fix this problem by restarting the PBX otherwise a telephone technician may be required to fix the problem.
     
  2. The PC is not running - the PC may have stopped and not restarted due to any of the following; someone did 'the right thing' and turned off the computer before going home, no one is logged into the computer, the wrong person is logged into the computer, there is a floppy disk in the drive and the PC did not restart, the PC tried to boot from a CD, DVD or USB key, the hard disk in the computer has failed, the PC hard disk is full, a Windows update occurred and no one logged on, the machine is off after a power glitch.
     
  3. The PC is not receiving call records from the PBX - the cable from the PBX to the PC is unplugged; the PC was moved and the cable not reinstalled, someone needed the communications port for their application, the PBX was upgraded and the cable not reattached.
     
  4. The PC is missing! As stupid as it sounds that happens from reasons such as robbery to someone borrowing the 'unused' PC for another task.
     
  5. The call accounting software is missing - the PC on which the software was running has been changed, updated or replaced and no one knew the program was installed and being used.
     
  6. The date format is wrong - a call accounting system needs to know the date format used by the PBX SMDR, for example DMY (day month year) or MDY (month day year). If the PBX date format is changed and the call accounting configuration is not updated you might suddenly find your records are not being saved. If the date format is changed from DMY to MDY records for 06 April will be stored in the database for 04 June, records for 13 April won't store at all as there is no month 13.
     
    The date format is often changed by users thinking they are just changing the display on their own handset when in actual fact they're changing the date format of the PBX. Some PBXes when reset or after a power fault will default to MDY which may or may not be the same as the call accounting system configuration. Once the date format has been corrected you will have to tell your call accounting system to delete database records and reprocess calls with the new date format.
     
  7. The database has died - all call accounting systems require a database that can require maintenance to keep it running efficiently. Once it has died a technician has to be called to reinstall the application and install your daily backup.
     
  8. Having rebuilt your call accounting system you discover you have no backup.

Backup régime

An organized business takes backups of its systems and sends those backup tapes or disks to another location each day. A backup schedule requires at least 8 sets of backup media:

  1. 4 backups - Monday, Tuesday, Wednesday, Thursday
  2. 4 weekly backups - Friday 1, Friday 2, Friday 3, Friday 4

Backups are done each night and the backup tapes or disks are taken off-site (out of the office) each day. Off-site backups may be as simple as assigning a person at the office to change the tapes over each morning and take them home and remember to bring in the next tape the next day.

You do that don't you? You've also got to do the same for your call accounting system.

Logging into the system to run reports

Most call accounting systems allow one or more users to login to the system on the call accounting PC but not from their own PC. Due to the type of connection between the call accounting PC and the PBX the call accounting PC is often installed in an out of the way place that someone has to log into once a week or month to run reports.

Some systems get around this by running a terminal program on the call accounting machine so users can login from another machine. This sort of solves the problem but often only one person can login at a time and you can only do that from the office computer.

Larger call accounting systems require you to add extra software to other PCs to run reports on other PCs in your office. If you want to run reports from a PC outside your office you might be able to add an extra module to be able to run reports by connecting remotely to your office computer.

These so called remote access or web access modules attempt to add remote access to a legacy call accounting solution.

Multiple site (multiple office, multiple branch) call accounting

Usually call accounting systems log calls from a single PBX at a single office.

Some call accounting systems can be used as a multiple site call accounting system by installing a full system at each office and nominating one office as the head office. Each night all the branch offices call the head office and copy call information between systems.

Most call accounting systems are not really designed for multiple users or to process calls from multiple offices or multiple PBXes.

Hosted call accounting systems

A hosted system is a call accounting system that installs a very small program on a computer at your office or installs a black box and transfers the encrypted telephone calls to a dedicated call accounting data center.

Instead of the call accounting system requiring a dedicated PC, database, ongoing maintenance and backups the data is stored offsite and all the modules likely to fail are at the remote data center.

Call Accounting

  1. Daily off-site backups are performed by data center staff
  2. Database maintenance and performance tuning performed by data center staff
  3. System upgrades are automatically performed
  4. You're always using the latest version of software, the same version as nation-wide companies
  5. Multiple user accounts can be created
  6. Multiple sites are supported with no special changes to your system
  7. Access can be restricted to a department or region
  8. Access can be restricted to reporting only preventing administration access
  9. You can log in from any computer, anywhere without installing special software
  10. Designed from day zero to support multiple sites, multiple users, multiple user types
  11. Designed from day zero to be a remotely accessed hosted call accounting solution
  12. Custom database columns
  13. Custom report layouts
  14. Custom emailed report schedule
  15. If your PBX or PC has problems you're automatically alerted by email or SMS
  16. Supports legacy key systems and VoIP PBXes
  17. Call information sent encrypted to data center
  18. All access to system configuration and reports via secure SSL web browser such as IE, Firefox
  19. Access from your Apple, Linux, Windows PC or mobile device
  20. Toll fraud detection and alerting included in the standard version
 
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