How To Solve Your VoIP Phone Issues

Symptoms:

• You can hear the other end of the line, but they can’t hear you.
• Your phone refuses to register.
• Phone continues to ring after the call is picked up.

Description:

If you recognise any of the above symptoms, we can almost certainly identify SIP ALG as the culprit. SIP ALG (Application Layer Gateway) is simply a setting within many routers that is intended to inspect SIP messages and exchange their private IP addresses for public ones but frequently interferes with VoIP traffic as a result. This issue is common with consumer-grade routers such as those provided by Virgin Media and BT.

Resolution:

Although quite a common issue and not too difficult to resolve, the method of resolution is different for every model of router, so it will usually be best to:

• Give our customer support team a ring at 0330 122 6000.
• If you’d like to tackle the issue yourself, a quick google for ‘SIP ALG’ appended to the model of your router should present you with the necessary directions.
• Occasionally, the setting will not be immediately accessible through a GUI, in which case you will only be able to access the setting via SSH.
• In some cases, your ISP can turn this off for you.

Symptoms:

• Your VoIP phone appears to be entirely functional, but no audio comes through the handset.
• Issues establishing a network connection.

Description:

A very common issue occurs when cables are connected to the incorrect ports on the back of the VoIP phone. The handset must be wired into the handset port, whilst the ethernet cable should be plugged into the LAN / INTERNET port and not the PC port.

For reference, the PC port is used to connect a PC to the phone, whilst the phone is connected via the LAN port to your network switch or router. This ‘daisy chaining’ of devices will often negatively impact the performance of your PC or otherwise inconvenience you. Changes to VoIP phone configuration often require a reboot of the phone, which means downtime for your PC’s connection. Often, VoIP phones do not have gigabit passthrough, meaning the phone will act as a bottleneck for your PC’s down and upload speeds. In general, therefore, it is best to keep the PC and phone entirely separate on the network.

It sounds obvious, but make sure your cables are plugged into the correct ports. These are not always named intuitively.

Resolution:

• Check that your handset is plugged into the handset port (not the headset port!).
• Check that your ethernet cable is plugged into the LAN port on the back of the phone.

Symptoms:

• Phone isn't receiving any power

Description:

If your phone isn’t receiving any power, or appearing to turn on, it may be that you’re connecting it to an ethernet port because, at your place of work, you’re used to seeing your desk phone with only an ethernet cable plugged into it.

However, the phone would have been plugged into a PoE switch or PoE injector. These are devices that can supply power to a device through an ethernet cable. If you don’t have a PoE switch or PoE injector with which to supply power to the IP desk phone via the ethernet cable, then you’ll need to use the phone’s dedicated power supply.

Resolution:

Without a PoE switch, PoE injector or appropriate power supply for your unit, you will be unable to use your VoIP phone, so:

•  Be sure to purchase or otherwise source one of these from the Yay Store or your hardware distributor of choice.

Symptoms:

• Crackly audio
• Delays in speech
• Generally poor call quality

Description:

Poor call audio quality when using business VoIP is often a result of packet loss or jitter. By virtue of being digital, VoIP converts voice data from analogue sound signals to ‘packets’ of data. If your internet connection is poor, packets can be delayed in arriving at their destination, resulting in packets arriving out of order, which is a phenomenon known as ‘jitter’. If the connection is particularly poor, then packets of data can be lost entirely on the way to their destination.

A poor quality connection results in packet loss and jitter, ruining your call quality.

Resolution:

If you’re experiencing the above issues, the problem is likely a weak network connection. Even if your download and upload speeds seem passable, your actual internet connection might not be particularly stable.

• Try plugging directly into your router, which should help with LAN connectivity issues.
• If this doesn’t work, try ringing your ISP to see if they can solve these connectivity issues for you.
• Your issue may be trickling down from further upstream, in which case your ISP is usually the party best positioned to deal with the problem.

Symptoms:

• The phone is powered on but cannot connect/make or receive calls.
• You cannot find an IP address for the phone on the appropriate page of the phone’s settings

Description

Check if the phone has been assigned an IP address by navigating the on-screen setting for the phone (the method of navigating to the IP address is specific to the make and model of your phone). If the phone has not been assigned an address but is otherwise configured correctly, then it’s not managing to pull one from the network, meaning something is blocking it. This could be a faulty cable or some device sitting between your VoIP phone and the router, like a network switch or power line adaptor, that is interfering in some way with the network connection.

Poor connection quality can result in packet loss and jitter, ruining the quality of your calls.

Solution

• First, try plugging the phone directly into the router to see if your VoIP phone can pull an IP address this way.
• If not, try a new cable, as it may be that your ethernet cable is damaged and, therefore, your router is not able to properly communicate with your desk phone.
• Essentially, your phone is not properly communicating with your network, so you will want to simplify the configuration as much as possible to eliminate any confounding variables and properly diagnose the offending device or cable.

Conclusion

With a VoIP phone system, working remotely should be a breeze. However, these common issues can present a temporary barrier to entry for many. Hopefully, this post has bridged that gap for you and you can get back to being highly productive, even whilst working from home.

Don’t forget, if you ever come across anything you can’t (or don’t want to!) handle then you can contact us.