VoLTE Codec Issues & Troubleshooting?

 

Layer-Wise Troubleshooting Approach for VoLTE Codec Issues:-

Step 1: IMS Registration Check

• Use IMS_Registration_Status

Check if IMS is registered successfully.

Fix: If IMS is not registered, reset IMS settings and verify VoLTE provisioning.

Step 2: SIP Signaling & Codec Negotiation

• Use IMS_SIP_INVITE and IMS_SIP_183_SDP

Check codec list in SDP message (AMR-WB, EVS, etc.).

Fix: If codec mismatch, ensure UE and IMS core support the same codec.

Step 3: RTP Packet Flow Analysis

• Use IMS_RTP_Stats, IMS_Media_Statistics

Check for packet loss, jitter, and latency in RTP flow.

Fix: If high packet loss, optimize QoS, increase jitter buffer.

Step 4: RLC & HARQ Retransmissions

• Use LTE_RLC_DL_AM_PDU, LTE_MAC_HARQ_DL_ACK_NACK

Check if too many retransmissions occur in VoLTE bearer.

Fix: If RLC retransmissions are high, improve network conditions.

 Step 5: QoS & Bearer Prioritization

• Use LTE_EPS_Bearer_Context_State

Ensure VoLTE bearer (QCI=1) has high priority.

Fix: If QCI is incorrect, force correct bearer configuration.