The reason this is something people want is that the UE in bridge mode can offer a public IP to a router behind the UE. I do agree that this is likely something very proprietary. A proxy-ARP would be good but I am not sure how that would work in the UE.
David Peterson Senior Engineer 855-947-7776 ext. 9214 c 419-706-7355 d 979-314-1305 https://www.ispsupplies.com
-----Original Message----- From: Harald Welte laforge@osmocom.org Sent: Tuesday, April 7, 2020 2:52 PM To: david@ispsupplies.com Cc: nextepc@lists.osmocom.org Subject: Re: Bridged APN
Hi David,
On Tue, Apr 07, 2020 at 06:18:23PM +0200, Harald Welte wrote:
On Mon, Apr 06, 2020 at 04:29:21PM -0400, david@ispsupplies.com wrote:
Does anyone have any experience with a bridged APN on Open5GS?
As far as I know, 3GPP didn't really introduce "Ethernet" type PDN contexts until very recent releases. For a long time, IPv4, IPv6 and IPv4v6 were the only available options.
I just checked: Etehernet type PDN connections are only supported in 5G, but not in 4G/EPC. Even Releae 15 doesn't mention it at all.
So whatever some vendors may be offering, I would bet it is not really any actual Ethernet bridging. It may be more something like proxy-ARP on the PGW side, but still only passing IP over the 4G network.
The big question is: What is it used for, and what are the requirements of that use case? A real Ethernet bridge would be transparent regarding the MAC addresses on both sides. And that's what I'm stating is not possible over 4G as per 3GPP specs.