# SGSN - Serving GPRS Support Node

```
sudo vi  /etc/osmocom/osmo-sgsn.cfg
```

```
!
! Osmocom SGSN configuration
!
!
line vty
 no login
!
sgsn
 gtp local-ip 127.0.0.1
 ggsn 0 remote-ip 127.0.0.6
 ggsn 0 gtp-version 1
! auth-policy closed
! accept-all, closed, acl-only, remote
 auth-policy accept-all
ns
 timer tns-block 3
 timer tns-block-retries 3
 timer tns-reset 3
 timer tns-reset-retries 3
 timer tns-test 30
 timer tns-alive 3
 timer tns-alive-retries 10
 encapsulation udp local-ip 127.0.0.1
 encapsulation udp local-port 23000
 encapsulation framerelay-gre enabled 0
!
bssgp
!

```


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://gsm-hacking.telco-sec.com/2g-in-a-b0x/sgsn-serving-gprs-support-node.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.