GigaBlox SFP seems not to work

BotBlox Hardware
1

Hi all together,

I’m currently working on a demonstrator for a system architecture. We got some other parts like SPE Blox and Giga Switch working fine.

However, the GigaBlox SFP is making some trouble. The setup is as follows:

  • 2x PC with linux, ethernet interface configured to 1Gbit/full duplex/autonegotiation off and fixed ip address
  • 1x GigaBlox SFP (powered with 24V DC source)
  • 1x 5port gigabit ethernet switch (level one “GEU-0521” or “UMC-GA1F2T”)

PC - Switch - SFP - fiber cable (0.5m) - SFP - Switch - PC

I cannot reach the other PC with “ping”. What I tested successfully and what works properly is:

  • PC - GigaBlox SFP - PC (so, the Gigablox SFP seems to run)
  • PC - other switch - SFP - fiber cable (0.5m) - SFP - other switch - PC (using two of the same switches or different ones like mentioned above) (so, the SFP modules are matching and the fiber cable is ok)

Can you please help me to get the GigaBlox SFP running? I read in the documentation, there is no managing, so for my opinion it should run.

Best regards, Daniel

2

It usually because of the SFP type not being supported.

What is the make and model of the SFP you’re using?

3

Ok, is there a list of supported SFPs?

Currently I use a “SFP-GE-BX 1000Base SFP 1310/1490 10km” and on the other switch the matching “SFP-GE-BX 1000Base SFP 1490/131010km”.

4

Have you tested the SFPs independently of GigaBlox SFP?

5

Yes, as I described above using two 5 port switches with each one SFP slot.

6

Tell me more about your power supply setup for GigaBlox SFP

7

The supply is a regulated laboratory power supply with a very stable output. Currently, only a GigaBlox SFP and one SPEBlox are connected. Contrary to my initial statement, they are supplied with 15.0 V. At the moment, they draw 127 mA (no traffic, no SFP mounted).

8

With SFP mounted and trying to “ping” I have about 187mA of current drawn.

9

Are there any more tests I can do and provide you results? Is maybe the GigaBlox SFP defect?

10

Thanks for the information. Ok your setup seems fine and thanks for confirming the SFPs are working.

PC - Switch - SFP - fiber cable (0.5m) - SFP - Switch - PC

When you say “Switch” above, I guess one of the switches is a GigaBlox SFP and the other switch is a GEU-0521 or UMC-GA1F2T?

Can you tell me what LED activity you see on GigaBlox SFP in this setup?

The type of SFP module you’re using (SFP-GE-BX) is compatible with GigaBlox SFP. The issue appears to be when GigaBlox SFP is connected to another SFP switch via the SFP port.

GigaBlox SFP is only compatiblie with 1000BASE-X SFP modules, which yours is. The switch on the other side would also have to be using 1000BASE-X, so that matches, and should work.

This could be a tough one to solve because there’s actually a lot going on under the hood when using 1000BASE-X. My suspicion is that a mismatch in how both switches handle 1000BASE-X autonegotiation is the cause.

As some next steps, can you try the following:

  1. Turn auto-negotiation back on, on both PCs. We’ve seen that auto-negotiation settings can seem to “propagate” through from a copper link to the SFP link on switches. We’re not entirely sure how or why. But try turning auto-neg back on, on the PC connected to GigaBlox SFP first, then test, Then turn it back on, on the other PC connected to the other switch.

  2. Try disconnecting and reconnnecting each part of the link (PC 1 ↔ GigaBlox SFP, GigaBlox SFP ↔ SFP, SFP ↔ SFP, SFP ↔ other switch, other switch ↔ PC 2)

  3. Can you test GigaBlox SFP to see if there’s any issue on the SFP port? We do test each board but occasionally a faulty one can slip through the net. Do you have another SFP device you can use with GigaBlox SFP to test its SFP connection, or do have another GigaBlox SFP you can use?