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Correlation-id in S1AP

asked 2019-01-29 12:33:38 +0000

Emi Y gravatar image

In S1AP NAS layer, Additional information IE, how do we know that it's correlation-id? There is no indication for it at the standard.

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answered 2019-01-29 20:41:39 +0000

Pascal Quantin gravatar image

updated 2019-01-29 21:24:07 +0000


I based this on 3GPP 24.301 CR 0640 and 3GPP 24.171 (that suggests to use the correlation ID as the Routing Identifier):

The Routing identifier is the Correlation ID, which is defined in 3GPP TS 29.171 [7], so that the MME can map the Routing identifier to the Correlation identifier when the MME receives an S1-AP Transport Message.

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Thanks. Can I assume that when I have S1AP with LPP container, the additional information IE in NAS layer will be correlation-id?

Emi Y gravatar imageEmi Y ( 2019-02-03 13:44:26 +0000 )edit

Based on 3GPP requirement, yes it should be as explained above. Wireshark will decode it as correlation id if the generic message container type was set to LPP. Please do not forget to accept my answer so that it can be easily found by new comers searching the same question. See the FAQ for details.

Pascal Quantin gravatar imagePascal Quantin ( 2019-02-03 18:31:21 +0000 )edit

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Asked: 2019-01-29 12:33:38 +0000

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Last updated: Feb 03 '19