| ## Configuring DTS for WANs and WAN Links Because there are many variations of WAN configurations, especially in combination with LANs and extended LANs, it is impossible to describe every case where a WAN link can be used to disseminate time. This topic does not give recommendations for every case involving a WAN link, but it describes how you can set up your DTS implementation by using several generic configurations as examples. Due to the variable delay inherent in any WAN link, it is difficult to maintain a consistent skew between clocks on opposite sides of the link. DTS synchronizes clocks across WAN interfaces, but larger inaccuracies occur between the clocks to account for the worst case transmission delay during each synchronization. A reliable and robust DTS installation is important any time WAN links are part of a cell. Because WANs are less reliable than LANs, plan for some redundancy in any DTS installation that involves WAN links. Try to place servers so that there will always be three or more available, even if one of the WAN links goes down. The following subtopics give recommendations for three basic WAN configurations: · A LAN or extended LAN with WAN links to remote nodes · LANs that are connected by WAN links · An all-WAN cell with a central host or cluster Your cell may not exactly match any of the configurations, but you can plan your cell by following the recommendations for each example. More: LANs with WAN Links to Remote Sites LANs Connected by WAN Links WAN Cells ###