Brother Enterprise OID Mapping

Source of truth: the SNMP reads and derivations performed by the Brother script in Print Audit Facilities Manager ICE (BrotherCommon). The binary blob layout and record ids were cross-checked against the open-source brother Python library (Apache-2.0) and its captured DCP-L3550CDW data.

Implementation: agent/scanner/vendor/brother.go, constants in common/snmp/oids/oids.go. Tests: agent/scanner/vendor/brother_test.go, which also parses agent/scanner/testdata/brother_snmp.json (HL-L8260CDW).

Validation status: the existing HL-L8260CDW fixture ends before the ...5.5 subtree, so the blob and table parsers are verified only against reference data. Capture a walk of 1.3.6.1.4.1.2435.2.3.9.4.2.1.5 with the SNMP walk capture tool to validate them on a real device.

All Brother private OIDs below are relative to 1.3.6.1.4.1.2435..

Detection

Check	Notes
`sysObjectID` starts with `1.3.6.1.4.1.2435.`	Brother enterprise
`sysDescr` or model contains `brother`	Case-insensitive; this is Print Audit’s check
`sysObjectID` under `1.3.6.1.4.1.674` with the Brother IEEE OID present	Dell-branded Brother. The Dell service tag is at `1.3.6.1.4.1.674.10898.1.1.1`. Not implemented.

How values are collected

Kind	Query	Notes
Identity, panel, counter and maintenance blobs	batched GET (`BaseOIDs`, `MetricOIDs`)	Missing OIDs are ignored
Function and scan counters	WALK (`MetricTableOIDs`)	Rows are matched by a type-code column, not by index
Supplies and trays	standard Printer-MIB tables	Private maintenance values are merged over them

Identity

Key	OID	Notes
`serial_number`	`2.3.9.4.2.1.5.5.1.0`	Print Audit prefers it over `prtGeneralSerialNumber`
`firmware_version`	`2.3.9.4.2.1.5.5.17.0`	Often contains a `YY.MM.DD` date
`firmware_version` (fallback)	`2.4.3.1240.6.5.0`	Older models
`model_name`	`2.3.9.1.1.7.0`	IEEE 1284 device ID; the `MDL:` (or `MODEL:`) field
`status_messages`	`2.3.9.4.2.1.5.4.5.2.0`	Front-panel text. Only used when it is valid UTF-8

Info blobs

brInfoCounter (2.3.9.4.2.1.5.5.10.0) and brInfoMaintenance (2.3.9.4.2.1.5.5.8.0) are OCTET STRINGs made of records:

<id:1> <flag:1> <len:1> <value:len bytes, big-endian>   ... 0xFF

0xFF ends the blob. When an id repeats, the first record wins. Modern firmware uses flag=01, len=04.

Counters (`5.5.10.0`)

Id	Key	Notes
`0x00`	`page_count`, `total_pages`	Overrides `prtMarkerLifeCount`
`0x01`	`mono_pages`
`0x02`	`color_pages`
`0x06`	`duplex_pages`	Only in the `brother` library; Print Audit does not read it

Example (DCP-L3550CDW): 00 01 04 0000064b = 1611 total, 01 ... 000002c5 = 709 mono, 02 ... 00000386 = 902 color, 06 ... 0000021a = 538 duplex.

Maintenance (`5.5.8.0`)

Ids are tried in the order listed. The first valid one wins.

Key	Percent ids	Enum id	Ratio id
`toner_black`	`0x6F`, `0x81`	`0x31`	`0xA1`
`toner_cyan`	`0x70`, `0x82`	`0x32`	`0xA2`
`toner_magenta`	`0x71`, `0x83`	`0x33`	`0xA3`
`toner_yellow`	`0x72`, `0x84`	`0x34`	`0xA4`
`drum_life` (black drum)	`0x41`, `0x80`	`0x7F`
`supply_drum_cyan`	`0x79`	`0x76`
`supply_drum_magenta`	`0x7A`	`0x77`
`supply_drum_yellow`	`0x7B`	`0x78`
`fuser_life`	`0x6A`
`transfer_belt`	`0x69`

Level encodings:

Percent: the value is percent × 100, so 0x0A28 (2600) means 26%. Non-zero values below 100 are not in this scheme and are skipped. For example, the DCP-L3550CDW reports 0x81 = 30, so black uses 0x6F.
Enum: 1 OK, 2 low, 3 replace, 4 no unit. This only fills a missing level; 3 and 4 become 0%.
Ratio (legacy, len=02): byte0 / byte1. For example, a1 01 02 04 14 means 4/20, which is 20%.

Private percentages override the public prtMarkerSuppliesTable level, as in Print Audit, which notes that each source can be more complete on some models.

Function counters (`brCounterTable`, `2.3.9.4.2.1.5.5.52.21.1`)

Column 2 is a type code and column 3 is the count in the same row.

Code	Key
1	`print_pages`
2	`fax_pages` (fallback only)
3	`copy_pages`
4	`copy_color_pages`
5	`print_color_pages`
6	`fax_color_pages`
7	`print_mono_pages`
8	`fax_mono_pages`
9	`copy_mono_pages`

Derivations (as in Print Audit):

fax_pages = fax color + fax mono. If both are zero, code 2 is used.
On mono devices without a color split, the print and copy totals are counted as mono. A device counts as color when it has color pages or a cyan toner.

Scan counters (`brScanCounterTable`, `2.3.9.4.2.1.5.5.54.2.2.1`)

Column 1 is a type code and column 3 is the count.

Code	Key
1	`scan_adf_simplex_pages`
2	`scan_flatbed_pages`
3	`scan_adf_duplex_pages`

scan_adf_pages = simplex + duplex. scan_count = the sum of all three.

Known gaps

Dell-branded Brother devices are not detected.
The per-color counters (0x12–0x15) and the image counter (0x16) in brInfoCounter are documented by the brother library but are not used.
The agent’s metric merger keeps only numeric vendor keys and status_messages. Serial and firmware still come from the per-vendor serial OID path.