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MME is not responding to S1 setup request message

+2 votes

What is the eNB behavior in-case MME is not responding to S1 setup request message (ie. MME is not sending S1 setup failure or success).

posted Aug 12, 2013 by Deepak Dasgupta

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1 Answer

+1 vote

Googled and found the following -

The specifications say that if the eNB receives “S1 setup failure” message, it includes the indicated time before retaining the S1 setup towards the same MME (TS 36.413). They does not say anything what happens if there’s no message incoming from the MME, but I presume, that it is up to the vendor that shall define another timer which the eNB uses (at expiry) to resend the message to the same MME. Another option is, that the eNB at this “vendor dependent timer” expiry will try to reach another MME (if connected to more than one), by sending “S1 setup request” message.

answer Aug 12, 2013 by Salil Agrawal
Similar Questions
+1 vote

Generally MME serves a group of tracking areas and belongs to at least one PLMN.
Lets assume, MME receives S1-setup request from eNodeB with the list of supported TAs.
Now, there are three possibilities as captured below.
1. All supported TAIs match at MME
2. Not even a single TAI match at MME
3. Few TAIs match at MME

I want to know, what MME will do for case 2 and case 3 ? How it will respond to eNodeB ?
If MME responds with S1-setup failure then what would be the cause value ? I did not find any reference in 36.413 for these scenarios.

+1 vote

I found two MME UE S1-AP IDs i.e. MME UE S1AP ID (Mandatory) and MME UE S1AP ID 2 (optional).
I got why mandatory one is present but what's use of optional one.

Can someone please explain it ?

+2 votes

I have a use case in which
ENodeB sends "S1-Setup Request" message to MME. TAC within the request is unknown for MME but at least one PLMN from the list of broadcasted PLMN is known by MME. How MME shall react ?

0 votes

Hi All,

I have a query regarding S1 setup procedure.
If MME receives S1 setup Request message from same eNB twice (Assuming the S1 connection is already up), what will be the behavior of MME in this case.
Will it erase both UE and non-UE related application data? Or does it send S1 setup failure message?

Thanks in advance.

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