business voip


System Status
Support Hours (AZ time zone)
Monday-Friday: 5am-6pm
Saturday: 9am-1pm
Toll Free: (800) 285-7995
Submit a Ticket

Archive for the ‘Troubleshooting’ Category

How do I resolve a dropped call?

A dropped call is a call that ends before intentionally hanging up.  You will usually hear either a fast busy signal or lost audio.

Types of Dropped calls

Call Drops and you hear a fast busy sound: a valid call is made and connection is established, then after a period of time the call goes directly to a fast busy signal. In many cases this is caused by multiple routers on the phones’ network or a firewall not set up to accept SIP or VoIP traffic. 

Call Drops to dead air (No Audio): can be caused by anything from the lack of adequate bandwidth to support VoIP, to routing issues with the Internet Service Provider.  In many cases problems with your outgoing audio dropping can be due to an insufficient bandwidth, especially if after maintaining the connection the audio comes back.  Sometimes this can be best described by a "choppy sound" or periods of no audio.

Calls that cannot complete or don’t go through: If you experience a fast busy or other message that indicates a failed call, when calling certain numbers but not others, then most likely the issue is with the way the call is being handled by your provider or another carrier.

Calls that get cut off: This happens because of the algorithm that is used to create a comfort noise during calls; with VoIP, the dial tone and other sounds are created or imposed. This also may be caused by insufficient bandwidth.

If you have experienced a dropped call, check the following:

1. Bandwidth information: We will first want to see what your network capabilities are currently. To do this, please run ping tests multiple times to verify consistency.

Visit to complete testing

  • Download Speed:
  • Upload Speed:
  • Packet loss:
  • Ping:
  • Jitter:

It’s best to run these tests during actual times of poor audio or dropped calls. Testing a healthy or fully working network won’t necessarily direct us towards a resolution.

If you discover packet loss or any irregularities in the network, contact your Internet Service Provider and ask them to test the connection to your modem.  If your network connections are sufficient, please fill out all information below so our Support Team can continue troubleshooting.

2. Provide network information (All of the information will better help us determine dropped call issues).

  • ISP:
  • Modem (make/model):
  • Router (make/model):
  • WAN IP:
  • Switches [(If applicable) make/model]:
  • Download Speed:
  • Upload Speed:
  • Packet loss:
  • Ping:
  • Jitter:

3. Phone information.

  • Phones (make/model):
  • Do the phones have Static IPs?
  • Have you verified all the phones are connected to the same network?

List 1 example of a dropped call. If none are available right now, please make a note of future dropped calls that come in, so that this can be further investigated. List any examples in this format:

CALL EXAMPLE: From XXX, To YYY. Call dropped @ X:XX PM (GMT) on 12/8/12. Duration:

If you have any questions directly ask an Amazing Service Team member here or email us at

How do I identify SIP ALG?

Many of today's commercial routers implement SIP-ALG (Session Initiation Protocol – Application-Level Gateway), with this feature enabled by default. While ALG could help in solving NAT related problems, the fact is that many routers' ALG implementations are wrong and break SIP (including VoIP).

ALG understands the protocol used by the specific applications that it supports (in this case SIP) and does a protocol packet-inspection of traffic through it. A NAT router with built-in SIP-ALG can re-write information within the SIP messages (SIP headers and SDP body) making signaling and audio traffic between the client behind routers and the SIP endpoint possible (or impossible when used incorrectly).

You may be affected by SIP-ALG if you run into these scenarios:

  • One way audio on calls
  • No audio
  • Phones dropping registration
  • Callers go straight to voicemail for no known reason
  • Random error messages when your number is called (e.g. “The caller you have dialed is no longer in service”)

Nextiva SIP-ALG Detector Tool

If SIP-ALG is detected, many routers allow users to disable it.

If you have any questions directly ask an Amazing Service Team member here or email us at

What is Double NAT?

Double NAT, or multiple routers on one network, is when two or more Routers’ Network Address Translations (NAT) are placed one after the other. Double NAT is common with computer use and web browsing, but is not recommended for VoIP.

Double NAT (Double Routing) is most common when you connect an additional router to the existing router or gateway your Internet Service Provider gave you.

Here’s an example of a simple network with one gateway (say DSL or Cable modem). The gateway has a public (WAN) IP address and does NAT. All computers that are connected to this gateway get assigned a private IP address. The gateway routes the data from and to the computers connected to it. If you have more than one router, the Network Address Translation is placed one right after another, creating a Double NAT.

This can cause intermittent issues, including:

  • One way audio on calls
  • Phones dropping registration periodically
  • Transfers not completing successfully
  • Error messages when dialing a number
  • Hunt groups not working properly
  • Calls dropping involuntarily

If you have any questions directly ask an Amazing Service Team member here or email us at

I am unable to make or receive phone calls.

If you are unable to make or receive phone calls, there are several things that should be checked:

  • If you have Firewalls or other security devices on your network, they may not be recognizing the information from Nextiva’s servers as safe information.
  • Double NAT – See Double NAT troubleshooting
  • SIP-ALG –  See SIP-ALG troubleshooting
  • Phones not registered
  • No Internet Connection
  • Phone/MAC not registered to a user or not recorded correctly – See Setting up Users

If you have checked each of these and are still unable to make or receive phone calls, please contact our Amazing Service team at 800-285-7995 from 5:00am – 6:00pm AZ time Monday-Friday, or Saturday from 9:00am – 1:00pm AZ time. Or, simply email us at

Nextiva Logo

Business VoIP Help Center

phone-icon(800) 799-0600 Sales phone-icon(800) 285-7995 Support
Nextiva is the leader in Business VoIP Services. Copyright 2014 Nextiva, All Rights Reserved,
Terms and Conditions, Privacy Policy, Patents, Sitemap