Solution Prerequisites

The following are the solution setup prerequisites.

Hardware requirements

A single VM required for NON-HA deployment.

For HA deployment, two VMs are required. Each machine should have the following hardware specifications. The two VMs will be referred by VM1 and VM2 in this guide.

Minimum requirement


4 cores on each VM


4 GB on each VM


Here is a general formula for the calculation of disk space

File Size = Duration(in seconds) * Sample rate * Bits per sample/8 * Number of channels.

For example, if you have a recording that is 60 seconds long, uses the G.711 codec (which has a sample rate of 8 kHz and a bit depth of 16 bits), and is recorded in mono, the file size would be calculated as:
File Size = 60 * 8000 * 16/8 * 1 = 768000 bytes

Using this formula, disk space can be calculated for number of daily calls and retention period.


1 NIC per VM

Following are the prerequisites for setting up Voice recording solution under different deployment profiles. 

Software Requirements
System Access Requirements
  • Administrative privileges (root) on the host machine are required to proceed with installation.

(lightbulb) Time Synchronisation

Communication between Voice Recording solution, Cisco CUCM, Cisco IP Phones (BIB enabled) carry timestamps. If the system dates and time are not synchronized the system can produce unpredictable results. Therefore, please make every effort to adhere to the following time synchronization guidelines:

Voice Recording solution, Cisco CUCM, Cisco IP Phones (BIB enabled) should have their Time Zone and time configured properly according to the geographic region and synchronized. To configure the time zone, please see the instructions from the hardware or software manufacturer of NTP server. Voice Recording solution and Cisco CUCM should be synchronized to the second. This synchronization should be maintained continuously and validated on a regular basis. For security reasons, Network Time Protocol (NTP) V 4.1+ is recommended.

Port Utilization

The ports mentioned in this section must be open to install the product. 

Source HostDestination Host / Docker ContainerSource PortDestination PortCommunication ProtocolScopeDescription
1VRS HostExpertFlow GitLabany443HTTPSpublic

to clone skeleton project from Gitlab

2VRS HostExpertflow Container Registryany9242TCPpublicto clone the repository from a local gitlab over this port.

For Product connectivity with internal and external components

Ports mentioned in this section should be open for the mentioned product connectivity with different internal and external components.

Source HostDestination Host / Docker ContainerSource PortDestination PortCommunication ProtocolScopeDescription

This port will be used by CUCM to send SIP events to recording solution. This port is opened by SIP Server in recording solution. 

2AnyVRSany443HTTPpublicTo access VRS UI
3anyVRSany8088HTTPpublicTo access VRS Keycloak (Identity and Access Management module)
4Voice gatewayVRSany16386-32768UDP
Range of UDP ports to be used for voice packets streaming from Voice gateway to recording solution.

SIP Trunk configuration

Follow this guide for SIP trunk configuration on CUCM