Flow : DLC <------> NODE
| Field | Type | Description | 
|---|---|---|
| nxtqptr | PPTRBFHDR | Pointer to next buffer header in a queue | 
| hdreptr | PPTRBFELT | Pointer to first buffer element | 
| numelts | CCHAR | Number of buffer elements | 
| msgtype | CCHAR | Message type: DLCDATA (0x10) | 
| srcl | CCHAR | Source locality | 
| srcp | CCHAR | Source partner | 
| srci | INTEGER | Source index | 
| destl | CCHAR | Destination locality | 
| destp | CCHAR | Destination partner | 
| desti | INTEGER | Destination index | 
| ddhdr.ddth01 | CCHAR[6] | Transmission header | 
| Field | Type | Description | 
|---|---|---|
| hdreptr–>elteptr | PPTRBFELT | Pointer to next buffer element: (NULL is only one element) | 
| hdreptr–>startd | INTEGER | Index to start of data in this buffer element's data array: 1 | 
| hdreptr–>endd | INTEGER | Index to last byte of data in this buffer element's data array | 
| hdreptr–>dataru | CHAR[SNANBEDA] | Defined as follows, where s = startd–1 | 
| dataru[s..s+n–1] | SNA request header (RH) if present, and request unit (RU) |