BT SmartHub2 & Network Setup Upgrade Options

ChuckMountain

Distinguished Member
I know it’s slightly different but the Virgin media super hub 4 VoIP still works in modem only mode. (That’s the way I have it anyway)
 

tom 2000

Distinguished Member
If you want to keep your BT line you have to use a Smarthub 2. It’s BT’s proprietary voip service. You could always change to another voip provider if you want to use a different router. If you simply want better wireless you could turn off wireless at the SH2 and add one or more wireless points . I use a repurposed router for this.
As I say it is a hypothetical interest. I have a Smarthub 2 installed on FTTP and have had "The email" from BT regarding DV but it is not yet active. I have no complaints about the SH2 nor its predecessor the HH5. I also have additional APs using configured Netgear Routers, HH5 and Apple Time Capsule and it all works fine.
I cannot help being intrigued by the "can" and "cannot" claims around the Smarthub 2.
 

mickevh

Distinguished Member
With Digital Voice roll out underway I am reading with hypothetical interest various discussions regarding the necessity of having the Smart Hub 2 as a router in order to facilitate its landline function and whether it can be used as a modem and the difficulties of dual NAT. None of which I understand. I naively thought its DHCP function would be turned off and an alternative router put on the network side rather like using an old router as an access point but in reverse.
Is that not possible?

I commend you to take a look at the block diagram of a SOHO router attached to the "Using Two routers together" FAQ pinned in this forum. It hopefully illustrates what''s going in inside a SOHO router and where traffic flows.

For those routers that offer it, "modem mode" (BT SmartHub2 definitely doesn't have it - my mother has one and I've checked) disables everything except the WAN port, the modem and (usually) one of the LAN ports (lets say port 1 for the purposes of discussion) so traffic only flows WAN<-->MODEM<-->LAN1 and (effectively) bypasses everything else. Thusly, we thence need "something else" to function as the router/NAT/Firewall at the edge of your network (ie another "router") and thusly it almost always needs to be the first thing downstream of LAN1. Plus you need a replacement DHCP Server, though technically that could be anywhere (it doesn't have to reside inside a router.)

Without modem mode, if you deploy a second router then you have two routers in the pathway. That's not necessarily a "bad" thing - the Internet is made up of millions of routers and big enterprise network often have dozens of them. But it has consequences and it's not doing what most newbies think.

Let's use two routers as an example: You can create ISP<-->rtr1<-->rtr2<--everything else. But that's created an infrastructure consisting of two LAN's - one between rtr1<-->rtr2 and one rtr2<--everything else.

A definition of a "LAN" is a set of infrastructure such that if a station connected to that infrastructure sends out a network broadcast (ie a packet destined for "all station") it reaches all stations. IE a "LAN" defined the extent that a broadcast can reach. Routers do not forward broadcasts, they ignore them. Switches and AP's do forward broadcasts.

So with multiple router, we create multiple LAN's (called "broadcast domains" in the jargon) which cannot talk to each other. Routers are the "gateways" between LAN's. To get traffic from one LAN to another, we need to do "special" things with IP addresses and routing rules in the routers. Again, do-able, but most SOHO users wouldn't want to have to learn how and deal with this and cope with all the "exceptions" that need special handling. And a lot of SOHO routers lack the ability to suitably configure them even if one had the expertise.

Routers sit at the "edge" of a network (LAN) providing a connection (a "gateway") to "other" networks - which in the SOHO use case almost always means "the rest of the world via your ISP" - routers do not sit in the "middle" of a network "bossing" it.

So in the SOHO use case, unless you are an interested hobbyist or have specific needs, it's almost always most convenient to have a single LAN (broadcast domain) with connection to the rest of the worlds facilitated by one router that sits at the "edge" of your network and terminates the incoming ISP link. It's just a matter of convenience to also have that device do NAT (which you need to facilitate multiple devices accessing the public Interrnet) and a firewall (to provide some protection to your network from the public Internet) and for a "network in a box" solution also bundle it with a built in ethernet switch and Wi-Fi AP. Not least because it can be supplied pre-configured and "just work" when it's turned on without any data networking expertise to set it up.
 
