Description:

RFC 938:

IRTP is a full duplex, transaction oriented, host to host protocol which provides reliable sequenced delivery of packets of data, called transaction packets.

IRTP header:

Type. 8 bits.

Port. 8 bits.
(RFC 938) This field is used for the multiplexing and demultiplexing of packets from multiple user processes across a single IRTP connection. Processes which desire to use IRTP must claim port numbers. A port number represents a higher level protocol, and data to/from this port may be exchanged only with a process which has claimed the same port number at a remote host. A process can claim multiple port numbers, however, only one process may claim an individual port number. All port numbers are well-known.

Sequence number. 16 bits.
(RFC 938) For each communicating pair of hosts, there are two sequence numbers defined, which are the send sequence numbers for the two ends. Sequence numbers are treated as unsigned 16 bit integers. Each time a new transaction packet is sent, the sender increases the sequence number by one. Initial sequence numbers are established when the connection is resynchronized.

Checksum. 16 bits.
The 16-bit one's complement of the one's complement sum of the IRTP header and the transaction packet data.

Data. Variable length.

Glossary:

RFCs:

[RFC 938] Internet Reliable Transaction Protocol Functional and Interface Specification.