Section: 8.3.10.7 Header compression configuration
Content: This IE is included in the message if: a) the UE wishes to re-negotiate header compression configuration associated to an EPS bearer context and both the UE and the network supports Control plane CIoT EPS optimization and header compression; or b) to negotiate header compression configuration associated to an EPS bearer context after an inter-system change from N1 mode to S1 mode when both the UE and the network support control plane CIoT EPS optimization and header compression, and the UE is operating in single-registration mode and has received the interworking without N26 interface indicator set to "interworking without N26 interface not supported" from the network.