ZCOM Tables and Data Structures
Interface Table
The list headers in this array function identically to ITXLSTA only for the low priority transmit requests. A terminal may be linked to ITXLSTX, ITXLSTA and ITXLSTB all at the same time, if it has express, high, and low priority transmit requests in progress.
IPLIMIT - Port unacknowledged transmit limit (in bytes)
This array contains the limit (in bytes) of all unacknowledged transmit messages to terminals belonging to the same port or subchannel of this interface. This array contains one element, one for each port or subchannel of the Mux card. If the DAM issues a transmit request to the Mux card and the Mux card does not have enough free buffers to hold the request data, the Mux will reject the request with an “out of buffers” error. The DAM will retry the request after an unacknowledged transmit request completes. This field is used to minimize the number of retries (and thereby increase overall performance) by imposing a limit on the size of unacknowledged transmit requests. This array is initialized by TTGEN from the default value hpiplim in the ZCOM header. This value is configured through the
IPBYTES - Port unack TX size (in bytes)
This array is maintained by the DAM and keeps track of the number of
IPENDG_BUFS - Total pending transmit size (in # of buffers)
This field is used internally by the ZCOM drivers.
IPSTAT - Port/Subchannel status
Depending on the card type this interface table is for, this ipstat field either contains the status of each subchannel in a
The individual ipstat bits are handled as follows:
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