OSF DCE Administration Guide--Core Components

Planning Your DTS Implementation

• If you are using a single time-provider, locate it at one of the global servers on the

LAN, rather than at a remote server.

The network conﬁguration that results from the preceding rules concentrates the servers

on the LAN, so clock skews are kept to a minimum and the service is not dependent on

remote nodes that may be physically inaccessible to the system manager. Each remote

clerk node synchronizes with the global servers to satisfy the minservers attribute

setting.

24.5.2 LANsConnected by WAN Links

The rules outlined for extended LANs that use bridges also apply to LANs that are

connected by WAN links. Each LAN in such a network is a separate entity, so several

DTS servers must be conﬁgured on all of the LANs. Conﬁgure each LAN according to

the following guidelines:

• Conﬁgure at least three DTS servers on each LAN.

• Conﬁgure at least one server on each LAN as a courier.

• Conﬁgure at least one global server on each LAN.

• If you are using time-providers, install them at the global servers.

These recommendations lead to higher DTS efﬁciency and availability despite the

irregular delays that are associated with WAN links.

24.5.3 WAN Cells

Figure 24-3 shows a geographically distributed cell that does not have any LANs. DTS

delivers higher clock skews in an all-WAN environment than in an all-LAN

environment, but it still provides synchronization that is adequate for most distributed

applications. In such a network, clock skews are typically less than 5 seconds, but they

may be as much as 30 seconds if satellite links are used.

Figure 24-3. DTS Conﬁguration—WAN Networks

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