The customer has reported echo on the line: The user hears their voice repeated back to them after they say something, impeding their ability to hear the person on the other side. This can be heard by only one user or by both.

This is generally not a favorable situation, unless the customer is a dolphin.

Information Gathering

Troubleshooting

     Identify Source of Packet Loss

     Packet Loss From Behind an Edgewater

     Additional Troubleshooting and Next Steps

Information to gather from the customer:

  1. Circumstances of the call–Think in terms of Who, What, When, Where and How:
    1. Who: The parties involved, usually an Originating Party who called out to a Terminating Party
      1. Originating Party (calling number):
      2. Terminating Party (called number):
      3. Direction of issue: Is the echo heard by only one party (Just the caller? Just the callee?) or do both sides hear it?
      4. Scope of the issue:  How many users are experiencing echo?
        1. Single user
          1. If remote, investigate packet loss on network
          2. If in office, investigate physical layer
        2. Multiple users - Investigate packet loss on Edgewater
        3. All users
          1. Site-wide - Investigate packet loss on Edgewater
          2. Enterprise-wide - If in different locations, there could be an issue on the server or back end
    2. What: The context of the call.  Inbound?  Outbound? Internal? External? Is it only certain kinds of calls, or is it all calls?
      1. Direction (Outbound vs. Inbound): Is the echo only on outbound calls, inbound calls, or both?
      2. Endpoint: Method of placing and receiving call
        1. Deskphone:
          1. Manufacturer: Polycom, Yealink, Cisco or other?
          2. Primary Device or SCA?
          3. Hotel/Open Seating host
        2. Remote Office
        3. Softphone
          1. UC-One
          2. Skype
          3. Teams
        4. Cell phone - If a cell phone is involved, poor audio quality could be due to the cellular network.
      3. Application: Was any call tracking application in use?
        1. Unity
        2. ECS
        3. Call center
        4. Receptionist
      4. Any additional details pertinent to the call (Was the user transferred or put on hold?)
        • Any error messages on the phone or application?
        • Headset?
    3. When: Was this a one-time occurrence, intermittent or persistent with every call?  Try to get a specific call example.
      1. Date:
      2. Time (including time zone): 
      3. When did the issue start?
        1. Today at a specific time
        2. Previous day
        3. Does this happen at a certain time of day?
          • If at certain times, could be due to call volume (connection bandwidth) or network issues (network saturation or QoS issues)
          • Any unusual weather conditions such as rain or electrical storms?  Could indicate bad wiring or electrostatic discharge (ESD)
        4. Has never worked since implementation
      4. Does the echo start after a certain period of time, such as after ten minutes?  Does the issue occur only on longer calls?  If so, and the user's remote, this could indicate an issue with Stateful Inspection on the local network's firewall.  Provide firewall guide.
      5. Frequency
        1. Every call?
          1. Check for packet loss
          2. If none, investigate physical layer
        2. Intermittent?
        3. Can it be replicated?
          1. On user's end?
          2. On our end?
    4. Where: Location of each party. 
      1. Remote or in an office behind an Edgewater? (Ask the user, "Are you in the office or remote/at home?")
        • Check phone in OCOM to see what IP address it's registering from.  If the IP can't be found in Nagios, it's probably remote.
      2. Does Evolve own the numbers involved or are they off-platform numbers owned by another carrier? (Some troubleshooting may be necessary to determine this)
    5. How: How was the call initiated?
      1. Direct call: Originating Party dialed Terminating Party directly
      2. Queued call: The call was presented to the Terminating Party through a call center.
      3. Transfer: The Originating Party reached a Terminating Party, then was transferred to a secondary Terminating Party.
  2. Obtain a call example - Call Examples must be from within the past 24 hours so that if needed they can be investigated with underlying carriers.
    • Caller:
    • Callee:
    • Time/Date (including Time Zone):
    • Call Example Verbiage:

                   To facilitate troubleshooting the reported issue, a call example is required. 

                   Please provide us with a specific, recent call example (from within the last 24 hours) of the reported issue, so we can verify its routing and quality.

