VoIP Call Quality Problems: 7 Causes and How to Fix Them in Dubai Offices

VoIP Problems Are Almost Always Network Problems

90% of VoIP call quality issues in Dubai offices are caused by the network, not the phone system. Here are the 7 most common causes and their fixes.

Problem 1: Jitter (Choppy Audio)

Cause: Inconsistent packet delivery times.

Fix: Enable QoS on your router and switches, prioritising VoIP traffic. Put IP phones on a dedicated VLAN.

Problem 2: Echo

Cause: Acoustic echo from speakerphone or poor echo cancellation configuration.

Fix: Enable echo cancellation on the IP PBX. Replace low-quality speakerphones.

Problem 3: One-Way Audio

Cause: Firewall or NAT configuration blocking the RTP media stream.

Fix: Disable SIP ALG on your router. Open RTP port range (UDP 10000 to 20000) on firewall.

Problem 4: Dropped Calls (After 30 or 60 Seconds)

Cause: Firewall drops the SIP session due to idle timeout.

Fix: Increase firewall SIP session timeout to 1800 seconds. Enable SIP keepalive on IP PBX.

Problem 5: No Audio At All

Cause: SIP registration failed — phone is not connected to PBX.

Fix: Check phone registration status in PBX admin panel. Verify SIP credentials.

Problem 6: Calls Cutting Out Under Load

Cause: Insufficient internet bandwidth. Each VoIP call needs approximately 100kbps (G.711).

Fix: Upgrade internet if you have 20+ concurrent calls. Switch to G.729 codec for bandwidth efficiency.

Problem 7: Poor Quality on External Calls Only

Cause: SIP trunk provider quality or codec mismatch.

Fix: Check SIP trunk provider status. Ensure G.711 preferred for external calls.

SAS IT installs and maintains VoIP systems across Dubai. Contact us | +971-526716178

*Related: IP Telephony Dubai | Networking & Security Dubai*