lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  PHC 
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:   Sat, 12 Dec 2020 11:07:05 +0100
From:   Harald Welte <>
To:     Jonas Bonn <>
Subject: Re: [PATCH net-next v2 07/12] gtp: use ephemeral source port

Hi Jonas,

On Fri, Dec 11, 2020 at 01:26:07PM +0100, Jonas Bonn wrote:
> From 3GPP TS 29.281:
> "...the UDP Source Port or the Flow Label field... should be set dynamically
> by the sending GTP-U entity to help balancing the load in the transport
> network."

You unfortuantely didn't specifiy which 3GPP release you are referring to.

At least in V15.7.0 (2020-01)  Release 15 I can only find:

"For the messages described below, the UDP Source Port (except as
specified for the Echo Response message) may be allocated either
statically or dynamically by the sending GTP-U entity.  NOTE: Dynamic
allocation of the UDP source port can help balancing the load in the
network, depending on network deployments and network node

For GTPv0, TS 29.060 states:

"The UDP Source Port is a locally allocated port number at the sending

unfortuantely it doesn't say if it's a locally allocated number globally
for that entire GSN/RNC, or it's dynamic per flow or per packet.

As I'm aware of a lot of very tight packet filtering between GSNs,
I would probably not go for fully dynamic source port allocation
without some kind of way how the user (GTP-control instance) being
able to decide on that policy.

- Harald Welte <> 
"Privacy in residential applications is a desirable marketing option."
                                                  (ETSI EN 300 175-7 Ch. A6)

Powered by blists - more mailing lists