dns
The server's dns is used in combination with a name value to find a server from a seismogram DC. The names "IRIS_BudDataCenter", "IRIS_PondDataCenter", and "IRIS_ArchiveDataCenter" must be used in combination with the "edu/iris/dmc" dns value. The name "NCEDC_DataCenter" must be used in conjunction with the "edu/berkley/geo/quake" dns value. The name "SCEPPSeismogramDC" must be used in conjunction with a DNS value "edu/sc/seis".
Example
<dns>edu/iris/dmc</dns>
Places this can be found
fixedDataCenter
fixedDataCenter contains this directly