29-03-2012 06:01 PM
Good enough or not, dude, the fact is neither BT or VF can guarantee the VSS will work with every router. I assume this is why BT can only test on the equipment they supply (unless they've got access to the thousands of routers available on the market)
Vodafone can only own one third of the set up which is the VSS and the network.
ISP's and routers can't be tested as it's out of their hands since they don't provide either the internet connection or the connection equipment.
Have you tried a different router, by any chance?
30-03-2012 10:58 AM
A further update for you:
Both product managers for Vodafone Sure Signal and BT Infinity have worked closely testing both products and have confirmed the VSS does in fact work on Infinity with the equipment supplied by BT.
Whoever you have spoken with at BT has misinformed you and BT have been made aware of this thread and are communicating to their customer facing teams that they are not to advise that the VSS does not work with BT Infinity.
BT however do not support VSS as it is not one of their products.
31-03-2012 08:09 AM
This is all very good, and as you are repeating yourself I have do the same.
WE DO NOT WANT TO USE THE BT KIT AS IT IS INFERIOR.
It is well known that BT and Vodafone have a cosy relationship, afterall BT Mobile use Vodafone's network for their mobile service? So have BT added something to their kit to make it work with VSS?
Why can't Vodafone publish what specail requirement their VSS device requires, or better yet provide one that does not special handling - no fragmented packets.
To repeat myself I don't have problems with browsing, email, skype, video streaming and my VPNs with the draytek routers - so why is the VSS not compatible???
01-04-2012 01:59 PM
Anyway, I have at last got my (v2) Suresignal working. I have tried many different combinations of routers and settings but the combination that finally worked for me is the Openreach modem -> BT Business Hub 2 (2Wire) and a modified MTU setting of 1456.
I couldn't get the newer BT Business Hub 3 to work (couldn't find where/how to change the MTU on that.
In the current working setup I have given the Suresignal a public, static IP and the firewall is off on that port of the hub. I now intend to pull the suresignal back in to my private network and see if I can get that to work.
So, 5 bars for the the first time for over a month as opposed to zero/one bar.
As a side note, Vodafone tech support have _consistantly_ told me that the Suresignal would _NOT_ work on a PPPoE connection. BT on the otherhand have repeatedly said they believe it should work, and it does.
02-04-2012 12:36 PM
Actually the problem is with the VSS as it does not meet the spec for PPPoE in the UK, which means it cannot work with the BT Infinity system. However, it seems some router manufacturers have seen this issue and allow 1500 MTU (so called Jumbo packets) to pass through by fragmenting them to 1492 MTU which is the UK standard. I think that Draytek have not modified it's routers and have not seen this issue and just reject Jumbo packets which are outside the PPPoE spec.
I have tried the BT fibre router, the Drayteks 2820 and 2750 and a modern Netgear. All fail. I am told by BT that the issue might be down to their newer DSLAMs which use Broadcom chipsets and reject any jumbo packets as they are outside spec (One BT tech person said it also rejects fragmented packets but I find this hard to believe). So even routers that can pass the Jumbo packets unchanged will still not pass the DSLAM in the cabinets (for FTTC systems).
It might be possible for a router manufacturer to "fudge" the issue by breaking up the Jumbo packets into PPPoE compliant ones and passing them through (this will need special attention when using any VPN passthrough). I hope that Draytek might yet come to our rescue and make a firmwear mod.
However, the root cause of this problem is that the VSS is not designed to work with PPPoE 1492 MTU stsyems. This nees to be amended and I understand that a relatively simple firmwear mod could make all these issues go away if only Vodafone would do the upgrade. As can be seen elsewhere there are more and more people using the newer Infinity products using PPPoE and Vodafone cannot ignore this change for ever.
02-04-2012 12:50 PM
Can you confirm what router the BT guys used as we cannot get ANY BT fibre router to work. The DSLAM in the cabinet is their latest version and is a different design. We have tried several different routers.
I seem to be getting different information from BT to you. My sources are with BT Business to Openreach, not BT Retail. Truthfully, how can BT be so sure it works when there are a growing number of people on here who are finding a problem.
