Section: 4.8.1 Network Configuration for Interaction with UTRAN/GERAN
Content: GPRS idle mode mobility within GERAN or UTRAN and also between GERAN and UTRAN specifies a set of sequence number handling functions, e.g. the exchange of sequence numbers during Routing Area Update procedures. EPS idle mode mobility procedures don't specify any such sequence number mappings for IRAT mobility scenarios. To avoid interoperation issues a network that deploys E-UTRAN together with GERAN and/or UTRAN shall not configure usage of the GPRS feature "reordering required" for PDP contexts of PDP type IPv4, IPv6 or IPv4v6. Also the network shall not configure usage of lossless PDCP of UTRAN and the GERAN SGSN shall not configure usage of acknowledged mode LLC/NSAPI/SNDCP.