Packet Loss_QCI1

What parameter setting need to check to improve Packet loss at QCI1.
Vendor is Huawei.

check below parameters to improve packet loss (QCI1)

if VoLTE Packet Loss Due to HARQ Reach the Maximum Number :
enable :DlRetxTbsIndexAdjOptSwitch to decrease for the last two retransmission

If VoLTE Packet Loss in Heavy Traffic Scenario :Reduce initial power for PUCCH .

UlVoipRblerControlSwitch: enable this switch it will decrease the voice packet loss rate caused by uplink HARQ retransmission failures.

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Can anybody share their best practices to improve VoLTE UL packet loss, other KPI in VoLTE and LTE are fine.


Try these Optimization actions:

  • Verify transmission QoS issues. Remarking of packtes having QCi-5 (signiling) to QCi-0, can impact packet loss and VoLte Call Delay.
  • Verify botlenecks in transmission (twamp can be a good tool to get it, or a simple ping test using packets of 1500 bits).
  • Verify your enodeB and transport routers MTU settings ,by having all with the same setting, will avoid packets segmentation and packet loss.

There are some features that can help on that, I will use here, Huawei basis:

  • Volte Frame Recovery;
  • Volte Rate Control (but this can impact your MOS);
  • Turn-off the feature frequence selective, for avoiding unecessary QCI feedbacks in the UL;
  • Verify your TTI bundling setup and its correlation with other features as for example VoLte Coverage Enhancement (Huawei basis).

I hope it helps.

Hi @Pirm,
Thanks will see transmission/transport bottlenecks if present.
Just to tell: this issue is Ericsson specific.

Any improvement observed in BLER?

it will help in case of interference and high UL BLER, it will reduce the TBS size, then reduce retransmission.