The call recording of SIP lines requires a port mirroring setup, which enables the monitoring of network packets. The port mirroring allows the SIP traffic going through one port on your managed switch to be copied to another port , for packet analysis.
The image below illustrates the general configuration involved in port mirroring.
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Your telephone system will be connected to one port on your managed switch, sourcing the SIP traffic, which will then be configured to send a copy of all SIP packets to another port , connected to one of the network cards on the Echo server.
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