OSF DCE Administration Guide--Core Components

OSF DCE Administration Guide—Core Components
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 subsections 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.
24.5.1 LANswith WAN Links to Remote Sites
Figure 24-2 shows a LAN that incorporates several remote nodes by using WAN links.
Figure 24-2. DTS Configuration—LAN with WAN Links
ClerkServer
Clerk
Global/
Courier
Server
Global/
Courier
Server
Clerk
ClerkClerk
Modem
Modem Modem
Modem
(Time−Provider)
TP
ServerServer Clerk
Clerk
In this configuration, follow the basic recommendations for a single LAN, but also
adhere to these rules:
• Configure servers at remote sites as global and courier servers.
• The LAN should have a minimum of three servers.
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