ASN.1 decoder

Decodes a binary ASN.1 stream (for example telecom CDR files) into typed records. Flow types are generated from an ASN.1 module definition; every top-level record found in the stream is emitted on Output.

Pins

Pin	Kind	Types	Description
Input	input	Viaducta.Plugins.Files.Types.ViaFileStream	The binary stream to decode (for example from a file reader).
Output	output	generated root type (<flow namespace>.<RootType>)	Called once per decoded root record.
Header	output	<flow namespace>.Ts32297FileHeader (with Framing = TS32297)	Called once per file with the decoded TS 32.297 file header, before the records. Only when connected.
Continue	continue output	any (the input)	Called with the input stream after the whole stream is decoded.

Configuration

Field	Type	Default	Description
AsnDefinition	ASN.1 module (editor)		The module text. Triggers reconfigure.
Encoding	dropdown: BER, CER, DER, OER, PER	BER	Encoding rules for primitive values.
Mode	dropdown: 1 STRICT, 2 RELAXED	2	1 stops on the first decoding error; 2 logs it and continues.
FillerByte	integer (0-255)	empty	Optional padding byte between records; filler bytes are skipped. Not used with TS32297 framing (a zero CDR length marks padding there).
Framing	dropdown: NONE None, FIXED Fixed header skip, TS32297 3GPP TS 32.297	NONE	How records are framed in the file. NONE: a raw stream of TLV records. FIXED: skip FileHeaderSkip bytes at the start and RecordHeaderSkip bytes before each record. TS32297: CDR file with file header and a CDR header per record, lengths read from the data. Triggers reconfigure (registers the Header type).
FileHeaderSkip	integer (0-1048576)	0	FIXED framing: bytes skipped at the start of the file.
RecordHeaderSkip	integer (0-65535)	0	FIXED framing: bytes skipped before every record; the record length comes from the BER TLV.
MaxDepth	integer (1-9999)	99	Maximum nesting depth of a record, protects against malformed data.
RootTypeName	type (type selector)		Full name of the type decoded at stream level. Set automatically by reconfigure; triggers reconfigure.
BatchMode	dropdown: 1 Auto, 2 Always, 3 Never	1	Whether the records decoded from one file form a batch for batch consumers (ASN.1 encoder, Write file, Bulk insert, ...). Auto: only if the input file is not already in a batch; inside a batch (e.g. a file read by Read file) the records stay in that batch. Always: a child batch per file (label = file name). Never: no batch.

ASN.1 definition

A standard module: Name DEFINITIONS [AUTOMATIC|IMPLICIT|EXPLICIT TAGS] ::= BEGIN ... END. Supported constructs: SEQUENCE, SET, CHOICE, SEQUENCE OF, SET OF, ENUMERATED, INTEGER (also INTEGER64, BIGINT), BOOLEAN, REAL, NULL, OCTET STRING, BIT STRING, OBJECT IDENTIFIER, IA5String, PrintableString, UTF8String, NumericString, VisibleString, GeneralizedTime, UTCTime, context tags [n] with IMPLICIT/EXPLICIT, OPTIONAL/DEFAULT, SIZE constraints.

CDR DEFINITIONS IMPLICIT TAGS ::= BEGIN
CallRecord ::= SEQUENCE {
  callingNumber [0] OCTET STRING,
  duration      [1] INTEGER OPTIONAL
}
END

Behaviour

• Reconfigure (changing AsnDefinition) parses the module and generates one flow class per type definition (named after the ASN.1 type, C#-friendly) in the flow namespace. The first type that is not used as a member of another type becomes the root: its full name is written to RootTypeName and set on Output. Pick another root with RootTypeName if needed.
• At start the module is compiled again; per input the stream is read record by record. When a batch is opened (BatchMode) it ends after the last record was processed downstream and before Continue: consumers commit then. In STRICT mode a file with problems fails its batch and the consumers roll back; in lenient mode skipped records don't fail it. A flow stop in the middle of a file fails its batch.
• TS32297 framing: the file header is read first (a broken header fails the file) and sent to Header; each record's CDR header must announce a data record format compatible with Encoding, otherwise the record fails. At the end the record count is compared with the header's NumberOfCdrs, and a non-zero LostCdrIndicator is reported as a warning.
• A framing error stops reading the file; the records framed before it are still emitted and the problem is reported (STRICT: the file fails).
• Decoding problems are shown as warnings; errors are also written to the log with the hex content of the offending part. In STRICT mode the first error stops decoding with an exception.

Notes

• Records are read as tag-length-value; Encoding only changes how primitive values are decoded. Use BER/DER/CER for TLV files; PER and OER streams are not structurally supported.
• Only ViaFileStream input is accepted; any other input fails with "Unsupported input type".

Example

{ "Encoding": "BER", "Mode": "2", "FillerByte": 255, "MaxDepth": 99, "RootTypeName": "MyFlow.CallRecord" }

Collect files → File reader → ASN.1 decoder → Data mapper → Bulk insert