Cisco MGBSX1
Cisco · SFP transceiver, 1000BASE-SX · MGBSX1
what it is
A 1000BASE-SX transceiver (Cisco) in the SFP form factor, part number MGBSX1. Works over two multimode (MM) fibers (duplex), 850 nm. Reach per manufacturer: 500 m. Production year stored in memory: 2014. Revisions seen in the examined units: C. Units examined: 1.
what we read from it
The transceiver memory states explicitly that there are no optical diagnostics. The switch reads only its identity and basic signals (loss of signal, transmitter fault), without temperature, power or laser current.
A full read of the transceiver memory gives it a diagnostics score of 3 out of 15 — counted are: presence of measurements, manufacturer thresholds, alarm flags set by the transceiver itself and software loss-of-signal indication.
how we checked
The result depends on what the transceiver was read with — the same switch model in a different installation can show different data. That is why each reading is recorded separately:
- Cisco Catalyst 2960-X 48FPD-L (Cisco WS-C2960X-48FPD-L), firmware
15.2(7)E13— transceiver memory read from the console and SNMP sensors, 2026-10-11: diagnostics not shown (1 unit). Visible data: loss of signal indication (RX_LOS), transmitter fault indication (TX_FAULT), transmitter disable (TX_DISABLE), manufacturing date, reach per fiber type, standard (compliance code), chip vendor identifier, memory checksums, identity (manufacturer, part number, serial number, revision). Cable test: not tested.
The same transceiver in other switches and a comparison with other models: what each device shows.
what we cannot read
- Temperature, optical power and laser current.
parameters the transceiver returns
The list shows WHAT the device exposes — including parameters we do not use ourselves. There are no values here at all: it is a catalog of capabilities, not a reading from anyone's network. It is not a closed list either — explanation below the table.
12 parameters
| parameter | type |
|---|---|
data_produkcji | date |
numer_czesci | text — part number (PN) |
numer_seryjny | text |
oui_producenta | text — chip vendor identifier |
producent | text — vendor name from transceiver memory |
rewizja | text |
sumy_kontrolne | boolean — transceiver memory validity |
usterka_nadajnika_tx_fault | boolean |
utrata_swiatla_rx_los | boolean |
wylaczenie_nadajnika_tx_disable | boolean |
zasiegi_wlokien | numbers (m / km) for OM1–OM3 and single-mode fiber |
zgodnosc | text — standard (e.g. 1000BASE-LX) |
This is not a closed list. It comes from reading a unit we had access to — it shows what we managed to retrieve, not everything the device can return. A different firmware version, hardware variant or reading path can expose fields that are not here. If you are interested in a specific unit and a specific value — please ask; there is a good chance it can be obtained, even if you do not see it below.
List source: reading of 1 working unit (as of 2026-10-19). The list is the sum of what we observed — more units reveal more parameters, so numbers for different models are not directly comparable.