VoIP and Hosted PBX systems are the next big thing for SMBs. Unfortunately, as with any new technology there are some growing pains, and some of you who have made the switch might be frustrated if it turns out your system doesn’t work. But there is good news; if you understand what is affecting your new system, it can be relatively easy to fix. If you are experiencing dropped calls, choppy audio, or the person you are talking to keeps asking you to repeat yourself, please consult this list for possible solutions.

First off, here’s a few terms to know, when dealing with VoIP issues:
QoS (Quality of Service): Gives priority in advance to certain packets in a network traffic, specifically, in our case, VoIP packets.
Jitter: Audio that drops in and out is called “jitter.” In technical terms, it is the variation of time that it takes for packets of audio to be received
Bridge Mode: When your ISP provides you with a modem and wireless modem in one device, it may not be compatible with your VoIP phones. Your ISP can put the modem into “bridge mode,” making it only a modem, and turning off NAT system, firewall, and DHCP.
NAT: Network Address Translation. A NAT router translates network coming and out of private networks (LAN) to the public internet. A NAT is also known as a firewall. The process of data safely going from the public internet into a private network without dropping packets is called “NAT Transversal.”

Check if your router is incompatible:
Your router might not be compatible, for various reasons, including, perhaps it won’t allow phones to register, cannot disable SIP ALG (Application Layer Gateway), or does not have a properly configured QoS. It is more likely that you will have a problem if you have a modem and router in one. Here is a list of devices that we at GetVoIP have determined to be incompatible.

Actiontec

GT704WG

Apple

Airport Extreme Wireless G Model

Apple

Time Machine

Asus

RT-N66U

Belkin

F5D and F7D Series (F5D7234, etc.)

D-Link

DIR825, DIR835
DIR615, DIR600
WBR-1310
BEFSR Series (BEFSR41, BEFSR81)
RVS4000

Cisco/Linksys

E4200 (HW v1)
E3200 (HW v1)
WRT120N
WRT160N
WRT350N
WRV200
WRV210
WRT54G WRT54GX WRT54GL WRT54GS

Motorola

MSTATEA

Netgear

Pro Safe Series,
CG814WG or CG814WT or CG814WCOM
DG834G
FVS318, FVS318
WGR614
WGT624
WNDR3300, WNDR3700
WNR2000, WNR3500L, WNR834B Ver.2
WRN2000,

Thompson

TG-585

Check Your Bandwidth
Disable or stop any devices or operations that take up bandwidth, such as downloading files, streaming music or using devices over Wi-Fi. Then test your bandwidth using the speed test tool. If your upload speed is less than 90 Kbps, you can expect some loss of audio quality. Talk to your VoIP provider to see if they have a bandwidth saver codec option, or talk to your ISP and upgrade your service.

Upgrade Your Firmware
Many VoIP issues have been fixed in newer firmware versions. To upgrade your firmware, download the file from the web page of the manufacturer of your router. Under the administration settings, upload the file, install and reboot. In very rare cases, you might have to downgrade the firmware.

Check the Battery
Some routers have battery backups. While this can be a good thing, if you’re having issues with VoIP you want to have a hard reset, which the battery stops. Note that most routers do not have battery backups.

Put the Modem into Bridge Mode
Disable the router features built in to your modem, and use a different router.

Disable or Enable QoS
Quality of Service is designed to give priority to certain network traffic. But if there is too much network traffic, the system can actually be overwhelmed and force the router to reboot. Test your system with and without QoS. You can do this in your router’s admin page.

Check Your Firewall/NAT
In your router’s admin page, you can disable your firewall protection reboot your devices and check to see if you can successfully make calls.

If you have a problem with your VoIP service, it’s likely to be solved by one of the solutions listed above. While any change in the way you do business can seem new and scary, rest assured that VoIP will save you time and money in short order. Also, note it may simply be the service being output by your provider, in which case the solution is simply find a new provider.

Finally:
Share your experience, as others will get to gain from what you learned along the way. Talk about issues, fixes, and unexpected surprises, too. Other subscribers may be going through the same thing, and would love to know your experience. Review here.

Related:
Power Over Ethernet Guide – 7 Potential Issues
How to Combat SIP Trunking Compatibility Issues
WiFi VoIP Phone: To Use or Not To Use