TS Supplement (Includes RFC-1006 Support)

DT-TPDU

TPDUs Used by RFC-1006

107751 Tandem Computers Incorporated 5–11

DT-TPDU The Data Transfer (DT) TPDU is unchanged when using RFC-1006. Figure 5-7

illustrates the DT-TPDU.

Figure 5-7. DT-TPDU

Octet

1 2 3 4 to end

DT TPDU-NR EOT

User Data

TPDU Header

070

The length indicator shows the TPDU header length in octets. This value does not

include the length of LI and User Data and has the value of 2.

The data transfer code is 1111 0000. This value is in octet 2.

EOT

When set to 1, the end-of-text field indicates that the current DT-TPDU is the last

data unit of a complete DT-TPDU sequence (or the end of the TSDU). This value is

in bit 8 of octet 3 (the high-order bit, bit mask 1000 0000).

TPDU-NR

Is the TPDU send sequence number, and has the value of 0.

User data

Contains the data of the TSDU being transmitted. The length of this field is

limited to the negotiated TPDU size for the transport connection (minus the 3

octets of the TPDU header).