PDCP Discard Timer

Hi All!
Any tips on how to check PDCP discard timer in network?
Vendor is Huawei.



This is eNodeB level, right?

Yes. With groups as per QCI.
Lst CELLQCI and Lst QCI, check these commands too.
In DT logs you will find in a best way.


Yes this for drb.
And Lst srbpdcpparagroup is for srb.
Ack will be non gbr.
Un ack will be gbr except ims.

For Srb there are SRBCFG and SRBRLCPDCPCFG.

I see.

Check PDCP discard.
In DL RLCPDCP in non gbr I think infinity is recommended.
Check Hedex, it give suggestions and recommend.

Will definitely do, thanks so much for the tips! :wink:

I suggest to use PDCP discard timer for DRB level.

As infinity for throughput.

Yes let’s use 150 ms.

But infinity gives good throughput. Can it affect other KPIs?

Infinity too high it will impact latency actually use of this timer is like once PDCP PDU pass to lower layer then PDCP start timer and wait for response from RLC layer.
So if we keep lower value of timer, then it get expired early leading to packet discard fast, but will improve latency.
Higher value suggest to improve throughput, mute call but it lead to increase in latency.

1 Like

In Huawei this is recommended in non GBR only, not for GBR.

Yes, we used for RLC UM.

Actually that is my issue: high ping delay!

In non gbr enable smart preallocation.

1 Like

I will set it to 150ms and share the impact with you folks.

Yes, sure.
You have smart preallocation also.
Check erab setup time KPI.