We are currently investigating an interoperability issue where ****GigaBlox SFP may fail to establish link with certain third-party 1G SFP devices, even though the same GigaBlox hardware works correctly with other devices.
This issue does not affect all third-party switches. In our testing, GigaBlox SFP has successfully linked with some third-party SFP equipment, but not with others. Communication between two GigaBlox SFP devices operates normally.
We are actively investigating the root cause and working toward a fix or recommended configuration.
The following behavior has been observed:
| Configuration | Result |
|---|---|
| GigaBlox SFP ↔ GigaBlox SFP | Works ✅ |
| GigaBlox SFP ↔ third-party switches | Sometimes fails to link |
| GigaBlox SFP ↔ Ubiswitch (Another BotBlox product) | Works ✅ |
| Ubiswitch ↔ third-party switches | Works ✅ |
When the issue occurs, the link may remain down even though the cable, SFP module, or remote device works correctly in other combinations.
The issue appears to occur during low-level 1G serial link establishment between GigaBlox SFP and certain third-party devices. The leading theory is that the issue is caused by a low-level 1G serial interface compatibility problem involving PCS mode, SGMII/1000BASE-X behavior, auto-negotiation, or SGMII MAC/PHY-side role expectations.
SFP ports do not all behave identically, even when they are all advertised as “1G SFP” or “1000BASE-X compatible.” At the electrical and protocol level, different devices may handle link bring-up differently. This can include differences in:
Some third-party devices appear to tolerate these differences and link correctly with GigaBlox SFP. Other devices may be less tolerant and fail to establish link.