On Wed, 18 Oct 2023 10:53:02 +0900 takeru hayasaka wrote:
For instance, there are PGWs that have the capability
to separate the
termination of communication of 4G LTE users into Control and User
planes (C/U).
This is quite convenient from a scalability perspective. In fact, in
5G UPF, the communication is explicitly only on the User plane
(Uplane).
Therefore, services are expected to receive only GTPU traffic (e.g.,
PGW-U, UPF) or only GTPC traffic (e.g., PGW-C). Hence, there arises a
necessity to use only GTPU.
If we do not distinguish packets into Control/User (C/U) with options
like gtp4|6, I can conceive scenarios where performance tuning becomes
challenging.
For example, in cases where we want to process only the control
communication (GTPC) using Flow Director on specific CPUs, while
processing GTPU on the remaining cores.
In scenarios like IoT, where user communication is minimal but the
volume of devices is vast, the control traffic could substantially
increase. Thus, this might also be possible in reverse.
In short, this pertains to being mindful of CPU core affinity.
If we were to propose again, setting aside considerations specific to
Intel, I believe, considering the users of ethtool, the smallest units
should be gtpu4|6 and gtpc4|6.
Regarding Extension Headers and such, I think it would be more
straightforward to handle them implicitly.
What does everyone else think?
Harald went further and questioned use of the same IP addresses for
-U and -C traffic, but even within one endpoint aren't these running
on a different port? Can someone reasonably use the same UDP port
for both types of traffic?