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Two sets of CDRs for the same call: A perfect match or a data disconnect?

By, Kari Bittner

As Telecom managers migrate to SIP trunks and use Session Border Controllers (SBCs), it becomes increasingly important to include SBC data in your overall analysis of routing and traffic. Without it, you’re only seeing part of the story around your calling data and therefore, traditional PBX CDRs create improper costing and cannot be used alone to identify on-net vs. off-net calls.

What is a Session Border Controller?

An SBC is a device deployed in VoIP networks to exert control over the signaling. SBCs create Call Detail Records (CDRs) that provide a clear picture of how calls are routed in/out and to/from your organization’s entire infrastructure. They are designed to control security, connectivity, quality of service, media services and more. The SBC gets its name because it resides on the “border” of a VoIP network. Therefore, it knows how calls exit the network and is able to generate call detail records about that hop-off portion of the call.

Common CDR Reporting Challenges with VOIP

With the growing use of VoIP networks, our customers have come to us with CDR reporting issues that arise due to these conditions:

• PBX CDRs collect important data about the call and who initiated/received it but are unable to determine where the call exited the network when an SBC is involved.
• SBC CDRs know where a subset of calls exited the VOIP network – but they are treated as tandem calls without an extension and therefore don’t know who initiated/received the call.
• These two network components can create CDRs for the same call without a clear ID to connect those multiple CDRs, causing the issue of duplicate, unconnected calls for the same CDR, improper costing of PBX CDRs and inability to identify on-net vs. off-net calls.

SBC Matching Addresses these Challenges

To effectively track granular call detail, the CDR data from the traditional switches is matched with the CDR data from the SBCs, even though there isn’t a specific ID connecting those two types of CDRs. This matching is performed through algorithms that compare start times and durations of the two sets of CDRs.  Calls that fall within the configured matching rules are considered related, thereby enabling reporting on a complete routing of a call in a mixed environment.  When matches are made, key data is transferred between the two matching CDRs so that costing is accurate on PBX CDRs and traffic volumes are accurate on SBC CDRs.  Additionally, with trunk and call type configuration capabilities, telecom managers can easily create call types specifying which traffic is on-net or off-net, for use in call type reporting.

SBC Integration is Critical

To ensure optimal end-to-end data capture, reporting and analysis, it is important that the CDR reporting technology is integrated with the SBCs. For instance, Calero has built integrations with the industry leaders, Cisco CUBE and Oracle Acme Packet, ensuring our customers get seamless data flow and SBC Matching.

SBC Matching is fairly new to many telecom managers and cost accountants. To help you better understand its value and how it can work for you, we will feature the topic at our upcoming Calero World Online event. I invite you to join us for this training session where you’ll learn how to configure SBC Matching, an On-net call type, and related reports.

Sign up today for Quick Start Implementation of Session Border Controller CDRs to reserve your spot.