NextEPC provides the MME (Mobility Management Engine), which terminates the S1 interfaces from the eNodeBs cells in the cellular network, and interfaces via S11 to the SGW as well as via S6a to the HSS.
NextEPC provides the SGW (Serving Gateway) which is situated between the MME and PGW. It implements the S11 interface to the MME, and the S5 interface to the PGW.
NextEPC provides the PGW or PDN-GW (Packet Data Network Gateway) element of the EPC, i.e. the gateway between the EPC and the external packet data network, such as the public Internet. It implements the S5 interface towards the S-GW, the SGi interface towards the Internet, and the S7 interface towards the PCRF.
NextEPC provides the HSS (Home Subscriber Server) element of the EPC, i.e. the central database of mobile network subscribers, with their IMSI, MSISDN, cryptographic key materials, service subscription information, etc. It implements the S6a interface towards the MME using the DIAMETER protocol.
NextEPC contains the PCRF (Policy and Charging Rules Function), which controls the service quality (QoS) of individual connections and how to account/charge related traffic. It implements the Gx interface towards the PGW using the DIAMETER protocol.
The NextEPC service is registered in `systemd` environment, and is started automatically during the installation phase. The service names are *nextepc-mmed*, *nextepc-sgwd*, *nextepc-pgwd*, *nextepc-hssd*, and *nextepc-pcrfd*. You can use the `systemctl` command to control specific services.
```bash
sudo systemctl status nextepc-mmed (Check the service status)
sudo systemctl stop nextepc-mmed (Stop the service)
sudo systemctl disable nextepc-mmed (Will not be started after rebooting)
sudo systemctl enable nextepc-mmed (Will be started after rebooting)
sudo systemctl start nextepc-mmed (Start the service)
sudo systemctl restart nextepc-mmed (Stop and start)
Problem with NextEPC can be filed as [issues](https://github.com/acetcom/nextepc/issues) in this repository. And also, we've created *Discord* workspace for _nextepc_. Use [this link](https://discord.gg/GreNkuc) to get started.
Discussions related to this project are happening on the nextepc@lists.osmocom.org mailing list, please see <https://lists.osmocom.org/mailman/listinfo/nextepc> for subscription options and the list archive.
NextEPC source files are made available under the terms of the GNU Affero General Public License (GNU AGPLv3). See [this link](http://nextepc.org/docs/nextepc/4-license/) for details.