IP-DLC Connection and DLUR Retry Limits

When you create a “Host system” connection that uses the IP-DLC link service to connect to an IBM mainframe, the connection properties in SNA Manager include an IP DLC tab. The IP DLC tab is where you can configure Connection and DLUR retry limits for the connection. The following is a screen shot of the IP DLC property page:

Note The options on the IP DLC property page are disabled if the connection using the IP-DLC link service is configured with Remote end set to “Peer system”. This is because these settings are only applicable when communicating with a Dependent LU Server (DLUS) to access dependent LUs (e.g. 3270 LUs).

There have been a couple of questions around what the difference is between the Connection retry limits and the DLUR retry limits since there isn't much verbiage around these settings. As explained below, the difference is that one set of options is used when activating the connection and the other set of options are used when trying to recover from an active connection that has failed.

Connection retry limits: These settings are used for setting the retry limits when initially activating the connection to the DLUS. In this case, the DLUR (Dependent LU Requester) is the IP-DLC link service.

Unlimited: The IP-DLC link service will continue trying to activate the connection until it is successful.

Limited: Specifies the number of retries. Valid values are from 1 to 65534.

Delay after retry: Used to specify the wait period between retry attempts.

Note The value of this field can only be configured in 5 second increments with the default value being 10 seconds. This is because the value is saved in the HIS configuration in 5 seconds units. If you enter of 65535 or less (as long as it is a multiple of 5), the value entered will be used. If the value is not a multiple of 5, a dialog will be displayed indicating that the value is not a multiple of 5 and that it has been rounded when you try to save the changes. If you enter a value larger than 65535, the value will be changed to an unexpected value. For example: If a value of 70000 is manually entered, a value of 4464 will be displayed when clicking the Apply button.

DLUR retry limits: These settings are used to specify the retry limits in the event that the connection to the DLUS fails.

No retries: No retry attempts are made.

Unlimited: The IP-DLC link service will continue trying to activate the connection until it is successful.

Limited: Specifies the number of retries. Valid values are from 1 to 65534.

Delay after retry: Used to specify the wait period between retry attempts. Valid values are from 1 – 65535.