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Appendix C

Common Management
Structures and Parameters

Field	Description
`id`	Value identifying structure as a TX API handle.
`cpihndl`	Handle returned from CPI Library. Use this value to access CPI Library directly.
`cp`	TX board communications processor number associated with handle. Used as test communications processor for TxApiPktInit. May be set by application if TxApiOpen is called with cp `= 0`.
`rmt_cp`	CP number of remote TX board communications processor when managing remote node (UDP access from local communications processor).
`rmt_node`	IP address of remote TX board communications processor when managing remote node.

Field	Description
`dprhdr`	Dual port RAM header: source and destination communications processor number's (0 = host) and DPR packet size.
`rproto`	Reserved for future use.
`srcaddr`	Source address used for remote node management (all zeroes = host system).
`dstaddr`	Remote destination address: remote TX board communications processor number and IP address.
`iopkt`	Image of IO packet to be issued on communications processor on behalf of application. See `cpkuser.h` for a complete description.
`notif`	Field available for notification processing.
`key`	General purpose key used by NETMGR task on communications processor.
`flags`	General control flags: indication of request (IO request) or response (`IODONE`)
`datablk`	Area for holding all other data associated with IO request/response. Holds destination entity name and all other passed structures.

The common portion of the TX Common Management API does not use this structure. It is provided in txapi.h so that it is available to all TX management extension APIs (TPX, Ds0 Over IP, and X.25 API).
The method for APIs returning lists of items in response to a show summary request is to return as many instances of the requested structure as are able to fit in the provided response buffer. Tasks return a count of the number of items returned as well as the next index to use to obtain more entries. The Show Summary Control structure is provided to assist applications in extracting this information. Field Description summrec Pointer to next summary record. nxtindex Index value to pass to TxxxxShSumm function to obtain next set of responses. repeatflag Determines whether it is time to repeat the send of the actual show summary request to the communications processor.

Field	Description
`summrec`	Pointer to next summary record.
`nxtindex`	Index value to pass to TxxxxShSumm function to obtain next set of responses.
`repeatflag`	Determines whether it is time to repeat the send of the actual show summary request to the communications processor.

The following structures are used to pass information between the application and the TPX API.

There are several commands to the TPX task which require the specification of an IP address. Certain of these commands also require a subnet mask / broadcast address.
The structure TXTPXIPADDR is defined by the TPX API to allow this information to be specified. Each time the structure is used by an API function, the documentation lists which of the IP address structure sub-fields are used.
Whenever subnet mask is expected, the application may specify a mask of all zeroes to indicate that the API should select the mask identified by the class of the IP address. The following choices apply: Mask IP Address Class <127 or less>.*.*.* Class A address (mask = 255.0.0.0) <128-191>.*.*.* Class B address (mask = 255.255.0.0) <192 or higher>.*.*.* Class C address (mask = 255.255.255.0)
Whenever a broadcast mask is expected, the application may specify all 0's to indicate that the API should select the broadcast address based on the IP address and subnet mask portions of the IP address. In this case, the API generates the broadcast address by combining the IP address masked off to the subnet mask significant bits with all bits set beyond the subnet mask bits. For example, IP address 1.2.3.4 with subnet mask 255.255.255.0 defines in a broadcast address of 1.2.3.255.

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