                   Please include the following information:

                  Caller number: 
                  Callee number: 
                  Date and time (including time zone): 
                  Issue description:

                  **************************Your ticket is now being placed on a HOLD status pending the requested information.

             

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Troubleshooting

  1. Find the call example in OCOM and document the call example and PCAP in the ticket
    1. OCOM
      1. Search by the offnet number.  This is the best way to make sure you get all the legs of a call.  Can search under "User Tracking" or "Calls."
      2. Calls from a softphone like UC-One or ECS will show as inbound.
      3. Is there any packet loss or jitter?  
        1. If so, identify the source
          1. Carrier: Open a ticket with the offending carrier for investigation.
          2. Local network:
            1. If in the office, is there packet loss on the WAN connection of the Gateway/Edgewater? 
              1. If we manage the circuit, open a ticket with the carrier
              2. If customer manages circuit, advise them to contact their ISP and close the ticket
              3. If only one user is having issues, confirm physical layer
                1. If using headset, try with handset and speakerphone  
                2. Replace ethernet cable
                3. Move phone to a known-good location
                4. Any issues with the local switch?
            2. If remote, provide firewall guide and advise the user to call their ISP.
        2. If not, investigate local/physical layer.
          1. If using headset, try with handset and speakerphone 
          2. Replace ethernet cable
          3. Move phone to a known-good location
          4. Any issues with the local switch?

Echo due to the Calling Party 





COMMON CAUSES OF ECHO




This is an example of echo occurring from the calling side. Agent is dialing outbound to end users, and they are complaining that they are hearing echo. End user experience is that they are reporting the agent calling, they can hear them twice. In this case, the caller can hear himself as he is talking to the user. B's volume is so high, the receiver will pick up of what A is saying as well, and will result in an echo for Voice A.



HARDWARE -  Hardware can be a factor in creating echo. It can be found typically at the far end of the talk. Interference can be due to a number of reasons such as poor quality splitters, or damaged wiring ,or poor analog headphones.

FEEDBACK - Feedback typically occurs from the far end telephone, and usually results in the voice traveling back to the mouthpiece from the earpiece through the receiver itself. This can occur when the caller is not holding the handset correctly (against their head) or if the handset is poorly designed. When either occurs, it’s possible for the microphone to pick up sounds from the earpiece and send them back down the line. This occurs as a result of cheap or poorly designed hand/headsets, feedback is a separate concern in and of itself. 

VOLUME - High volume can also cause feedback, which will also result in echo. Adjusting the volume of the phone itself can sometimes have an impact on echo if this is the cause.




Troubleshooting Steps

Not all echo is caused by the carrier.  Sometimes it's due to local equipment or wiring.  Some troubleshooting may be necessary to isolate the source of the issue:

  1. Try to replicate the issue.
  2. Remove variables.
    • If using a headset, try speaker and handset
  3. Move the phone to another, known-good port.  If in the office, and no packet loss is showing on the Edgewater or carrier, it's possible there may be an issue with the cable, port or switch.
    1. If user is using a polycom, please enable Echo Cancellation mode as this will alleviate the behavior. The Acoustic Echo Cancellation (AEC) feature removes the echo of the local loudspeaker from the local microphone without removing the true near end speech.
  4. For customers that have dedicated call recording servers, we can pull their recordings and listen to locate the choppy audio (Note: Don't mention this to the customer, though.  This is just a troubleshooting step on our side) - List of customers that have dedicated servers: Orecx Call Recording Server List
  5. If this is affecting multiple or all users, ensure the local switch is not malfunctioning.
  6. Based on the originating source of packet loss, your next steps may vary:
    1. Client Side
      1. Check for circuit errors, dropped packets
        1. If circuit is EIP responsibility, then open a ticket with the circuit provider
        2. If circuit is client responsibility, tell the customer they need to open a ticket with their ISP/WAN provider
      2. If circuit is clean,
        1. If Evolve owned or managed CPE, check equipment (CPU utilization, physical connections)
        2. If not Evolve owned or managed equipment, request customer to have their IT staff review
    2. PSTN Side - Open ticket with Carrier
    3. Evolve IP network - Document findings and elevate the ticket to the next Tier.
  7. When to send to Tier 2:
    1. Chronic, replicatable issues for which the client pushes back that the issue's on us or they don't believe the issue is from off our platform
    2. Issues that can't be resolved with Tier 1 resources (always present issue in the group chat and check with team leads before elevating to Tier 2)
    3. If the customer's listed on Orecx Call Recording Server List, you can mention this to Tier 2, that recordings can be pulled, but again, don't mention this to the customer.

See also:

Call Quality

 Call Quality Troubleshooting: Choppy or Static

 Documenting Call Examples in JSD

 What is Jitter?