ASN.1 encoder

Encodes typed records into an ASN.1 BER file (for example telecom CDR files). Flow types are generated from an ASN.1 module definition, the same way the ASN.1 decoder does it; every record received on Input is encoded and appended to the current file, which is emitted on Output.

Pins

Pin	Kind	Types	Description
Input	input	generated root type (<flow namespace>.<RootType>)	One record per call.
Output	output	Viaducta.Plugins.Files.Types.ViaFileStream	The encoded file, emitted when its batch ends, per record without a batch, or when the file reaches MaxFileOpenTime (records without a batch). Name is CDR-<yyyyMMdd-HHmmss>-<file sequence, 10 digits><ext> (TS 32.297) or ASN-<yyyyMMdd-HHmmss>-<file number since start, 6 digits><ext> (raw), UTC.

Configuration

Field	Type	Default	Description
AsnDefinition	ASN.1 module (editor)		The module text. Triggers reconfigure.
RootTypeName	type (type selector)		Full name of the record type. Set automatically by reconfigure; triggers reconfigure.
Encoding	dropdown: BER	BER	BER with definite lengths.
Mode	dropdown: 1 STRICT, 2 RELAXED	2	1 stops on the first record that can't be encoded; 2 logs it and skips the record.
MaxDepth	integer (1-9999)	99	Maximum nesting depth of a record, protects against cyclic object graphs.
Framing	dropdown: NONE, TS32297	NONE	NONE writes concatenated TLV records; TS32297 writes a 3GPP TS 32.297 CDR file.
MaxFileOpenTime	integer, ms (0-86400000)	0	Records without a batch only: 0 = a file per record; otherwise the records go into one file emitted once it has been open (since its first record) this long.
FileExtension	text	.ber	Extension set on the produced ViaFileStream.
ReleaseIdentifier	integer (0-7)	7	TS 32.297 release identifier for the file and CDR headers. 7 writes ReleaseIdentifierExtension.
ReleaseIdentifierExtension	integer (0-255)	0	TS 32.297 release identifier extension.
VersionIdentifier	integer (0-31)	0	TS 32.297 version identifier.
TsNumber	integer (0-31)	0	TS 32.297 TS number in the CDR header (for example 6 = TS 32.250, 7 = TS 32.251).
NodeIpAddress	text		TS 32.297 IP address of the generating node (IPv4 or IPv6).
FileSequenceStart	integer	0	TS 32.297 file sequence number of the first file after start, incremented per file.
BatchScope	batch scope selector	empty	Which batch goes into one file. Empty = the closest batch producer upstream (e.g. the records of one decoded file). A component id of a batch producer upstream = the batches of that producer. None = ignore batches (see MaxFileOpenTime).

Values

The encoder accepts the values the ASN.1 decoder produces, so decoded records can be re-encoded unchanged:

ASN.1	Value
INTEGER, INTEGER64, BIGINT	any integer type, BigInteger, integral string
ENUMERATED	generated enum, integer, or the item name
BOOLEAN	bool
NULL	bool?: true = present, null/false = absent
OCTET STRING	hex string (decoder format) or byte[]
TBCD-STRING	digit string (0-9 * # a b c, odd length padded with F) or byte[]
BIT STRING	BitArray, bool[], byte[] or a 0/1 string
character strings	string, character set is validated
GeneralizedTime, UTCTime	DateTime (Unspecified = UTC, as decoded) or DateTimeOffset
REAL	double
CHOICE	ActiveChoice names the alternative; when empty exactly one alternative must be set
SEQUENCE OF, SET OF	list, SIZE constraints are checked

Behaviour

• Reconfigure (changing AsnDefinition) generates the flow classes and picks the first SEQUENCE/SET/CHOICE no other type refers to as the root, written to RootTypeName and set on Input.
• Members are written in definition order (SET members too, BER doesn't sort). Missing mandatory members, an unset CHOICE and SIZE violations fail the record with the member path in the message.
• Tagged members are IMPLICIT unless declared EXPLICIT or of a CHOICE type, which matches how the decoder reads them.
• Records in a batch (see BatchScope) are encoded into the file of their batch. When the whole batch has been processed the file is emitted with the metadata of the last record; it stays in the batch, so batch consumers behind it (Write file, ...) include it before they commit. When the batch failed the file is discarded (with TS 32.297 its file sequence number is used up). In STRICT mode a record that can't be encoded fails the batch. MaxFileOpenTime doesn't split batches.
• Records without a batch (or BatchScope None): with MaxFileOpenTime 0 every record is emitted as a file of its own; otherwise they go into one shared file emitted by MaxFileOpenTime.
• TS 32.297: CDR count, file length and timestamps (local time) are filled in when the file is closed; closure reason is 0 normal or 2 open time limit. Routing filter and private extension are empty.

Notes

• Only BER (definite length). DER/CER/PER/OER are rejected at start.
• A TS 32.297 CDR is limited to 65535 bytes (16 bit length field).
• The file sequence number is not persisted, it restarts at FileSequenceStart on every flow start.
• On flow stop, files of open batches are discarded (the batch is aborted) and records of the shared file are dropped with a warning.

Example

{ "Encoding": "BER", "Mode": "2", "Framing": "TS32297", "MaxFileOpenTime": 60000, "ReleaseIdentifier": 7, "ReleaseIdentifierExtension": 8, "TsNumber": 6, "NodeIpAddress": "10.1.2.3", "RootTypeName": "MyFlow.CallDataRecord" }

Data mapper → ASN.1 encoder → File writer