Hi Lynxis,

Thank you for your response and suggestions. Regarding my current network setup, I am using a b200 device to connect my Android phone to the osmobts network. I am able to establish roaming connections successfully, and I can make and receive calls as well as send and receive SMS.
However, I am encountering an issue with the network connection for data services. I am not able to connect to the E (EDGE) or G (GPRS) networks. Despite being in a coverage area, my phone does not receive an IP address for data services. It seems that the GPRS/EDGE setup is not functioning properly.
I have checked the configuration files and made the necessary adjustments based on your recommendations. I have also reviewed the tun.network file and corrected the device name to "tun4". However, I am still experiencing difficulties.

To provide more information, here are some specific questions:

Can my mobile phone successfully connect to the network for voice calls and SMS?
Yes, I can make and receive voice calls and send/receive SMS without any issues.
Is the Circuit-Switched (CS) functionality, such as location update, working properly?
Yes, the CS functionality, including location update, is working as expected.
Is the Packet-Switched (PS) functionality, such as routing area update, working properly?
No, the PS functionality, including routing area update, is not working. I am unable to establish a network connection for data services.
Is my phone receiving an IP address for data services (PDP Context)?
No, my phone is not receiving an IP address for data services.
Have I checked for network traffic using tcpdump -i tun4 -vn?
Yes, I have checked for network traffic using the mentioned command, and I have got this:
tcpdump: listening on tun4, link-type EN10MB (Ethernet), snapshot length 262144 bytes

Unfortunately, I do not have a pcap trace available at the moment. If necessary, I can provide additional information or logs to assist with troubleshooting.
Thank you for your continued support.

Log:

Best regards,
Tahmid

On Sat, 20 May 2023 at 16:42, Alexander 'lynxis' Couzens <lynxis@fe80.eu> wrote:

Hi Ahnaf,

the structure of osmocom have changed since the manual has been written.
The manual is written for the long outdated osmo-nitb (a combined BSC,MSC).

> I have noticed that the wiki page for OpenBSC GPRS at
> https://osmocom.org/projects/cellular-infrastructure/wiki/OpenBSC_GPRS has
> not been updated for four years, and since then, there have been
> significant updates to the software. As a result, the information on the
> GPRS/EDGE Setup page may be outdated, and I am struggling to configure GPRS
> on my system.
>
> I have attached my configuration files below for your review.

I would recommend to take a look into the https://osmocom.org/projects/cellular-infrastructure/wiki/Osmocom_Network_In_The_Box
But you already have configuration files for bsc, msc, sgsn, ggsn.

I would also recommend you to add an IP for every core network component and ran.
Because it helps debugging to have the IPs seperate.
For a local network (everything runs on the same host) I would do:

* 127.0.0.10 bts + pcu
* 127.0.0.11 bsc + bsc-mgw (yes running mgw twice)j
* 127.0.0.12 msc + osmo-sip-connector + msc-mgw
* 127.0.0.13 sgsn
* 127.0.0.14 ggsn
* 127.0.0.15 sip-server (e.g. asterix, ...)
* 127.0.0.16 hlr
You will need to change vty and ctrl interface ips as well.

Back to your current network.
Are you running osmo-stp? osmo-stp is required for the new network.

Ok. but what is not working? Please add more information!

- Can your MS/UE connect to the network?
- CS: location update works?
- PS: routing area update works?
- Does your phones gets an IP? (PDP Context)
- Does `tcpdump -i tun4 -vn` shows any traffic?

Do you have a pcap trace? (Best to upload it to a website and only send the link on this mailinglist)

Your tun.network file looks wrong. The device should be named tun4 and the IP range is also wrong.
Personally I wouldn't use systemd-networkd for this.
At least I would expect routing issues. Also I wonder why there isn't a tun4 device.

Even if there is a tun4 device, you might missing the routing and depending on your setup, NAT/masquerading.
I think you would need to run `ip route add 172.16.222.0/24 dev tun4`
and `iptables -t nat -A POSTROUTING -j MASQUERADE -s 172.16.222.0/24 -o wlp1s0`

Best,
lynxis