Call Recording in OpenSIPS Using SIPREC Brings Further Value Addition

Updated on: 27 Jun, 2023
OpenSIPS Solution Development

Many technologies are emerging every day, and OpenSIPS is one of them that enables multiple usages in VoIP. It has a wide range of applications, for instance, developing softphones that enable call recording and more similar functionalities. This blog will talk about call recording in OpenSIPS as a feature to record calls passes through the platform progressively and turns from a feature into a requirement. You can leverage the capabilities of OpenSIPS consulting services to develop more efficient technology functionality.

Call Recording is an essential activity for quality assurance. Call centers, service providers, and companies record calls for quality assurance and to keep a watch on interactions. Recording, retrieving, and archiving calls, whether inbound or outbound, can be an IO-intensive process. Call recording improves damage control and strict accountability for your employees, suppliers, and clients.

What is SIPREC?

SIPREC stands for Session Initiation Protocol Recording, a standard protocol that enables real-time recording of VoIP (Voice over Internet Protocol) sessions. SIPREC is designed to simplify the recording of VoIP calls in multi-vendor environments by providing a standardized interface between the recording device and the network equipment.

The SIPREC protocol is used for both passive and active recording scenarios. In passive recording, the recording device simply monitors the VoIP traffic, while in active recording, it establishes a separate RTP (Real-time Transport Protocol) session with the VoIP endpoint and records the media stream directly.

SIPREC offers several benefits over traditional recording methods, including improved scalability, interoperability, and reduced complexity. With SIPREC, organizations can implement a centralized call recording solution that works with a wide range of VoIP equipment, allowing them to streamline their operations, improve compliance, and enhance customer service.

Interested in Implementing SIPREC for Call Recording in OpenSIPS?

How To Easily Handle Call Recording, Retrieving, and Archiving?

The answer is through OpenSIPS Solution Development.

OpenSIPS Solution, with the right set of protocols, equipment, and processes tied into VoIP, solves all these requirements.

The SIPREC standard and OpenSIPS protocol are at the heart of call recording. Major organizations already have some form of VoIP PBX or a call center system to handle communications. Call recording may be available for class 5 Softswitch, but a SIP proxy may not have this feature. It would need RTP Proxy or Mediaproxy media server to extract the RTP stream through a media server.

How Is Call Recording Done?

Control over the call’s RTP/media stream is crucial when recording calls. To accomplish this, we should force the media through a component of network hardware on our platform that we have access to and can use to peak at and extract the RTP stream. Most PBXs already perform this for Class 5 services, but a SIP proxy (like OpenSIPS Solution) lacks media capabilities and requires further assistance from a media server.

The call recording, in that case, is done in three ways.

  1. Passive Call Recording
  2. Active Call Recording
  3. External

Let us understand each of them.

Passive Call Recording

Passive Recording is a type of call recording entirely transparent to a telephone system. The calls can be recorded passively by sniffing(monitoring) and extracting data packets to copy to the recorder.

It is relatively simple to implement but tedious when last grouping and identifying calls. It has no impact on the telephone system at all.

Passive call recording does not affect the calls. VoIP call recording equipment uses passive call recording technology, so your business’s data network will need more capacity to accommodate it. It is one of the significant drawbacks of passive call recording. The requirement for extra capacity on the data network is due to the technology used for “high-impedance” taps for VoIP telephony networks.

Active Call Recording

The better and more streamlined solution is systematic OpenSIPS development integrated with a media server to record calls actively. This process uses a media server to record RTP packets with appropriate metadata, making retrieval and identification easy. But it imposes the additional burden of a different media server to record calls and call routing and processing through the same media server.

This approach makes annotating metadata relatively easy because all the routing-related data is already available; you need to connect it to the appropriate RTP session. This solution’s drawback is that it adds some overhead to the PBX/Media Server, necessitating the implementation of a proper external load-balancing algorithm.


A more refined way is to divert the RTP stream to an external server to record incoming and outgoing calls using the SIPREC protocol. This ideal protocol suits the purpose of sending the RTP stream and metadata to an external recorder without affecting the quality of an ongoing call or the operator even being aware of the fact.

The recorded calls fall under the following classification:

  • Caller
  • Domain
  • Inbound or outbound
  • Group

Since OpenSIPS Solution Development does not have media capabilities, the development incorporates the inclusion of the RTPProxy media server in the recording chain. An authorized supervisor can then use a web interface to access the calls and categorize them further. SIP and RTP work in tandem delivering data through the session-recording client to the session-recording server without the need to balance loads.

OpenSIPS using SIPREC can be implemented in several ways. One is recording in the premises using the SIP trunk/session border controller/SIP trunk/termination to PSTN pathway with SIPREC diverting data at the session border controller to the session recording server. The hosted multi-tenant recording is also possible where data from different streams are channeled to the multi-tenant session recording server.

Wrapping Up

Ecosmob, with its expertise in VoIP development, now takes call recording to sophisticated heights by seamlessly integrating Custom OpenSIPS development with SIPREC. This adds additional value to users at a reduced cost of ownership and with no upfront investment or maintenance burden.

Are You Looking for a Reliable Call Recording Solution for OpenSIPS? Look No Further Than SIPREC!

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