How to check Latency in EN-DC in the network?

[Ankur]

Hi Friends.

If there is EN-DC in the network and want to check Latency then how can I check?

If I do ping test, then it will check 4G or 5G?

Admin note: this post was updated with image below.

[ran_core_consultant]

You will need to see which bearer is being used for default data, i.e. is it 4G or 5G.

It slightly complicated but you can infer it.

For instance look at the DSCP markings on ping response.

Assuming DSCP for 5G bearer is different to 4G, that might be one clue…

[Ankur]

Thanks.

If a drive test engineer is in the field, and doing these tests, then how can he identify?

In other words, if he wants to check Latency in EN-DC case, how can he check on filed?

[suraj_kumar1]

Latency is bulky topic.

You have to calculate:

1. UE Processing time.
2. UL scheduling time - Scheduling Request [periodicity 5 / 10 / 20ms]
3. Frame Structure in use [FDD/TDD] [if TDD then which Slot has allowance]
4. RAN Processing delay [Individual Component involved - RU,CU,DU respectively]
5. Each RAN Component distance.
6. CUUP to UPF.
7. UPF to Speed test/ping server.
8. Repeat vice versa.

This is overal RTT calculations.

Now if in EN-DC case you are referring to DL SPLIT then definitely packets will distribute in DL irrespective of packet size [here implementation matters for DL split on ping size 64bytes,128bytes, 256 bytes,512 bytes,1024 bytes & 1440bytes ]

One has to go to UE PDSCH STATUS- Packet - for DL ping.

UE PUSCH Status on UL ping with both NR & LTE Leg together.

@ran_core_consultant

It slightly complicated but you can infer it.

For instance look at the DSCP markings on ping response.

Assuming DSCP for 5G bearer is different to 4G, that might be one clue…

DSCP is for QOS packet mapping, with such small size packet mostly logic from Transport , Core and ran will be delivered under same logic of QCI9/8/6

For NGBR [QCI:9] you may have different DSCP marking again this Transport decisions.

[Chetan_Suryawanshi]

@Ankur

If a drive test engineer is in the field, and doing these tests, then how can he identify?

Which Handset he use?

JIO having SA so not showing for NSA shows state of EN-DC.

[ravi_satyam2002]

@ran_core_consultant

It slightly complicated but you can infer it.

For instance look at the DSCP markings on ping response.

Assuming DSCP for 5G bearer is different to 4G, that might be one clue…

DSCP marking is done at IP layer to distinguish while forwarding the packet in the transport layer.

QoS is mostly on the application layer which UE is trying to access the service.

[Ankur]

@Chetan_Suryawanshi

Which Handset he use?

One plus 9 Pro.

[ran_core_consultant]

@suraj_kumar1

DSCP is for QOS packet mapping, with such small size packet mostly logic from Transport , Core and ran will be delivered under same logic of QCI9/8/6

For NGBR [QCI:9] you may have different DSCP marking again this Transport decisions.

Each packet has DSCP.

Although is transport feature but its assigned to every packet, small or big.

So ping responses can be inferred.

[Chetan_Suryawanshi]

@Ankur

One plus 9 Pro.

In this case, tell him to check with:

*##4636##*

And take snap of Phone information.

[ravi_satyam2002]

@ran_core_consultant

Each packet has DSCP.

Although is transport feature but its assigned to every packet, small or big.

So ping responses can be inferred.

Indeed it will.

[suraj_kumar1]

@ran_core_consultant

Each packet has DSCP.

Although is transport feature but its assigned to every packet, small or big.

So ping responses can be inferred.

Each packet has DSCP under defined QOS marking.

Do you have any mechanism for Lets say QCI Marked with DSCP marked →
“ping” packets
“streaming” packets
"ftp " packets.
?

Under same QCI!

[ran_core_consultant]

From what i know DSCP is same per QCI for all packet types.

I.e. ping, data, stream they are all transported with DSCP.

[Ankur]

@Chetan_Suryawanshi

And take snap of Phone information.

Here it is:

[Chetan_Suryawanshi]

It’s on 4G.

Try to get 5G the it’s showing.

[Ankur]

How without downloading or uploading any file?

[Chetan_Suryawanshi]

Check this ex.

[Hainm]

@Chetan_Suryawanshi

JIO having SA so not showing for NSA shows state of EN-DC.

From 4G to 5G SA, do we need Core network to activate or change sth for SIM card?

[Chetan_Suryawanshi]

No need to change SIM card.

[LordGm]

Correct, no need to change SIM card.

[Hainm]

How about Core, need to modify the 4G SIM?