Decapsulate GTP-U payload and forward to a Router

Matthew Evans mattevans123@REDACTED
Mon Jul 6 03:13:31 CEST 2020

Have you looked at the procket library? Lots of low-level socket manipulation tools..

Sent from my iPhone

On Jul 5, 2020, at 8:56 PM, Papa Tana <papa.tana101@REDACTED> wrote:

Hi All,

I am a node built in Erlang, and I receive lots of GTP-U packets:

---> GTP-U packets ---------> My Node as a Relay ----> Router [using
NAT]----> Internet

As shown above, the Erlang node task is to decapsulate the user data
(GTP-U Message Type is T-PDU (0xff)) and forward them to the Router,
without changing any information, just forward it, that's all.

I was used to send application message in binary as a Client, just
using gen_udp and gen_tcp, but now, I am not the Client. And not the
server because those messages are not for me neither.

=> Then, after I decapsulate these messages from GTP-U, I would like
to relay these layer messages to the Router with which I am connected.
The Router should connect with me with one network interface, using
the same netmask, let's say a small /30 netmask, it's obvious.

The IP addresses (src and dst) in the payload are not "from" me and
not "for" me.
Any tips please?

Thank you,
Best Regards,
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <>

More information about the erlang-questions mailing list