My team and I here are no slouches when it comes to setting up these systems.
It might help us all, if you could put down a definitive guide to setting up the VSS on a PPPoE system. As I have also said before, I cannot use the BT Fibre hubs as I need to advanced features of better designed systems (we do prefer Draytek).
Truthfully, I am not having a go at Vodafone but it would help me (and others here) if you could mod the VSS to work on PPPoE systems. I think it is a simple matter of limiting the network MTU to 1492 or less which I believe could be done in firmwear. I truly believe this will help with the future direction of broadband in the UK and make the VSS more robust into the future. It is also true that router manufacturers could mod their hubs and modems to allow for 1500 MTU jumbo packets by fragmenting them rather than just discarding them.
02-04-2012 08:50 PM
03-04-2012 08:38 AM - edited 03-04-2012 08:40 AM
VDSL is going to become more and more popular, and people are going to want to choose the equipment they want to use. If this problem existed on ADSL and the answer was only to use one particular manufacturers bit of equipment everybody would be up in arms about it.
Vodafone do NOT make it clear when you purchase that there are compatibility issues with BT Infinity and that you are limited to one manufacturers equipment.
I am also of the opinion that this issue lies with the VSS Home Cell device, and trying to get DrayTek to make modifications is the tail wagging the dog. What happens when Netgear or D-link make a VDSL router?
Vodafone please be proactive about this and make your equipment work, and address the issue with the fragmented packets and the MTU size.
04-04-2012 12:16 PM
Hi Mike, what BT home hub did you use? I am told by BT that one of their Fibre Home Hubs (The Huwei I think) worked but the newer 2Wire business version does not as it adhers to the spec for PPPoE precisely.
BT still say that they do not support the VSS and that if it works you are lucky in that the router has been designed to allow for jumbo packets and will fragment them and pass them through.
All Vodafone need to do is to implement MTU negotiation on the VSS rather than accept a fixed MTU of 1500. This will solve all the problems and allow everyone to use whatever hardware suits their business needs..
For info, I have never had my VSS working on BT Infinity and we have tried the VSS version 1 and 2, the BT fibre hub (a 2Wire version 3), two types of modern Drayteks and a new Netgear hub. We have put the VSS into DMZ and this opens all ports through the firewall. BT advise me the newer 2Wire hubs implement PPPoE specs exactly and jumbo packets are refused. This is the root cause of the problem. BT say , even today! that the VSS will enver work with BT Infinity unless you are lucky and have a router/hub which fudges the issue.
06-04-2012 10:19 AM
OK, my team has done some extensive research and analysis and this is the current position. I apologise for some techy bits but it is needed.
Everyone knows that data is transferred on modern networks using packets which have certanl characteristics. The packets have lengths and, within them, contain the data and some control bits. The exact make up is not need for this discussion. One of the control bits within each packet is a "do not fragment" flag which can be set to off or on. We think the VSS has fixed sized packets of 1500 MTU and the eF flag is set to disallow (i.e. do not fragment).
The two wide area lan confifurations in the UK use PPPoA and PPPoE as the format standard. Most UK hoseholds use PPPoA which is a hangover from old style telephony equiment which uses ATM. Nothing wrong with that.
If you connect the VSS to an ATM style connection using PPPoA, such as ADSL systems in the UK, the MTU can be set up to 1500 without the need to fragment. Even though the VSS packets do not allow fragmentation this was never a problem as none of the packets needed any and would be sent on their way by the broadband router (I assume for this discussion that all correct ports are open and the VSS is set up correctly).
However, the BT Infinity product uses PPPoE which meets the international standards and has a maximum MTU of 1492 which means any packets which are presented to it which are larger that this (called Jumbo packets) need to be fragmented. There is no way that you can send an un-fragmented packet of MTU 1500 through a properly configured PPPoE network such as the FTTC BT Infinity one.