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tom 2000

Distinguished Member
I commend you to take a look at the block diagram of a SOHO router attached to the "Using Two routers together" FAQ pinned in this forum. It hopefully illustrates what''s going in inside a SOHO router and where traffic flows.

For those routers that offer it, "modem mode" (BT SmartHub2 definitely doesn't have it - my mother has one and I've checked) disables everything except the WAN port, the modem and (usually) one of the LAN ports (lets say port 1 for the purposes of discussion) so traffic only flows WAN<-->MODEM<-->LAN1 and (effectively) bypasses everything else. Thusly, we thence need "something else" to function as the router/NAT/Firewall at the edge of your network (ie another "router") and thusly it almost always needs to be the first thing downstream of LAN1. Plus you need a replacement DHCP Server, though technically that could be anywhere (it doesn't have to reside inside a router.)

Without modem mode, if you deploy a second router then you have two routers in the pathway. That's not necessarily a "bad" thing - the Internet is made up of millions of routers and big enterprise network often have dozens of them. But it has consequences and it's not doing what most newbies think.

Let's use two routers as an example: You can create ISP<-->rtr1<-->rtr2<--everything else. But that's created an infrastructure consisting of two LAN's - one between rtr1<-->rtr2 and one rtr2<--everything else.

A definition of a "LAN" is a set of infrastructure such that if a station connected to that infrastructure sends out a network broadcast (ie a packet destined for "all station") it reaches all stations. IE a "LAN" defined the extent that a broadcast can reach. Routers do not forward broadcasts, they ignore them. Switches and AP's do forward broadcasts.

So with multiple router, we create multiple LAN's (called "broadcast domains" in the jargon) which cannot talk to each other. Routers are the "gateways" between LAN's. To get traffic from one LAN to another, we need to do "special" things with IP addresses and routing rules in the routers. Again, do-able, but most SOHO users wouldn't want to have to learn how and deal with this and cope with all the "exceptions" that need special handling. And a lot of SOHO routers lack the ability to suitably configure them even if one had the expertise.

Routers sit at the "edge" of a network (LAN) providing a connection (a "gateway") to "other" networks - which in the SOHO use case almost always means "the rest of the world via your ISP" - routers do not sit in the "middle" of a network "bossing" it.

So in the SOHO use case, unless you are an interested hobbyist or have specific needs, it's almost always most convenient to have a single LAN (broadcast domain) with connection to the rest of the worlds facilitated by one router that sits at the "edge" of your network and terminates the incoming ISP link. It's just a matter of convenience to also have that device do NAT (which you need to facilitate multiple devices accessing the public Interrnet) and a firewall (to provide some protection to your network from the public Internet) and for a "network in a box" solution also bundle it with a built in ethernet switch and Wi-Fi AP. Not least because it can be supplied pre-configured and "just work" when it's turned on without any data networking expertise to set it up.
So it might work some of the time?
 

mickevh

Distinguished Member
It may well work all of the time - it's not particularly an unusual configuration, in business environments with professional IT staff to manage it, it's not too dissimilar to the sort of thing we do often.

However, I would invite you to "turn the question on it's head" somewhat and ask "what have I gained by using multiple routers...?" If such a configuration has increased the complexity for no useful gain, why bother...?

The "complexities" introduced include additional latency (lag) which may be a big deal for online gamers, uPNP will no longer work for dynamically opening port forwards from the Internet for any apps that utilise it (though uPNP doesn't seem to be so popular these days,) you've two rounds of NAT translation which again can be a big deal for online gamers, separation of LAN's (which could be both a good and bad thing - for example, it's one way to implement a DMZ or a "guest" network,) and greater administrative complexity as you'll possibly need to set up some static routes in the routers to get traffic between the two LAN's - and some SOHO routers don't have the facility to do so.

So what's the gain? If it's "just" an additional Wi-Fi hotspot, then there's a much simpler, and possibly cheaper, way to avail an extra Wi-Fi hotpot without adding any of the extra complexity such as above - buy a stand alone Wi-Fi Access Point instead. Or if you want a small AP/switch combo, a SOHO "router" that has an "AP mode" or crippling a SOHO router as described in the "Using Two Routers Together" FAQ will do the same job.

