XGS1930-28 and XS1930-10 support for 2.5G SFP GPON modules

malakudi

I've searched the group but I found only some old messages about XG1250 or XGS1210.
I have a SFP GPON module which supports 2.5g on SFP. I also have XGS1930-28 and XS1930-10 but both only offer support for 1g/10g on SFP+ ports.

Is it possible to support 2.5g as well? GPON module is GPON-ONU-34-20BI from FS.
Zyxel also has a similar GPON module with 2.5g SFP support.

Is there a way to make it link at 2.5g speed? It now only works when I have set fixed speed at 1g. It doesn't work at auto or 10g.

Zyxel_Melen

Hi @malakudi,

Your understanding of the situation is correct. The lack of HSGMII support in the XGS1930-28 and XS1930-10 switches is the primary reason for their incompatibility with 2.5G SFP GPON modules. This is a hardware limitation, and as such, it's beyond the scope of what can be achieved through firmware enhancements.

Zyxel_Melen

Hi @malakudi,

Thanks for asking. XGS1930-28 and XS1930-10 only support 1G & 10G on SFP+ ports. Therefore, using a 2.5G transceiver or GPON is not recommended. Additionally, we have listed our Zyxel transceivers on the switch datasheet which are well-tested. Please also note that we can’t guarantee the third-party transceiver or GPON will work well on our Switch.

XS1930 datasheet

XGS1930 datasheet

malakudi

Competition (Ubiquity and Mikrotik among others) do support SFP at 2.5g with those GPON modules. Zyxel GPON SFP module (model is PMG3000-D20B) works with products from those companies, but not with Zyxel switches? I find this at least embarrassing for Zyxel, having own product not work with their other own products.
Is this something that can be fixed with a firmware upgrade in the future? Or there is a hardware limitation and SFP+ ports cannot work at 2.5g on those switches?

What is needed is support for HSGMII on the SFP ports, in order for those modules to work at 2.5g . Can this be supported?

Zyxel_Melen

Hi @malakudi,

Your understanding of the situation is correct. The lack of HSGMII support in the XGS1930-28 and XS1930-10 switches is the primary reason for their incompatibility with 2.5G SFP GPON modules. This is a hardware limitation, and as such, it's beyond the scope of what can be achieved through firmware enhancements.