So, any router confronted with this problem usually fragments the packet. This is a little inefficient but it does allow the data to pass (whether in a VPN tunnel or not). As some of the data sent is not superfluous, the speed will diminish but most will not see this effect.
With the VSS, the MTU 1500 packets need to be fragmented. But the control bit within each packets dissallows fragmentation. Any modern router cannot deal with this issue and just discards the packet presented in this way. They can do nothing else.
Some older routers do allow you to ignore the eF control bit and fragment the packet anyway. BT's older hubs do this to allow for older equipement using ATM connections and MTU's of 1500. The newer routers, including BT's latest version 3, 2Wire routers stick to the standard completely and do not support legacy ATM products (such as the VSS). Modern euipment, such as PC's etc use a facility called MTU Path Discover which tests the path of the packets to their destination and set their MTU (i.e. packet length) to the minimum that they find. This is why anything running Windows XP or 7 works fine. Other than the VSS we have had no other issues swapping from PPPoA to PPPoE.
There are four possible solutions to this, some of which people have already found.
1) Use a router (usually and older one) which ignores the eF flag and fragments packets anyway down to the PPPoE standard of 1492 or less. This does waste packets but it will work.
2) Find a router as in 1) above but put it as an interface between the VSS and your network (set the eF flag to ignore within the router software). This will fragment the packets down to a lower number and the BT Infinity router sees it as normal traffic.
3) Get Draytek (and others) to allow for a eF flag enable/disable oiption in their software which then will fragment the packets ignoring the eF flag set within the packets themselves.
4) Get Vodafone to implement MTU Path Discover within the software of the VSS and set the MTU to the minimum value found, i.e. an update to the network management software to meet the more modern standards.
We are looking for an interface router which will allow for legacy ATM products (such as telephone exchanges of older design). We think a Buffalo Airstation has the necessary requirements but, as yet, can't find one to try.
I'll keep you all informed.
06-04-2012 02:05 PM
Thanks Jim, really appreciate the effort you and your team have put in.
My preferred option would be 4) Get Vodafone to implement MTU Path Discover within the software of the VSS and set the MTU to the minimum value found, i.e. an update to the network management software to meet the more modern standards.
I don't think it is reasonable for Vodafone to expect all the router manufactures to modify their firmware to accommodate VSS.
Come on Vodafone please make your equipment comply with modern standards!!!!!!
18-04-2012 07:01 PM
Hi Jimfew, apologies for my slow response, been away.
The BT Hub that I used to get things working initially was the 2wire 2701HGV-C, which is a BT Business Hub. As previously mentioned, as opposed to the very latest BT Hub, you can change the MTU setting on it. The VSS was setup in the hubs DMZ with a public, static IP, just to get things working.
I wasn't happy with that setup, or the BT hub so I now have the VSS inside my local network, I have discarded the the BT hub and I use a linux device to act as my router/firewall and the VSS still works.
I find it hard to understand what difference it makes, what kind of internet connection one has when using ANY network device locally. Unless of course, as you say, packets are being dropped due to a setting within the packet itself in which case a device would struggle. Surely though, dropping packets willy nilly does not make sense.
Now I know next to nothing about network providers and their topology so where does the pppoa & pppoe come into the equation? It must just be the bit from the cabinet on the street to your house/business? If not, any setup that currently works could easily stop working if routed through a device which drops said packets, i.e by traversing a pppoe segment.
Ok, starting to get dizzy now I can't believe in this day and age we are dependent on luck?
21-04-2012 10:52 AM
27-04-2012 12:32 PM - edited 27-04-2012 12:34 PM
I've got my Sure Signal 2 to work on FTTC WITHOUT the need to use BT's standard Home Hub Router (which does work). Im using a Draytek 2920, though the solution below should work with any PPPoE router you directly connect to the modem.
