  In the context of the upgrade of the Large Hadron Collider at CERN for
high-luminosity operation, the particle detectors have to cope with much higher
data rates and therefore need to upgrade their data acquisition systems. This
upgrade is taken as an opportunity to exchange the currently used highly
customized hardware by commercial solutions. Nevertheless, some part of the
data processing still needs to be done within Field Programmable Gate Arrays
(FPGA), requiring the transfer of data between the FPGAs and the commercial
servers. This paper reports on a study of direct data transmission from FPGAs
to servers via a commercial network. Large data buffers as required for
reliable data-transmission protocols are avoided by using an emerging technique
named eXpress Data Path (XDP). Based on XDP, the transmission of 5.2 PB (i.e.
2.92 * 10^{12} packets) was achieved within 168 h without a single missing
packet.

Networking and Internet Architecture