So I suggest it's a question akin to something like "can I put this jet engine in a milk float to make it fast?" Well, with enough ingenuity and expertise, I'm sure we could. But why would we want to if we just want a fast car rather than and engineering challenge/project, isn't it simpler and likely to be more reliable to just go and buy fast car instead...?
 
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tom 2000

Distinguished Member
It may well work all of the time - it's not particularly an unusual configuration, in business environments with professional IT staff to manage it, it's not too dissimilar to the sort of thing we do often.

However, I would invite you to "turn the question on it's head" somewhat and ask "what have I gained by using multiple routers...?" If such a configuration has increased the complexity for no useful gain, why bother...?

The "complexities" introduced include additional latency (lag) which may be a big deal for online gamers, uPNP will no longer work for dynamically opening port forwards from the Internet for any apps that utilise it (though uPNP doesn't seem to be so popular these days,) you've two rounds of NAT translation which again can be a big deal for online gamers, separation of LAN's (which could be both a good and bad thing - for example, it's one way to implement a DMZ or a "guest" network,) and greater administrative complexity as you'll possibly need to set up some static routes in the routers to get traffic between the two LAN's - and some SOHO routers don't have the facility to do so.

So what's the gain? If it's "just" an additional Wi-Fi hotspot, then there's a much simpler, and possibly cheaper, way to avail an extra Wi-Fi hotpot without adding any of the extra complexity such as above - buy a stand alone Wi-Fi Access Point instead. Or if you want a small AP/switch combo, a SOHO "router" that has an "AP mode" or crippling a SOHO router as described in the "Using Two Routers Together" FAQ will do the same job.

So I suggest it's a question akin to something like "can I put this jet engine in a milk float to make it fast?" Well, with enough ingenuity and expertise, I'm sure we could. But why would we want to if we just want a fast car rather than and engineering challenge/project, isn't it simpler and likely to be more reliable to just go and buy fast car instead...?
As I said my interest is purely hypothetical but there are few people out there perplexed at having to use a Smarthub 2 for their Digital Voice telephony and also wanting their favourite router at the end of their LAN and being told it cannot be done.
 

varkanoid

Active Member
BT made a hash of my regrades order. It was all so I could get the new BT TV Box as one of mine was dying. First off they cancelled my order without explanation which included Digital Voice. Then my second order I did without Digital Voice as I decided not to bother so they sent my the Premium DV Handset with Alexa with my new TV Box. Then when they phoned to say sorry for cancelling my order I told them about the mess with the 2nd order so they sent me a return bag for the Alexa phone and my old TV box. So sent both back but instead of receipting my TV box they receipted my WIFI Disc which was not even part of the order and credited me with £30. Then they said my old TV box was still to be returned and they were going to charge me for it. Another complaint filed and another phone call from them corrected it all but so far they have not asked for the £30 back even though I have told them.

Super Hub 3 is meant to be out in July too which is WIFI 6 capable so might see if I can get that. If it wasnt for the fact I do trials for BT and I still am on a contract thats £10 cheaper broadband than advertised I would have swapped out, but I also like their TV service.
 

mickevh

Distinguished Member
Super Hub 3 is meant to be out in July too which is WIFI 6 capable so might see if I can get that. If it wasnt for the fact I do trials for BT and I still am on a contract thats £10 cheaper broadband than advertised I would have swapped out, but I also like their TV service.

Did you mean "SmartHub3"..? IIRC "SuperHubs" are Virgin Media, unless you are suggesting you are changing ISP.
 

matt5000

Active Member
Following on from my previous updates on here.... I have an electrician coming next week to have a look at running ethernet cabling from the router to a few rooms in the house (probably via outside walls) and installing some ethernet sockets ion the walls. TBH I have neither the inclination nor guts to attempt it myself.
Depending on what he says re. that, I will be investing in the Asus ZenWifi XT8 (2) to replace the SmartHub 2 and employ ethernet backhaul. Will also run an ethernet cable indoors from the new router via a switch to all the A/V equipment (not too far from the router's location). Potentially a third XT8 box given the size of the house and will wire in as many of the games consoles and A/V as feasible and use the wifi (2 SSIDs - 1 for 2.4 and 1 for 5) for the phones, iPads, echos, Ring cams etc...
I guess there'll be champions and detractors to this approach but I have got to take the plunge - just one SH2 and some Devolo powerlines with 4 xboxes, 2 PS4s, 3 computers, work laptops, 5 TVs, Apple TV boxes, Sky Q boxes and dozens of phones, iPads, echos, cams and other IoT stuff, most of which is on the SH2 or Devolo wifi (with only a BT Infinity 2 speed), something has to give.
 

