Solstice X.25 9.2 Developer's Guide

6.3.4 `qosformat`--Define OSI CONS QOS Parameters

OSI CONS-related quality-of-service parameters are defined in the quosformat structure:

#define MAX_PROT 32
 struct qosformat {
 	unsigned char reqtclass;
 	unsigned char locthroughput, remthroughput;
 	unsigned char reqminthruput;
 	unsigned char locminthru, remminthru;
 	unsigned char reqtransitdelay;
 	unsigned short transitdelay;
 	unsigned char reqmaxtransitdelay;
 	unsigned short acceptable;
 	unsigned char reqpriority;
 	unsigned char reqprtygain;
 	unsigned char reqprtykeep;
 	unsigned char prtydata;
 	unsigned char prtygain;
 	unsigned char prtykeep;
 	unsigned char reqlowprtydata;
 	unsigned char reqlowprtygain;
 	unsigned char reqlowprtykeep;
 	unsigned char lowprtydata;
 	unsigned char lowprtygain;
 	unsigned char lowprtykeep;
 	unsigned char protection_type;
 	unsigned char prot_len;
 	unsigned char lowprot_len;
 	unsigned char protection[MAX_PROT];
 	unsigned char lowprotection[MAX_PROT];
 	unsigned char reqexpedited;
 	unsigned char reqackservice;
 	struct extraformat xtras;
 };

The members of the qosformat structure are defined as follows:

Table 6-7 QOS Parameters


Member	Description
`reqtclass`	Indicates whether the throughput negotiation parameter is selected. 0 indicates that it is not selected.
`locthroughput`	Contains four-bit throughput encoding for local-to-remote calls.
`remthroughput`	Contains four-bit throughput encoding for remote-to-local calls.
`reqminthruput`	Indicates `whether` the minimum throughput negotiation parameter is selected.
`locminthru`	Contains four-bit throughput encoding for local to remote calls.
`remminthru`	Contains four-bit throughput encoding for remote to local calls.
`reqtransitdelay`	Indicates whether the transit delay parameter is selected. 0 indicates that it is not selected.
`transitdelay`	Contains the transit delay parameter as a 16-bit value. It is used in Call Requests and Indications and Confirms.
`reqmaxtransitdelay`	Indicates whether the calling NLI application specifies a maximum acceptable value for the transit delay parameter ("Lowest Quality Acceptable"). Note: The transit delay selection relates only to Call Requests and there is no transit delay QOS parameter in a Call Response primitive. The correct response when the indicated QOS is unattainable is to make a Clear Request. Also, in a Connect Confirm, the value of the selected transit delay will be placed in the `transitdelay` field when such negotiation takes place.
`acceptable`	Contains the maximum acceptable transit delay parameter, if this is specified by the calling NLI application.
`reqpriority`	Requests or indicates priority on a connection. 0 indicates that priority is not used.
`prtydata`	Contains the 8-bit value for the priority of data on the connection.
`reqprtygain`	Indicates that the field `prtygain` is used.
`reqprtykeep`	Indicates that the field `prtykeep` is used.
`prtygain`	Contains an 8-bit value for the priority to gain a connection.
`prtykeep`	Contains the 8-bit value priority to keep a connection.
`reqlowprtydata`	Indicates the field `lowprtydata` is used.
`reqlowprtygain`	Indicates the field `lowprtygain` is used.
`reqlowprtykeep`	Indicates the field `lowprtykeep` is used.
`lowprtydata`	Contains the lowest acceptable priority value. Used on `N-CONNECT` requests by the calling `NS_user`.
`lowprtygain`	Indicates the priority of data on a connection. Used on `N-CONNECT` requests by the calling `NS_user`.
`lowprtykeep`	Indicates priority for gaining a connection. Used on `N-CONNECT` requests by the calling `NS_user`.
`protection_type`	Indicates the type of protection required. Values are: `PRT_SRC` Source address specific `PRT_DST` Destination address specific `PRT_GLB` Globally unique 0 indicates that protection is not required. On `N-CONNECT` requests the calling `NS_user` may optionally specify a lowest acceptable level of protection.
`prot_len`	The length of the target protection.
`protection`	The value of target protection.
`lowprot_len`	The length of the lowest acceptable level of protection.
`lowprotection`	The lowest acceptable level of protection.
`reqexpedited`	Indicates whether expedited data is required/selected. For Connect Indications, a value of 1 implies that the expedited data negotiation facility was present in the Incoming Call packet, and that its use was requested. 0 indicates that expedited data is not used. Note: Negotiation is an OSI CONS procedure. When the facility is present and indicates non-use, use cannot be negotiated by Connect responses. See "6.4.3 `N_CI`--Call Request/Indication"and "6.4.2 `N_CC`--Call Response/Confirmation"for a description of the use of the `CONS_call` field in Call Requests and Call Responses. If the `CONS_call` flag is set to 0, Expedited Data Negotiation is not required--interrupt data is always available in X.25. This means that this field is ignored on Call Requests and Responses.
`reqackservice`	Indicates whether the acknowledgement service is to be used. Allowed values are: 0 indicates the service is not used. 1 signifies acknowledgment confirmation by the remote DTE. In the case of acknowledgment confirmation by the remote application, there is a one-to-one correspondence between D-bit data and acknowledgments with one data acknowledgment being received/sent for each D-bit data packet sent/received over the X.25 interface. 2 signifies acknowledgment confirmation by the remote application. In this case of acknowledgment confirmation by the remote DTE, no acknowledgments are expected or given over the X.25 interface. Any non-zero value causes negotiation in the call setup phase for use of the D-bit on the connection.

6.3.4 qosformat--Define OSI CONS QOS Parameters

6.3.4 `qosformat`--Define OSI CONS QOS Parameters