Please note that nextepc.conf is used only if NextEPC is executed through nextepc-epcd. Otherwise, mme.conf, sgw.conf, pgw.conf, hss.conf, and pcrf.conf should be modifed for the configuration.
IP Connectivity between Network Entities
The minimum requirement of having IP connectvity is to modify the configuration files of MME and SGW.
Modification of MME configIn
/etc/nextepc/mme.conf, go to mme → s1ap. Please set your IP address after
mme: freeDiameter: mme.conf s1ap: addr: <IP address> ...
Modification of SGW configIn
/etc/nextepc/sgw.conf, go to sgw → gtpu. Please set your IP address after
sgw: gtpc: addr: 127.0.0.2 gtpu: addr: <IP address> ...
Internet Access for UEs
First, please make sure that ip_forwarding = 1:
sysctl net.ipv4.ip_forward net.ipv4.ip_forward = 0 sudo sh -c "echo 1 > /proc/sys/net/ipv4/ip_forward"
Second, either method A or B is required for UEs to have Internet connectivity.
A. Adding a route on the gateway routerBy default, a LTE UE will receive a IP address with the network address of 22.214.171.124/16. 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 126.96.36.199/16, so adding a route is required. The following example shows adding two routes for 188.8.131.52/16 and cafe::0/64 in Linux:
sudo ip route add 184.108.40.206/16 via <'PGW IP address'> sudo ip route add cafe::0/64 via <'PGW IP address'>
B. NAT on PGWNAT can be done on NextEPC's PGW. You execute the following command in PGW installed host. Please check your outgoing network interface name (e.g
sudo iptables -t nat -A POSTROUTING -o <'interface-name'> -j MASQUERADE sudo iptables -I INPUT -i pgwtun -j ACCEPT
Network address settings
* MME S1AP: listen on all address avaiable in system GTP-C: listen on the first IP address in system DIAMETER: 127.0.0.2 (No TLS) * SGW GTP-C: 127.0.0.2 GTP-U: listen on the first IP address in system * PGW GTP-C: Both 127.0.0.3 and [::1] GTP-U: Both 127.0.0.3 and [::1] DIAMETER: 127.0.0.3 (No TLS) * HSS DIAMETER: 127.0.0.4 (No TLS) * PCRF DIAMETER: 127.0.0.5 (No TLS)
UE IP addressing
* IPv4 : 220.127.116.11/16 * IPv6 : cafe::1/64
* IPv4 Primary : 18.104.22.168 Secondary : 22.214.171.124 * IPv6 Primary : 2001:4860:4860::8888 Secondary : 2001:4860:4860::8844