The CoBilAS architecture with its unique Clearing System Engine is the perfect basis for practically any system needing to reliably account for event-based business transactions, i.e. in the telecommunications industry. The following sections helps you to understand the unique CoBilAS architecture.

Press PLAY to start the animation of the CoBilAS “coffee mill”.

The Origin

Observing the billing systems currently in use we found it quite astonishing that none of these systems seem to truly address all the operator’s needs.

Currently, companies spend a lot of money on multiple billing systems - different systems for pre- and postpaid customers, for different services, for roaming andinterconnect. The customization of all those billing systems also costs a large amount of money for consultants, hardware, maintenance fees, change requests and middleware. All those issues eat up a good portion of the operator’s revenue.

Despite the huge amount of money invested in these systems they are still prone to error due to their architecture of billing with multiple independent stages and their inability to exactly document any calculations made.

With this in mind, the CoBilAS team had the vision and staying power to build a new system to completely overcome these (as well as other) limitations by implementing a system which is able to account for any number of fees for any number of participants, based on an incoming event representing a business transaction.

Unique Reliability

The CoBilAS core is built around a unique Clearing System Engine which is based on the simple fact that an incoming event (i.e. a Call Detail Record) fully describes a business transaction with a certain number of participants, i.e. subscriber, service provider and operator. The only additional data necessary are the contracts of that business transaction’s participants, their accounts and account balances.

CoBilAS allows the complete specification of all the necessary contract rules so that the Clearing System Engine is then able to easily calculate all the bookings needed to represent that business transaction on the appropriate accounts of all the participants in a highspeed, real-time mapping process.

All such bookings are handled in compliance with the Generally Accepted Accounting Practice, so that there is always an exact cross-check between all the affected accounts. This compliance should be a basic requirement to all billing systems but - possibly due to their more technical origin - is neglected by all the systems we observed. This principle is one of the foundations of CoBilAS’ unique reliability.

Clearing Systems

As it is the core of CoBilAS, the Clearing System Engine naturally has to fulfill all the requirements the CoBilAS spec book itemizes. In addition to the general requirements mentioned, this includes - but is not limited to - requirements like:

  • cross-technology convergence to seamlessly handle packet- and circuit-switched events within virtually any environment (IMS, GSM, UMTS, VoIP, Interconnect, etc.),

  • unlimited subscriber hierarchies with accounts attached anywhere within the hierarchy, flexible accounts handling values in any unit (i.e. money in different currencies, miles & more, minutes) either pre- or postpaid,

  • flexible zone based pricing breaking down the barrier between i.e. zone, prefix and friends & family,

  • bonus management to include any kind of promotions within the real-time processing.

100% Object-Oriented

All the requirements and design decisions mentioned above - plus the strict requirement that the CoBilAS core is kept protected as well as consistent, yet easily extensible - make the use of 100% object-oriented software development methods inevitable.

This extends to the database, as a relational database prevents an easily and consistently extensible core release. Adding a user-specific column within a relational database always means that this data has to be taken into account in the original handling of that database table. Manipulating this data later would lead to very serious performance degradation, as well as problems with transactional consistency.

Only object-oriented databases integrate with the application in a way which allows additions without touching the core. These databases also make it unnecessary to have additional object relational mapping which degrades performance and is open to more errors.


Versant’s object-oriented FastObjects database not only allows the efficient addition of customer-specific features, but it also provides additional features making it the ideal choice for CoBilAS:

  • High availability by allowing i.e. a cluster switchover within a second while the clients could still work using data from their caches.

  • Load distribution the load of large search and retrieval transactions can be easily switched to asynchronous replications of the main database where just the transactions of the last milliseconds are missing.

  • Zero downtime as the database never has to stop within a database cluster. Neither backups, nor changes in the database schema imply a shutdown of the database.

  • Security The database itself as well as the communication between client and server could be encrypted to add an additional level of security for customers i.e. preferring a distributed environment.

  • RDBMS Usage is a feature interesting for customers highly dependent on relational databases like Oracle, DB2 or Microsoft SQL Server. FastObjects provides an RDBMS connector which stores all the object data within a relational database. In this case FastObjects simply becomes an object-oriented library interfacing with the RDBMS. As this is configured invisibly for the application within the database layer there is no need for any changes in CoBilAS’ source code to profit from this feature. Additionally, FastObjects allows the storage of only certain portions of the data within a relational database. In this way CoBilAS is able to offer the operator the handling of data like the subscriber’s name and address with conventional tools, while still profiting from all the sophisticated features CoBilAS provides.

Open Interfaces

With the variety of, for instance, network switches currently in the market it is vital to support flexible and customizable interfaces.

The CoBilAS mediation and provisioning supports ASN.1 and XML based interfaces within the standard product which are easy to adapt to any environment. We have experience with interfaces to products of all major vendors including Ericsson, Lucent, Nokia, Nortel, Cisco and Siemens.

With such open interfaces it is not necessary to limit CoBilAS’ use to a certain environment like GSM. Those interfaces give you the unique opportunity to handle all imaginable transactions within the telecommunications area, from fixed line telephony to internet access. Our flexible design has even convinced customers from completely different businesses to think about relying on CoBilAS for their billing and accounting. The basic technology we use for our interfaces gives you the opportunity to connect to virtually any external system with a fraction of the efforts necessary with conventional billing systems.