MME Proxy / S1-Flex
MME Proxy distributes S1-AP signalling across an MME pool so operators can add or retire MME capacity without re-planning eNodeB associations, directly implementing the 3GPP S1-Flex model for MME pooling and geographic redundancy.
Key features
- Weighted, capacity-aware load balancing across pooled MMEs
- Transparent S1AP relay with GUMMEI / MME-code based routing
- Graceful MME drain for maintenance without dropping active UEs
- Overload control per 3GPP TS 36.413 S1 Overload procedures
- Active-standby and geo-redundant deployment modes
- Rich counters exported for NMS-UI and third-party OSS
Governing 3GPP & O-RAN specifications
These are the primary specifications this product implements or interoperates against. NgRAN tracks each release train and updates products as specifications evolve.
| Specification | Title / scope |
|---|---|
| 3GPP TS 23.401 | GPRS enhancements for E-UTRAN access — MME pooling & S1-Flex |
| 3GPP TS 36.413 | S1 Application Protocol (S1AP) |
| 3GPP TS 29.272 | MME/SGSN and HSS related interfaces (S6a) |
| 3GPP TS 23.007 | Restoration procedures |
Specification titles are summarised for reference. Full texts are maintained by 3GPP (3gpp.org) and the O-RAN ALLIANCE and are not reproduced here.
Architecture & interfaces
MME Proxy sits between the eNodeB S1-MME termination and a pool of physical or virtual MMEs. It maintains UE-to-MME affinity using the GUMMEI carried in Initial UE Message procedures, and rebalances only at the pool-membership boundary — never mid-session — so ongoing NAS signalling is undisturbed. Deployed in-line as a 2N or N+1 cluster, it is fully transparent to eNodeBs, which see a single virtual S1-MME endpoint.
Reference interfaces
Deployment model
Bare-metal, VM, or containerised (Kubernetes / CNF) — same control-plane logic across all three.