LTE: What PPF signify ?

Question

Authentication Request message carries AUTN value which in turn has AMF field. What does it mean ?

Answer 1

PPF flag is very useful at MME. Whenever MME is not sure about the location of an UE at tracking area level it clears the flag and doesn't perform paging for that UE. Usually it happens, when periodic tracking area update timer expires at MME for an UE.

Note: In such situation, if SGW sends downlink data notification to MME, it responds back to SGW with the downlink data notification failure indication message.

If you still have any doubt/related question, please feel free to ask.

Comments

Hi, After the downlink data notification failure sent to the SGW, what happens if after some time there is more traffic downlink to the EU. Should the SGW send a downlink data notification to the MME?

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This is a very old thread, probably ask a fresh question to get the peoples attention.