Stephen McQuistin and Colin Perkins
Proceedings of the ACM Internet Measurement Conference,
Tokyo, Japan,
October 2015.
DOI:10.1145/2815675.2815716
We present initial measurements to determine if ECN is usable with UDP
traffic in the public Internet. This is interesting because ECN is part
of current IETF proposals for congestion control of UDP- based
interactive multimedia, and due to the increasing use of UDP as a
substrate on which new transport protocols can be deployed. Using
measurements from the author’s homes, their workplace, and cloud
servers in each of the nine EC2 regions worldwide, we test reachability
of 2500 servers from the public NTP server pool, using ECT(0) and
not-ECT marked UDP packets. We show that an average of 98.97% of the
NTP servers that are reachable using not-ECT marked packets are also
reachable using ECT(0) marked UDP packets, and that 98% of network
hops pass ECT(0) marked packets without clearing the ECT bits. We
compare reachability of the same hosts using ECN with TCP, finding that
82.0% of those reachable with TCP can successfully negotiate and use
ECN. Our findings suggest that ECN is broadly usable with UDP traffic,
and that support for use of ECN with TCP has increased.
Download: mcquistin2015ecn-udp.pdf