This document provides a framework for specifying future DPDUs. This document is part of the STANAG 5066 Extension Protocol (S5066-EP) series. The complete set of documents in this series are:

  1. STANAG 5066 Extension Protocol Index (S5066-EP1)
  2. STANAG 5066 Padding DPDU (S5066-EP2)
  3. Pipelining the CAS 1 Linking Protocol (S5066-EP3)
  4. Data Rate Selection in STANAG 5066 for Autobaud Waveforms (S5066-EP4)
  5. STANAG 5066 Large Windows Support (S5066-EP5)
  6. Slotted Option for STANAG 5066 Annex K (S5066-EP6)
  7. Advertising Extended Capabilities (S5066-EP7)
  8. Block Based EOTs (S5066-EP8)
  9. Compact Acknowledgement (S5066-EP9)
  10. Extension DPDU (S5066-EP10)
  11. Variable C_PDU Segment Size (S5066-EP11)
  12. HF Wireless Token Ring Protocol (S5066-EP12)
  13. STANAG 5066 Routing Sublayer (S5066-EP13)
  14. STANAG 5066 TRANSEC Crypto Layer using AES and other Protocols (S5066-EP14)
  15. AES Key Distribution for TRANSEC and Half Loop (S5066-EP15)

1. Motivation

STANAG 5066 left six spare DPDU type values for future protocol extension. Four of these have been used by S5066-EP5 and a fifth by S5066-EP2. This specification uses the last spare value to define an extension mechanism so that further DPDUs may be added in future extension specifications

2. Extension DPDU

6 5 4 3 2 1 LSB
0 DPDU Type = 13 EOW Type
3 Size of Address Field (m) Size of header (h)
3+m Source and Destination Address
4+m* MSB Extended DPDU Type LSB
  Optional Header Bytes that may be specified in Extended DPDU
CRC CRC on Header
h+m Optional Bytes that may be specified in Extended DPDU

The Extension DPDU defines one byte, the Extended DPDU Type, which can have values from 0-255. This value may be used in future specifications, which may define additional header bytes and format of data after the header.

3. Backwards Compatibility

This specification uses a standard encoding and is fully backwards compatible.