More on the pairing of RNC-Id and LAC:
We've discussed that the CN should be manually configured for which RNC-Id belongs to which LAC, in order to find the correct SUA link to page on upon having the to-be-paged subscriber's LAC.
Turns out: even though only the RNC-Id is sent in the id-Reset message, both the RNC-Id *and* the LAC are transmitted in an InitialUE message.
So we can actually record the LACs as well as the RNC<->LAC mappings from the InitialUE messages (like Location Update Request) and don't need to configure them manually.
Does that sound reasonable?
We can still keep the manual vty config of RNC<->LAC mappings to detect errors in the field configuration from InitialUE messages.
~Neels
On Tue, Apr 05, 2016 at 02:03:54PM +0200, Neels Hofmeyr wrote:
Turns out: even though only the RNC-Id is sent in the id-Reset message, both the RNC-Id *and* the LAC are transmitted in an InitialUE message.
For the record, see the RANAP spec (3GPP TS 25.413 version 12.4.0 Release 12) chapter 9.1.33, which lists all of Global RNC-ID, LAI and SAI IEs as mandatory, where both LAI and SAI include the LAC, also mandatorily.
It's interesting how LAI and SAI are mostly redundant, yet both are mandatory.
~Neels
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Neels Hofmeyr