Port > Distance Extension
Use the Distance Extension subtab to set up distance extension parameters. For a list of ONS nodes and cards that support this subtab, see Provisioning.
 
Port
Displays the card port number.
Enable Distance Extension
If checked, allows additional distance by providing a GFP-T based flow control scheme. It enables the node to be a part of a SAN with long-distance, remote nodes. If left unchecked, the remaining options are not available for editing. If Distance Extension is enabled, set the connected Fibre Channel switches to Interop or Open Fabric mode, depending on the Fibre Channel switch. By default, the FC_MR-4 card will interoperate with the Cisco MDS storage products.
Auto Detect Credits
(Does not apply to all cards) If checked, enables the node to detect the transmit credits from a remote node. Credits are used for link flow control and for Extended Link Protocol (ELP) login frames between Fibre Channel/FICON Switch E ports.
Credits Available
(Does not apply to all cards) Sets the number of credits if an ELP login frame setting is missing or if the ELP login frame cannot be detected. Possible values are 2 through 256 in multiples of 2. Credits Available is editable only if Auto Detect Credits is unchecked.
Note
Longer distances between connected devices need more credits to compensate for the latency introduced by the long-distance link. The value should never be greater than the number of credits supported by the Fibre Channel/FICON port.
Autoadjust GFP Buffer Threshold
(Does not apply to all cards) If checked, guarantees the best utilization of the SONET/SDH transport in terms of bandwidth and latency.
GFP Buffers Available
(Does not apply to all cards) Sets the GFP buffer depth. Possible values are 16 through 1200 in multiples of 16. GFP Buffers Available is editable if Autoadjust GFP Buffer Threshold is unchecked. For shorter SDH transport distances, Cisco recommends lower values to decrease latency. For longer SDH transport distances, Cisco recommends higher values to provide higher bandwidth.
Apply
Applies changes made to the fields in the tab.
Reset
Cancels any changes to the tab and returns the fields to their last-saved settings.
Help
Displays context-sensitive help.

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