ION Non-Standard Extensions¶

This document describes several non-standard extension blocks and administrative records used by NASA JPL's ION (Interplanetary Overlay Network) DTN implementation. These extensions are defined in a draft CCSDS Orange Book and provide additional functionality for custody transfer, reporting, and quality of service that exceeds the baseline RFC 9171 specification. A custom QoS extension block, based on the BPv6 Standardized ECOS block, is also implemented by ION.

Integration Context¶

These extensions are used within the ION DTN implementation to optimize custody transfer signaling, status reporting, and quality-of-service management in constrained delay/disruption tolerant networking environments.

Extension Blocks¶

Custody Transfer Enrichment Block (CTEB)¶

The Custody Transfer Enrichment Block (CTEB) provides additional metadata related to the custody transfer process. It is defined in the draft CCSDS Orange Book on Bundle Protocol custody transfer.

• Block Type: 13
• Structure: The CTEB is represented as a CBOR list containing:
  1. Sequence Number (int): The sequence number associated with the custody transfer.
  2. Sequence ID (int): The identifier for the sequence.
  3. Block Source Admin EID (EID): The EID of the administering node.

In bespokebpv7, this is implemented in the CustodyTransferExt class within ext_functions.py.

Compressed Reporting Extension Block (CREB)¶

The Compressed Reporting Extension Block (CREB) allows a bundle to request specific types of status reports in a compressed format. It is defined in the draft CCSDS Orange Book on Bundle Protocol reporting.

• Block Type: 14
• Structure: The CREB is represented as a CBOR list with the following optional fields:
  1. Sequence Number (int)
  2. Sequence ID (int | None)
  3. Status Report Flags (flags): A bitmask specifying the requested reports.
  4. Block Source Admin EID (EID | None)
  5. Report To EID (EID | None)

Fields may only be omitted from the end of the list (trailing omission). If an interior field is None while a later field is set, serialization raises ValueError. Callers wanting to set a later field must supply explicit values (e.g. 0 or an EID) for all earlier ones.

Report Flags¶

The status_report_flags field uses the following bitmask:

In bespokebpv7, this is implemented in the CompressedReportingExt class within ext_functions.py.

Quality of Service Extension (QOS)¶

The Quality of Service Extension Block is a custom ION extension based on the BPv6 Standardized ECOS (Extended Class of Service) block. It allows for the specification of class of service parameters that influence bundle scheduling and forwarding behavior within the ION network.

• Block Type: 193
• Structure: The QOS extension block is represented as a CBOR list with the following fields:
  1. QoS Flags (int): Bitmask of QoS control flags.
  2. Class of Service (int): The ECOS class of service value.
  3. Ordinal (int): The ECOS ordinal value.
  4. Data Label (int): An optional data label for extended classification.

In bespokebpv7, this is implemented in the BPQExt class within ext_functions.py.

Compressed Admin Records¶

ION utilizes compressed versions of administrative records to reduce bandwidth consumption for signaling. These are also defined in the draft CCSDS Orange Book.

Compressed Custody Signal¶

The Compressed Custody Signal is used to communicate the acceptance or refusal of custody for one or more bundles in a single record.

• Admin Record Type: 13
• Structure: A CBOR list [type, map], where the map keys are disposition codes and values are lists of bundle sequences.
• Disposition Codes:
• CT_ACCEPTED (1): Custody accepted.
• CT_REFUSED (-1): Custody refused.
• Bundle Sequence: Each sequence is represented as [dest_seq, first_seq_num, seq_range].

In bespokebpv7, this is implemented in the CompressedCustodySignal class within admin_records.py.

Compressed Report Signal¶

The Compressed Report Signal allows for the aggregation of multiple status reports into a single administrative record.

• Admin Record Type: 14
• Structure: A CBOR list [type, map], where the map keys are report reasons and values are lists of bundle sequences.
• Report Reasons:
• RECV_REPORT (0)
• FWD_REPORT (1)
• DELIV_REPORT (2)
• DEL_REPORT (3)
• CT_ACCEPT_REPORT (4)
• CT_REJECT_REPORT (5)
• Bundle Sequence: Each sequence is represented as [dest_seq, first_seq_num, seq_range], with an optional fourth element for the Block Source Admin EID.

In bespokebpv7, this is implemented in the CompressedReportSignal class within admin_records.py.