On Wed, Sep 20, 2017 at 5:04 PM, Harald Welte <lafo...@gnumonks.org> wrote: > Hi Tom, > > On Wed, Sep 20, 2017 at 01:40:54PM -0700, Tom Herbert wrote: >> On Wed, Sep 20, 2017 at 12:45 PM, David Miller <da...@davemloft.net> wrote: >> > There is a socket associated with the tunnel to do the encapsulation >> > and it has an address family, right? >> >> If fd's are set from userspace for the sockets then we could derive >> the address family from them. I'll change that. Although, looking at >> now I am wondering why were passing fds into GTP instead of just >> having the kernel create the UDP port like is done for other encaps. > > because the userspace process has to take care of those bits of GTP-U > that the kernel doesn't, such as responding to GTP ECHO requests with > GTP echo responses. Only the "GTP Message type G-PDU" is handled in the > kernel, as only those frames contain user plane. See table 1 of Section > 7.1 of 3GPP TS 29.060. > Okay, thanks for the explanation.
Tom
