# Networking

Current measured bandwidth and here, too.

There are two high bandwidth networks in Daya Bay.

The first is the network that will connect Daya Bay to IHEP.

To calculate the network bandwidth from the Daya Bay site to the outside world we start with the Maximum theoretical DAQ rate of 500 GB/day.

A maximum DAQ rate of 500 GB/day is ~46 Mbps (we have lower projected data volumes, but will not under-provision DayaNet).

Assuming that we would want to double data transfer rates during periods of recovery (eg it would take 24 hours to recover from a 24 hour outage) doubles the data transfer bandwidth to 92 Mbps

Estimating the online control, video conferencing, email, web-browsing and incidental network usage is impossible, but we know that video conferencing with a DSL line is easy, so even predicting 10 Mbps is more than sufficient.

All networks try to run at ~30%-40% capacity for totally smooth package traffic with no/few collisions. Jason thinks that we can get at most 80% capacity if we tune the tcp buffers, use reasonable data transfer protocols, etc.

56 Mbps nominal bandwidth usage on a 155 Mbps OC3 is 36% occupancy. 102 Mbps recover bandwidth usage on a 155 Mbps OC3 is 66% occupancy.

The second network will be the one that connects IHEP to NERSC in the US.

This network will have to provide the same bandwidth as the network above plus all the processed data at IHEP.