When a business call breaks up, write down what happened before trying another fix. A phone replacement may help a faulty handset, but it won't resolve every audio problem. The useful first decision is whether the trouble follows one person, one device, or a wider group of calls.
Find the pattern before trying a fix
“Bad audio” leaves too much open. Choppy speech has gaps or clipped words. With one-way audio, one person can hear the other, but the other hears nothing. A delay is different again: both people hear the conversation, but keep talking over each other.
Ask which side heard the problem. If customers say your voice breaks up while you hear them clearly, record that distinction. Note whether the trouble began immediately, after a transfer, or partway through the conversation. These observations help support choose what to investigate.
On a quiet test call with a willing coworker, compare the headset with the handset or speakerphone. Keep the conversation free of customer information. If only the headset sounds bad, report that result before anyone orders a new phone.
If several people are affected, ask whether they work in the same area and whether the problem occurs on internal calls, outside calls, or both. Avoid changing several things between tests. A result is easier to interpret when the phone, location, and type of call are clear.
Source: Cisco: Troubleshoot Jabber Audio Issues with Wireshark.
Why a speed test doesn't settle it
Internet calling depends on small pieces of audio arriving in time to be played. Missing packets or uneven arrival times can produce broken or robotic speech. A call may connect while its audio has a separate problem: the instructions that establish the call and the voice itself do not always follow the same path.
That is why a download-speed result alone is insufficient evidence that the call path is healthy. Give support the times of affected calls so it can compare them with network and phone-system records. If problems coincide with large uploads or only occur over Wi-Fi, include that observation as a clue, without declaring it the cause.
Source: Cisco: Troubleshoot Jabber Audio Issues with Wireshark.
Send a small, usable incident record
For each recent example, record the date, local time and time zone, the affected extension or device, call direction, and exactly what failed. Add whether a transfer was involved and whether other employees had trouble at that time. A few specific examples are more useful than a long account of every suspected cause.
Provide phone numbers or call identifiers only through your provider's approved support channel. Leave customer names, conversation content, and recordings out unless support needs them and your business authorizes the sharing. Diagnostic captures can contain call audio; let the technical team handle their collection and access.
Ask support for the next controlled test and who owns it. Leave firewall rules, phone resets, and network changes to the person responsible for those systems. If calls remain unreliable, have the manager and phone provider agree on a temporary call-handling arrangement, including how staff will return missed calls.
Source: Cisco: Troubleshoot Jabber Audio Issues with Wireshark.