Skip to main content
  • Products
    • Overview
    • Features
    • Screen Capture
    • Quality Management
    • Speech Analytics
    • Recording Announcement
    • Videos
    • Online demo
    • Quote
    • Download
  • Solutions
    • Businesses
    • Contact centers
    • Financial institutions
    • Healthcare
    • MiFID II compliance
    • Telecom service providers
    • Traders
  • Compatibility
    • AudioCodes
    • Avaya
    • BroadSoft
    • Cisco
    • Genband
    • IPC
    • Metaswitch
    • Oracle AcmePacket
    • SIPREC recording
    • Sonus
  • Documentation
    • User Guide
    • Administration Guide
    • Developer Guide
    • MiaRec v.3 (old) documentation
    • Resource library
    • Videos
  • Support
    • Submit a request
    • Check your existing requests
    • TeamViewer QuickSupport
  • Blog
  • Company
    • About MiaRec
    • Contact us
    • Our clients
    • Become a partner
    • News
    • Careers
    • Events
Home › Legacy documentation › Passive call recording setup ›
 

What is port mirroring?

Port Mirroring, also known as SPAN (Switched Port Analyzer), is a method of monitoring network traffic. With port mirroring enabled, the switch sends a copy of all network packets seen on one port (or an entire VLAN) to another port, where the packet can be analyzed.

Port Mirroring function is supported by almost all enterprise-class switches (managed switches).

  • A list of switches with port mirroring support
  • How to configure port mirroring

Port mirroring function is best described when comparing  regular switch and switch with port mirroring support.

Figure 1. Regular Switch

Sorry, your browser doesn't support embedded videos, but don't worry, you can download it and watch with your favorite video player!

In Figure 1 you see network  the traffic sent between computers A and B.

The MAC table in the memory of the switch contains information on which port is connected to particular computer.

Switch knows that:

  • Port #1 (first on the left) is not connected.
  • Port #2 is connected to A
  • Port #3 is connected to B
  • Port #4 is connected to C
  • Port #5 is connected to D

When the switch receives a packet from A to B, it routers this packet to port #3 (because B is on port #3).

Other computers (C and D) do not see this network traffic. It is hidden from them.

Conclusion: With a regular switch the network traffic is visible only to computers, which directly participare in a communication. Other computers do not see the traffic, that is not destined for them.

Figure 2. Switch with Port Mirroring

Sorry, your browser doesn't support embedded videos, but don't worry, you can download it and watch with your favorite video player!

In Figure 2 you see the similar scenario: the network traffic is sent between computers A and B.

But there is a small difference: this switch supports port mirroring function. And administrator has configured the switch to mirror to computer D all network packets, which are transmitted between computers A and B.

Computer D is a listener to the traffic. Computer D can be used for network logging or call recording if we have IP phones instead of computers A and B .

Conclusion: Port mirroing allows a particular computer to see the network traffic, which is normally hidden from it.

 

 

How Port Mirroring function is used for VoIP call recording?

 The image below illustrates the usual configuration of network, which enables call recording.

 

Sorry, your browser doesn't support embedded videos, but don't worry, you can download it and watch with your favorite video player!

In this example, one of IP Phones makes a call to a remote phone outside of the local network (whether it is analog phone, cellular or another IP Phone).

Network traffic from IP Phone goes through network switch with port mirroring. The switch sends to MiaRec a copy of every network packet, sent or received by IP Phone.

By using intelligent packet capturing technology, MiaRec detects Voip-related packets inside the network traffic, decodes them and saves audio on a disk.

Read also:
  • A list of switches with port mirroring support
  • How to configure port mirroring
‹ Passive call recording setup up Virtual machine + passive recording ›
  • Printer-friendly version

Legacy documentation

  • Legacy documentation
    • Passive call recording setup
      • What is port mirroring?
      • Virtual machine + passive recording
      • How to configure port mirroring on different switches
        • Cisco Catalyst 2960 Series Switches
        • D-Link DES-3010
        • Dell PowerConnect 2700 Series
        • Netgear FS726T
        • TP-LINK TL-SL2428WEB
      • Port Mirroring in complex call scenarios
      • Switches with port mirroring
    • Manual installation (deprecated) on Linux
      • Installation on Linux (Centos/RedHat) manually (deprecated)
        • Install MiaRec Web portal
          • Install PostgreSQL
          • Install Python 3
          • Install Apache web server
          • Install Redis cache
          • Install MiaRec web application
          • Install Celery task manager
        • Install MiaRec Recorder
          • SystemD start-up script (Centos 7.x)
          • Upstart start-up script (Centos 6.x)
          • Init.d start-up script
        • Install MiaRec Screen Recording Controller
        • Configure firewall
        • Verify services status
      • Installation on Linux (Ubuntu) manually (deprecated)
        • Install MiaRec Web portal
          • Install PostgreSQL
          • Install Python
          • Install Apache web server
          • Install Redis cache
          • Install MiaRec web application
          • Install Celery task manager
        • Install MiaRec Recorder
        • Configure firewall
    • Manual update on Linux (deprecated)
      • Update MiaRec Web portal
      • Update MiaRec recorder files
    • Cisco TAPI integration
      • Add TAPI user for MiaRec application
      • Configure Cisco TAPI TSP driver
      • Verify Cisco TAPI configuration
      • Enable Cisco TAPI interface in MiaRec
MiaRec, Inc. © 2019. All Rights Reserved. | Terms of Use | Privacy Statement | Cancellation Policy