varkanoid

Active Member
Did you mean "SmartHub3"..? IIRC "SuperHubs" are Virgin Media, unless you are suggesting you are changing ISP.

Yeah got a bit mixed up then.
 

varkanoid

Active Member
Asus ZenWifi XT8

Just double check the spec as I've been reading the reviews saying its needs a modem and it doesnt have a port for the connection from the master socket. Smart Hub 2's have built in modem's.
 

matt5000

Active Member
How did you decide the hardware you intend on using; Asus Zenwifi?

Just double check the spec as I've been reading the reviews saying its needs a modem and it doesnt have a port for the connection from the master socket. Smart Hub 2's have built in modem's.
So I have settled (99%) on the Asus ZenWifi via reading reviews of loads of routers and mesh systems. These XT8s consistently seem to get great reviews and positive YouTube reviews as well demonstrating their capabilities. They may not be the best in every respect (i.e. speed, price etc.) compared to others (e.g. Orbi etc) but overall tick the boxes I need in the most consistent way.

Re. the modem, correct they don't have that capability but I still have my old Openreach Huawei HG612 modem from my pre-SmartHub days and it seems I can use this from the wall socket and connect the modem to the XT8 via an ethernet cable to the WAN port.
 

tom 2000

Distinguished Member
So I have settled (99%) on the Asus ZenWifi via reading reviews of loads of routers and mesh systems. These XT8s consistently seem to get great reviews and positive YouTube reviews as well demonstrating their capabilities. They may not be the best in every respect (i.e. speed, price etc.) compared to others (e.g. Orbi etc) but overall tick the boxes I need in the most consistent way.

Re. the modem, correct they don't have that capability but I still have my old Openreach Huawei HG612 modem from my pre-SmartHub days and it seems I can use this from the wall socket and connect the modem to the XT8 via an ethernet cable to the WAN port.
You can figure out Digital Voice as and when it arrives. That could be a couple of years.
 

varkanoid

Active Member

tom 2000

Distinguished Member

matt5000

Active Member
They’ve already switched it on for me so I have one of the adapters that connects wirelessly to the SH2 but I won’t miss a landline when I mothball the SH2.
 

tom 2000

Distinguished Member
They’ve already switched it on for me so I have one of the adapters that connects wirelessly to the SH2 but I won’t miss a landline when I mothball the SH2.
So you are doing without a landline?
 

varkanoid

Active Member
So you are doing without a landline?

When you get digital voice you lose the "landline" its turned off. You cant have analogue and digital voice at the same time its one or the other. I ended up keeping the analogue voice when they offered my digital voice although I wish I hadnt now. When I get the Smart Hub 3 then I will take the Digital Voice option.
 

tom 2000

Distinguished Member
When you get digital voice you lose the "landline" its turned off. You cant have analogue and digital voice at the same time its one or the other. I ended up keeping the analogue voice when they offered my digital voice although I wish I hadnt now. When I get the Smart Hub 3 then I will take the Digital Voice option.
I didn’t mean it in that way. Matt stated he had been switched to DV. He is using or is about to use a non BT router. So he will lose telephoney. That’s what I meant by landline.
 

matt5000

Active Member
I didn’t mean it in that way. Matt stated he had been switched to DV. He is using or is about to use a non BT router. So he will lose telephoney. That’s what I meant by landline.
Yes, once I mothball the Smarthub 2, I'll lose my "landline". However, given the only time that rings is when people call from the "local conservation association offering money to qualifying people aged 40 - 80 blah blah blah" or such like, I won't miss it.
Interesting that my BT bill hasn't reduced as a result of the line rental for the telephony part no longer being relevant, with it all handled digitally.
 

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