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E2: (2021-05-25) implementing E2APv1.0, excl. the three features added in E2APv1.1. Also no support for RIC-784 (timer handling in E2 control messages), RIC-785 (error indication handling) and no E2 Reset.
Xapp frameworks in general: See xapp writers guide attached to this wiki page: xApp_Writer_s_Guide.pdf (we are in the process of moving the app writing guide to https://docs.o-ran-sc.org.)
Xapp framework for Go: as per link under "xApp framework for Go" in Near Realtime RAN Intelligent Controller (RIC)
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