What's NextEPC

NextEPC is a C-language Open Source implementation of the 3GPP Evolved Packet Core, i.e. the core network of an LTE network.

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.

Installation

This post will guide you on how to get installed NextEPC with your environment. To date, NextEPC has been tested on GNU/Linux distributions(Debian, Ubuntu, CentOS, Fedora, OpenSUSE), FreeBSD, and Mac OS X.

Ubuntu

To get the latest Ubuntu version, please visit the official Ubuntu website: https://www.ubuntu.com/download/.

• Install with a Package Manager

The Nextepc package is available on the recent versions of Ubuntu.

sudo add-apt-repository ppa:acetcom/nextepc
sudo apt-get update
sudo apt-get install nextepc

This will create a virtual network interface named as pgwtun. It is automatically removed by uninstalling NextEPC.

ifconfig pgwtun
pgwtun    Link encap:UNSPEC  HWaddr 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00  
          inet addr:45.45.0.1  P-t-P:45.45.0.1  Mask:255.255.0.0
          inet6 addr: fe80::50f6:182c:5aa3:16bb/64 Scope:Link
          inet6 addr: cafe::1/64 Scope:Global
          ...

• Uninstall NextEPC

sudo apt-get purge nextepc-core

You may need to remove manually /var/log/nextepc unless it is empty.

sudo rm -Rf /var/log/nextepc

Debian, CentOS, Fedora, OpenSUSE, FreeBSD, and Mac OS X

For these OS, you should build NextEPC from the code. First clone this repository and then follow instructions described in the documentation.

• FreeBSD

• Mac OS X

• CentOS

• Fedora

• Ubuntu

Configuraiton

In LTE, there are tons of configurable parameters. This page will guide you to set essential parameters up. The configuration consists of two parts: IP network connectivity and LTE network settings.

1. IP Connectivity between Network Entities

The minimum requirement of having IP connectvity is to add a route for UE to have Internet connectivity.

By default, a LTE UE will receive a IP address with the network address of 45.45.0.0/16 or cafe::0/64. If you have a NAT router (e.g., wireless router, cable modem, etc), the LTE UE can reach Internet in uplink, but it cannot in downlink. It's because the NAT router has no idea on these IP addresses, so adding a route is required. Please refer to the user manual to know how to add a static route in your router.

Add a route of both 45.45.0.0/16 and cafe::0/64 to go the PGW IP address. For example, a command for Linux will be:

sudo ip route add 45.45.0.0/16 via <PGW IP address>
sudo ip route add cafe::0/64 via <PGW IP address>

2. LTE Network Settings

By default, LTE PLMN and TAC are set as shown in the following:

mme:
    gummei: 
      plmn_id:
        mcc: 001
        mnc: 01
      mme_gid: 2
      mme_code: 1
    tai:
      plmn_id:
        mcc: 001
        mnc: 01
      tac: 12345

The LTE EnodeBs need to be set to use the same values of PLMN and TAC in NextEPC. If you want to change them, please modifiy in /etc/nextepc/mme.conf.

After changing conf files, please restart NextEPC daemons.

systemctl restart nextepc-mmed

Web UI

NextEPC has a number of configuration files corresponding to LTE network entities, which are in YAML format. The LTE user subcription information of NextEPC is stored and maintained by Mongo DB. Configuration files, located in etc/nextepc/*.conf can be easily modified using a general text editor such as vi or emacs, while managing the subscriber information requires a Mongo DB client.

NextEPC provides an alternative management interface for customers to manage their subscriber information in an easy way, that is Web User Interface. The following shows how to install the Web UI of NextEPC.

1. Install Node.js and NPM

To get the latest Node.js and NPM, please visit the official Node.js website: https://nodesjs.org/en/download/.

Or, you can install Node.js and NPM if you're using Ubuntu:

sudo apt-get -y install curl gnupg
curl -sL https://deb.nodesource.com/setup_8.x | sudo -E bash -
sudo apt-get -y install nodejs

2. Obtain the source code

git clone https://github.com/acetcom/nextepc

3. Install the dependencies to build the code

cd nextepc/webui
npm install

4. Build

npm run build

5. Running

npm run start

Now the web server is running on http://localhost:3000.

6. Login with the default account

Open http://localhost:3000. Login with admin.

• Username : admin
• Password : 1423

Please change the password in Account Menu.

7. Register a subscriber

Using Web UI, you can add a subscriber without a Mongo DB client.

• Go to Subscriber Menu.
• Click + Button to add a new subscriber.
• Fill the IMSI, security context(K, OPc, AMF), and APN of the subscriber.
• Click SAVE Button

This addition affects immediately NextEPC without restaring any daemon.