EPS ⇄ 5GS Interworking over N26
This is where the two references meet. Part A is the Huawei EPC+ core (CloudUSN MME + CloudUGW); Part B is the Huawei 5GC SA core (UNC + UDG + UPCF + UDM). The N26 interface between the MME and the AMF, plus four combined network-element pairs, let a subscriber move seamlessly between 4G and 5G. Every feature ID, message, MML parameter, software-parameter impact level and counter below is extracted directly from the CloudUSN HedEx library — nothing invented.
What the N26 Interface Connects
Verbatim — CloudUSN → Feature Guide → WSFD-011117 N26 interface. Definition, benefits and the application scenario, exactly as Huawei documents them.
Interworking Architecture — the N26 topology, live
The EPS and 5GS topologies fused into one. Switch the view: see the N26 signalling tunnel light up, watch the four combined NE pairs converge, or drop N26 to see what interworking without N26 looks like. Node placement, interfaces and the combined-node model are verbatim from WSFD-110307.
WSFD-011117 — N26 interface
The full feature anatomy, verbatim: definition, benefits, scenarios, the NEs involved with their supporting versions, application limitations, the implementation principle and 3GPP standards compliance.
WSFD-110307 — Network Reselection Between LTE and 5G
Idle-mode (ECM-IDLE) mobility: EPS-to-5GS and 5GS-to-EPS cell reselection. Note the combined-node Overview — UDM+HSS, PCF+PCRF, SMF+PGW-C, UPF+PGW-U — and the licence control item.
WSFD-110308 — PS Handover Between LTE and 5G
Connected-mode (ECM-CONNECTED) mobility: the LTE-to-5G and 5G-to-LTE handovers that keep the data session alive across the RAT boundary — the feature that requires N26.
WSFD-110309 — VoLTE Continuity Assurance
Keeping a voice call up across the 4G/5G boundary during interworking — verbatim.
Interworking-5GS-Indicator — the subscription switch
The Diameter AVP on S6a that tells the MME whether 5GS/EPS interworking is subscribed for an APN. Verbatim IE description and reference standard.
Mobility Call Flows — walk each procedure, step by step
The four interworking procedures as animated message-sequence charts. Pick a flow, press Play, and watch the UE move between the EPC and the 5GC across N26. Every step description is the exact sentence from Huawei's System Implementation section — nothing paraphrased.
Configuring & Commissioning the N26 Interface
Huawei's own configuration and commissioning tasks for the N26 interface on the CloudUSN, verbatim.
N26 Policy MML Reference — every command, every parameter
The two managed objects that govern interworking on the CloudUSN: the local interworking policy (N26IWKPLCY) and the combined gateway selection policy (N26GWSELPLCY). Each command carries its verbatim Function, a real MML example, and every parameter with value range, default and configuration notes.
N26IWKPLCY — Local Policy for EPS/5GS Interworking
N26GWSELPLCY — N26 Combined Gateway Selection Policy
Interworking Software-Parameter Ladder — sorted by Huawei's own impact
The CloudUSN software parameters that tune EPS/5GS interworking — from the master switch for interworking without N26 to the fine control of authentication, security and indirect-forwarding tunnels on the 5GS-to-EPS path. Sorted by Huawei's Impact Level; each shows its recommended value, initial value and range. Filter by impact or phase.
Interworking Counters — measure the bridge, per cause
The CloudUSN counters that measure inter-RAT inter-CN mobility between LTE and 5G — outgoing, incoming, and the per-cause handover-failure taxonomy that tells you why an interworking handover failed. Every counter name, description and measurement point is verbatim.
.hdx is a ZIP archive of
profile.xml, resources/navi.xml and per-topic HTML. Every string on this page was parsed
directly out of the CloudUSN V100R020C60SPC100 issue 04 library — the text here is the text in the library.
This page connects Part A · EPC/NSA and Part B · 5GC/SA.