APN for users to attach to specific MME/SPGW

Hello Experts.

Imagine you have 1 N MME (live users ) and 1 //M MME (test and only 1 test UE should connect) connected to site, without impacting live users, this test SIM should always go to //M MME/SPGW in 4G mode, meaning live users should never attach to //M MME.

If we define a specific APN for this test users, do we guarantee it attaches everytime to //M MME/SPGW?

(both live and test user attaches the same cell)

No, you cannot differentiate MME by APN.

This differentiation needs to happen in the eNB.

Thanks for feedback.

In eNB we will have to 2 MMEs than how to do that?

I think only QCI separation can do that, what I mean QCI9 for live users, QCI129 for only for this test user.

Do you agree?

Of course QCI129 user will have different APN also.

QC129 = QC9 in terms of property.

You can give a try following test step

  1. As //M MME is test MME define a different PLMN B.
  2. Make PLMN B as secondary PLMN.
  3. Use PLMN B SIM in test UE.

By this way UE shall always goes to //M MME.

Yeap not sure if we are eager to do that but definetely a solution.

The reason is those both MMEs will be in live in the future.

What do you think about my previous proposal: QCI129 and diff APN also?

I think the method for MME-selection in eNB will be different depending on the vendor.

I can’t help you much there.

The best I can do is to confirm that the MME-selection is done by the eNB and that selection is made long time before the MS starts talking about APNs.

If eNodeB has N number of S1AP link then at time of attach MME selection is done by a algorithm (you can’t control).

It is based on relative load and available capacity.

Thanks. Yeah, normally MME selection priority is the one which affects MME selection, but in load sharing purposes beside that I don’t know any other method.

MME selection is done by eNodeB.

Defining operator define QCI129 will not help.

Nice topic. Besides MME selection priority is there any other method for Nokia eNBs?

If HSS is not shared between N MME and //M MME then different range of IMSI in //M MME can help.

If test UE attach request goes to N MME then it will reject and next it shall goes to //M MME (not very sure) …

I think HSS is shared.

Live users can also go to //M test and get rejects, this is not wanted.

In MSC there is some certain commands modifes NRI value in TMSI and after a location update susbscriber goes to targeted MSC under the same pool.

I think there might be a similar feature also in MME.

Modify the NRI of test users so they will be routed the specific MME.

Live users they can still go to //M test and get rejects.

I remember that feature for 3G also, but if sombody working from MME can refer the feature for any vendor, would be great.

In this case only modified test users goes.

There is a feature - dedicated core network (decor), if it is supported then it can be used to move subscribers to a specific MME within a group.