Support/troubleshooting procedure

Technical requirements

1. Suitable data connection

  1. Minimal bandwidth both up and down per voip call: >100Kbit/s
  2. Latency: <70ms
  3. Jitter: <10ms
  4. Packet loss: <0,5%

Use these or other tools to check your connection quality:
Visualware VoIP quality

2. Suitable router

  1. User friendly webportal
  2. Option to enable remote access
  3. No VoIP/SIP functionality enabled on router
  4. No POTS/PSTN ports
  5. No Active firewalls
  6. No SIP stacks (Software that simulates ATA on modems)
  7. No SIP-ALG

3. The right configuration

  1. The NAT should be symmetric and NAT keep Alive on the phone should be switched on (4-byte packet, NOTIFY or OPTIONS)
  2. In case of NAT the SIP packet should, upon arrival at the registrar, contain IP addresses following the rfc1918 range in the following places: 1st Via header, Contact header and All c= addresses in the SDP.
  3. Do not allow Fragmented packets
  4. Have the ability to set up QOS on all (network) devices so that VoIP traffic is given priority.
  5. Firewall: Allow port 5060 and 8060. All traffic goes over UDP. (allow both inbound and outbound)
  6. Firewall: RTP is used for the transport of the audio data. The traffic can come from any IP address. Many times the voip device dictates which range is being used. In a firewall, this can therefore only be filtered by the local destination port, not on the remote IP. Configure your phones and/or firewall with two ports per concurrent call and allow inbound and outbound traffic to / from these ports to / from any IP address ( RTP is using exclusively UDP (1024 - 65535)
  7. Firewall: Always block inbound and outbound http/https ports to phones.

4. Troubleshooting

  1. Check the attendant console and/or voip phone logs and make a brief summary of your findings.
  2. Make a pcap trace and a brief summary of your findings

5. Check for existing problems

  1. Check our helpcenter for existing problems, solutions and workarounds.

Escalation IPerity Support

  1. If conditions 1–5 are met please provide a report of these points. Also include the following data.
  2. Client name
  3. From which number is dialed
  4. To which number is dialed
  5. Date & Time (24 hour format and timezone)
  6. Exact steps to reproduce the issue
  7. Possible screen recording / movie of the behaviour
  8. Precise version of any hardware, firmware and software used (phone, browser, device)

Email this to:


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