Configuring a Packet Time-to-Live

The packet time-to-live is the number of hops that session data packets can take before expiring. The default is 2. This allows for a hub and an interface card, and prevents the data packets from leaving the local network. If sessions are hosted on different local area networks (LANs) that are part of wide area network (WAN), or if a firewall configuration prevents it, the announcement sent by one session may not reach the other sessions in the coordinated cache. In this case, consult your network administrator for the correct time-to-live value.

Table 88-13 summarizes which coordinated caches support packet time-to-live configuration.

Table 88-13 Coordinated Cache Support for Packet Time-to-Live Configuration

Coordinated Cache	Using TopLink Workbench	Using Java
JMS Coordinated Cache
RMI Coordinated Cache
CORBA Coordinated Cache
Custom Coordinated Cache

In addition to configuring packet time-to-live, you may also need to configure announcement delay (see "Configuring an Announcement Delay").

Using TopLink Workbench

To specify the number of hops that session data packets can take before expiring, use this procedure:

Select a session or session broker in the Navigator. Its properties appear in the Editor.
Ensure the Enable Cache Coordination option is selected, then select the appropriate coordinated cache Type (see Table 88-12). The cache coordination options appear on the tab.

Figure 88-10 Cache Coordination Tab, Packet Time to Live Field

Description of "Figure 88-10 Cache Coordination Tab, Packet Time to Live Field"

In the Packet Time to Live field, specify the number of hops (default = 2) that session data packets can take before expiring.