Last week i moved to FTTC and use Zen Internet as my ISP. Im using a Draytek 2920 router attached to the BT OpenReach standard modem thats provided with the FTTC installation. It was not possible to get the SS working directly attached to the Draytek 2920 due to that modem being in "PPPoE" connection mode. However, by simply connecting an old router to the Draytek router and plugging the SS in to the old router it works fine (i did the port forwarding rules for the 8,50,500,4500,123). My guess is tha the "inner network" created by old router doesn't know anything about it being on "PPPoE", so does what ever is necessary for the SS to work (perhaps handling the packet fragmenting as some are sure is important).
So, a solution that DOES WORK needs an extra "hop" of equipment between the draytek and the SS, but only the SS is on that sub-network so doesnt impact the rest of my network usage. The Draytek 2920 isn't the key bit of the solution here, it should work for any PPPoE router, but you do need to create an inner network where the WAN port of the inner router comes the internal subnet from your PPPoE outer router.
A bit more info to help others:
Wall Socket->BT OpenReach Modem->(Ext Ip) DrayTek 2920 (192.168.1.1)->Belkin N1 (Old Router)(192.168.10.1)->SS(192.168.10.2)
The rest of my network just comes directly of the 2920 just how i want it.
Initialisation & Connection to Vodafone of the SS only took about 10 minutes when setup like that.
Thanks to everyone's posts that helped lead me to this solution and I hope my post helps others achieve the same success.
27-04-2012 01:05 PM
Couple of other tips with the setup:
If your outer router supports it, then put the inner router "wan port ip" (192.168.x.x) in to the outer routers DMZ. If not, remember you'll need to port route from the outer router->Inner Router and then Inner Router->VSS (ie, two sets of rule setups) depending on whether you have PnP enabled in all places.Other options include assigning the inner router with a second public IP if you have one. All options should be fine.
Remember, The key part of the solution is using a 2nd router with subnet (ethernet in /ethernet out) inside the main outer router (PPPoE /ethernet).
28-04-2012 02:09 PM
Ok, my team and I have finally got it working today.
The problem is with the 1500 MTU (as explained previously) and the fact that the Draytek 2820 (and all the other routers we tried) would discard the "jumbo framed" packets rather than fragment them.
The answer was to allow fragmentation and ignore the "do not fragment" bit in the packet headers from the VSS.
It took ages to find the right method and I'd like to share this with you all.
In the Draytek you have to issue a telnet command to change the DFcheck flag from enable to disable. If you do a telnet help command and search the available commands then you will find the coorect one.
However, this is NOT activated by a soft reset via the web interface. It only enacts when you do a full hard reset by power cycling. Goodness knows why Draytek made this a feature but they did and it took us weeks to find this out.
Once we made the telnet DFCheck change and did an on/off power cycle, everything came on and the VSS now works properly. Effectively the Draytek has now been configured to ignore the "Do Not Fragment" flag in the packet headers and just fragments the jumbo packets down to MTU 1492 which can then be passed over the BT FTTC Ethernet backhaul network. It seems the Vodafone servers do not reject the fragmented packets and everything sets up and runs, albeit a bit slower because of the fragmentation but on the new FTTC super fast broadband network, this does not effect the performance.
Job done, hope this helps everyone. Certainly a weight off my mind!
29-04-2012 08:13 PM
15-05-2012 11:01 PM
Same kit as you so dived into the DrayTek 2820 to change the DFcheck flag.
The entry wan DF_check /? returns
%DF bit check is Disable!
What does that mean please? I assume it means already disabled but equally it could mean to use the Disable command. But how?
I would very much appreciate your feedback.
For the record the LAN address of the SS has is MAC bound to IP and also these ports are open:
1723 TCP and UDP
I am always reluctant to reboot the router but I guess I should and also power down/up SS, At this stage is a hard reset called for?
Is there anything else that I should configure in the router< I have currently the NTU set as 1492.
I have made sure that my port redirection request are for WAN2 !
16-05-2012 11:06 PM
The command was actually
wan DF_check off
So a power recycle then took place. When the internet was established, VSS was rebooted. Usual flashing of lights for around 15 minutes only to be left with the power light on. Leaving the office now but not expecting it to be magically working in the morning.
All very frustrating and out of guidance of what to do next. Anyone with any ideas here?