Another popular issue where VoIP engineers are involved in
troubleshooting is PSTN call failures. Both inbound and outbound PSTN
calls are required in almost all the organizations, and most of the
PSTN connectivity happens through a voice gateway using a SIP trunk
with the IP telephony service provider or with the ISDN protocol for a
T1 or E1‑PRI. If these components or the gateway itself are not
configured correctly, you can expect PSTN call routing issues.
So make sure you follow the IP telephony service provider specific
configurations to ensure both incoming and outgoing calls are going
through the gateways successfully. Unused networks led to the
invention of VoIP calls. When an overused,
congested network causes call drops, it's all about striking the right balance.
Make sure the calls get enough bandwidth end‑to‑end to complete.
Adequate network planning is the key here. All the network devices
and servers need power to operate obviously. If there is no power
supply to either the call routing service or any other network device
such as a switch or router, the call gets dropped.
So, make sure power backup is in place to support VoIP
infrastructure to avoid any such issues.
Another problem you may encounter is a device failure. Each web
component like the call processing server or any network device
such as switches, gateways, or firewalls may crash causing the
VoIP calls to fail as well.
Therefore,
crafting a solid device redundancy plan is the key to success in this
regard. Call drops are also caused by the firewalls.
Imagine if the firewall is configured to block certain type of
traffic, like RTP, it can cause calls to be dropped.
So allowing VoIP traffic end‑to‑end is very important.
If two devices use different codecs to encode and decode the audio data,
there may be compatibility issues that require transcoder resources to
translate between two different codecs. Imagine if transcoder resource are
limited or not available at all, such codec mismatch will cause call
failures. Sometimes the background noise and echoes are so strong, only
they are heard loud and clear. And echoes are like having a conversation
with yourself.
They're like the uninvited guest on a VoIP call. Expecting the end
users to always mute their microphone when they are not speaking isn't
always a good solution, so you would often find yourself
troubleshooting such issues as a VoIP engineer.
Investing in soundproofing and a good headset to avoid any unwanted
background noise and echo is a good idea. Additionally,
with the noise and echo cancellation feature,
you can keep them at bay.
These features are available in many software‑based
endpoints like in Cisco WebEx, Microsoft Teams, and Zoom applications.
Sometimes the noisy calls are due to the introduction of a
signal or voltage somewhere in the VoIP network, such as a
loose wire or different power supplies.
You will have to isolate the device causing the noise or static, and this issue can be quite time consuming.