One the other hand, the cost of computing the checksum is tiny compared
to the cost of encrypting the packets. So there is a small performance
gain in not computing the checksum, compensate by the potential gain of
loosing compatibility.
If I were to do that, I would do some trials. Until the handshake is
complete, use the checksum. Then, send a trial packet with null
checksum. If the peer acknowledges it, then further packets can be sent
with null checksum. Redo the trial for each new path, or if there are
large number of packet losses. Basically, treat that the same way we do
PMTUD.
-- Christian Huitema
On 3/12/2024 3:57 PM, Martin Thomson wrote:
The question is more of a compatibility one than anything else. What, if
anything breaks if you do this?
As noted, there are contexts in which not computing the checksum works. So I
guess the conclusion is that nothing breaks, so go ahead. QUIC doesn't depend
on the checksum. All the cryptographic bits of QUIC use far stronger and more
reliable mechanisms.
On Tue, Mar 12, 2024, at 22:04, Shihang(Vincent) wrote:
Hi QUIC wg,
Since QUIC has strong encryption and integrity protection provided by
TLS 1.3. I wonder if the UDP checksum can be disabled(using UDP Zero
Checksum Mode https://www.rfc-editor.org/rfc/rfc6936 )to save the
computation just like in VXLAN(RFC7348
<https://datatracker.ietf.org/doc/html/rfc7348#autoid-12>).
Thanks,
Hang
