Forum Discussion

legacy1's avatar
legacy1
Alessandro Volta
11 hours ago

A theory as to why VM does not have modem mode on hub 5x

Its possible from what I can make out that in some areas the XGS-PON needs a tag which is a set number or is untagged so you might be thinking how does the hub know? And it doesn't so in router mode it sends two DHCP out one with a tag the other untag and then it knows what to do with the rest of the traffic.

So that the problem you enable modem mode but the hub does not know if it should tag your outgoing traffic or not now if it was a tag if you had a switch to tag out to the hub then problem then is do the ports on the hub accept tag packets? Because in router mode the ports on the hub accept untag then the internal WAN can tag them or not out.

In which VM have screwed us due to the hub 5x hardware and network setup for modem mode with this hub which only 

2 Replies

  • Adduxi's avatar
    Adduxi
    Very Insightful Person

    Maybe move to a “proper” ONT solution and run the authorisation from it?  I believe this is how Openreach work?

  • Roger_Gooner's avatar
    Roger_Gooner
    Alessandro Volta

    There would be no problem if VM has a separate ONT for XGS-PON as it has for RFoG as the user simply connects their own router. However the hub 5X, a combined ONT/router, causes problems as, being designed as a single, unified computing platform, means you can't just disable routing functions whilst maintaining full PON functionality to implement a "modem mode".

    Nobody else in the UK provides a combined ONT/router, and whilst some foreign ISPs do, e.g. AT&T with its BGW320, none of them has a modem mode. When VM wholesales its network (called NetCo) the hub 5X will be rebranded for ISPs, and ISPs will do the selling, support and billing.

    So, why did VM go for the hub 5X? It's because all previous hubs combined the modem and router in one box, so VM's gone for consistency. Unless there is a big stink about loss of modem mode by ISPs (in which case VM can develop a separate ONT), I can't see VM doing anything about it.