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Cisco Bug: CSCub03033 - 4G devices, in LTE mode not dropping down to HSPA to receive Voice Calls

Last Modified

Dec 26, 2016

Products (1)

  • Cisco ASR 5000 Series

Known Affected Releases


Description (partial)

Customer's internal complaints which indicated that certain 4G devices, in LTE mode, were not dropping down to HSPA to receive mobile-terminated voice calls.
Upon investigation, cu performed a monitor-subscriber, and observed that while CU successfully see the SGs-Ap paging request, and the MME does send the S1AP paging request to many eNB in the tracking area, the eNB that the UE is actually communicating on never gets paged.
Further testing seems to have shown that the issue exists for both CS-initiated paging and PS-initiated paging.


CU do not use Heuristic paging on their network, so when a UE needs to be paged, CU assumption is that the MME should page all eNB in the TA.
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