Hi Osmocom team.
We are sorry to disturb you.
We have a question about establishing a stable internet connection (IuPS_PS) between MS and our developed network core system using our home nodeB (HNB).
We set Primary DNS Address: 172.60.3.154 (core IP) and Secondary DNS Address: 8.8.8.8 in Activate PDP Context Accept.
At this step, we can see the MS packets in the interface between HNB and core using wireshark. The protocol is GTP <DNS> and the stacked layers are DNS / UDP / IP / GTP / UDP / IP which I attached a screenshot of the wireshark log.
As you can see in the attached image, our query in the MS is server.hnb (http://server.hnb). In order to show our default page to the user query, we set up a DNS server and HTTP server (Apache) in 172.60.3.154 and BIND9 is configured as the primary server for the domain server.hnb. The command dig @localhost server.hnb outputs the following:

; <<>> DiG 9.16.1-Ubuntu <<>> @localhost server.hnb
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 49532
;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
; COOKIE: 15821f64047895870100000060070fb921a17af91fd22f9f (good)
;; QUESTION SECTION:
;server.hnb. IN A

;; ANSWER SECTION:
server.hnb. 604800 IN A 172.60.3.154

;; Query time: 0 msec
;; SERVER: 127.0.0.1#53(127.0.0.1)
;; WHEN: Jan 19 20:28:33 +0330 2021
;; MSG SIZE  rcvd: 83

and also when we query http://server.hnb in the browser of the core system (172.60.3.154), we see the Apache2 Ubuntu Default Page but this default page is not shown in the MS.
Furthermore, we think that a GTP tunnel may be required and we set up a GTP tunnel using libgtpnl and the two following commands:

gtp-link add gtp1
gtp-tunnel add gtp1 v1 1 100 10.250.0.114 172.60.3.154

where 1 is the gTP-TEI obtained in RAB-Assignment Response and 100 is the similar field in RAB-Assignment Request. Also, 10.250.0.114 is the MS IP and 172.60.3.154 is the core IP. But there is no captured package in this tunnel (using wireshark).

Could you please help us to solve this problem which is mentioned in the following questions?
Is the above procedure performed in the correct way?
We want to show our default page in MS when the user query is http://server.hnb, but we think that a GTP manager is required to split the (( DNS / UDP / IP )) layers from (( DNS / UDP / IP / GTP / UDP / IP )) to send to DNS server. How can it be solved, if this assumption is correct?

Thank you again for spending time with us.
Best regards,
Morteza Ali Ahmadi


--
When there is much light, The shadow is deep...