CostsUE connected but no internet access

[ikbalbtk]

Hello everyone,

I’m currently setting up a 5G SA network using srsRAN Project and Open5GS with a COTS UE. My UE successfully connects to the network, but I’m unable to access the internet. I suspect this might be linked to my configuration, particularly the AMF address.

Here’s my setup:

I’ve changed the AMF address to 10.53.0.2 instead of the 127.0.1.100 in the tutorial and plmn is 00101.
The UE connects to the network without any issues, but there’s no internet access.
So far, I’ve verified:

The APN is set to "srsapn" on both the UE and in the Open5GS configuration.
Despite this check, the UE still doesn’t have internet connectivity. I’d really appreciate your insights on:

Could using the AMF address to 10.53.0.2 and the plmn is 00101 be the reason for this issue?
What steps should I take to ensure the UE can access the internet with this configuration?
Thanks a lot for your help!

[pgawlowicz]

could you post gnb logs and ngap.pcap?

[ikbalbtk]

could you post gnb logs and ngap.pcap?

I am at your disposal for any further information.

[ikbalbtk]

end there's a screen for PduSessionRequest : ( the UE get the ip addr )

[JohnWilson614]

Have you tried setting up IPv4 forwarding?

sudo sysctl -w net.ipv4.ip_forward=1

sudo iptables -t nat -A POSTROUTING -s 10.45.0.0/16 ! -o ogstun -j MASQUERADE

[ikbalbtk]

Yes, I tried the given commands and even with the firewall disabled the problem persists.

[asheeshtripathi]

Try APN "internet" on both COTS UE and Core. We have tested with this APN and multiple COTS UEs successfully. Also, do not forget to run the following in your core machine:
Adding a route for the UE to have WAN connectivity
In order to bridge between the PGWU/UPF and WAN (Internet), you must enable IP forwarding and add a NAT rule to your IP Tables.

To enable forwarding and add the NAT rule, enter

Enable IPv4/IPv6 Forwarding

$ sudo sysctl -w net.ipv4.ip_forward=1
$ sudo sysctl -w net.ipv6.conf.all.forwarding=1

Add NAT Rule

$ sudo iptables -t nat -A POSTROUTING -s 10.45.0.0/16 ! -o ogstun -j MASQUERADE
$ sudo ip6tables -t nat -A POSTROUTING -s 2001:db8:cafe::/48 ! -o ogstun -j MASQUERADE
Configure the firewall correctly. Some operating systems (Ubuntu) by default enable firewall rules to block traffic.

$ sudo ufw status
Status: active
$ sudo ufw disable
Firewall stopped and disabled on system startup
$ sudo ufw status
Status: inactive
Optionally, you may consider the settings below for security purposes.

Ensure that the packets in the INPUT chain to the ogstun interface are accepted

$ sudo iptables -I INPUT -i ogstun -j ACCEPT