  The SPring-8 controls network has maintained accelerator operations in high
reliability and shown good performance during the past years. To cope with the
increase of loads on the network due to faster data acquisition and the
addition of equipment data, networking hardware has been installed in the last
few years. The upgraded network replaces the original FDDI backbone and
switches with mixed FDDI/gigabit ethernet and Layer-3 switches. It is necessary
to keep the double ring topology for the FDDI and introduce link aggregation
technology for the gigabit ethernet to maintain the full redundancy and
bandwidth of the system. This paper will discuss the network performance of the
gigabit ethernet including its latency and redundancy. We also discuss a future
plan for the network including Quality-of-Service over the gigabit ethernet.
