4G / Huawei B535 / 2nd router problem

[GrumpyPatzer]

Hello everyone

This is my first post here.  I’m hoping you can help with a problem that is driving me mad.  Apologies for the long and rambling post, but I thought it worth giving as much background and information as possible.

I am in the Scottish Highlands with a rather unreliable ADSL2+ service from BT/Plusnet, so being able to reliably use EE’s 4G is important to us.  For some time, we have been successfully using a Poynting 4G-XPOL-A002 and Huawei B315 for 4G, via a Ubiquiti USG (which enables me to use the 4G in conjunction with the ADSL2+, such as it is).  So I appreciate that this is perhaps a slightly convoluted configuration, but it gives us the best possible broadband — which’s I say, is quite important to us, given the remote location.  Now, perhaps unwisely, I thought it might be worth upgrading the Huawei B315 to a B535-333, in the hope of gaining some extra download speed and, in addition, being able to control the configuration better than is possible with the B315 (which is fairly primitive).

The problem is that, with the USG connected to the B535 (just as I did successfully with the B315), I get absolutely no internet connection from anything connected to the ethernet and wireless that runs off the USG — which is our whole network, apart from one thing.

What works:

1.  The previous setup with USG connected to the B315: everything connected to the USG has perfect internet access.

2.  With the USG connected to the B535: ping6 (from the USG) to an IP v6 address.

3.  Internet access from an iPad connected direct to the B535’s wifi.  (This is of no practical use, because the 4G aerial and B535 are in a different building.)  The iPad is given several IP v6 addresses as well as an IP v4 one.

4.  Ping to google.com from the B535’s GUI diagnostic page.

What does not work:

1.  Nothing else from the USG or from any device connected to the its network.  (I have tried many things, including ping to an IPv4 address and ping/ping6 to a hostname from the USG.)

2.  Ping to 8.8.8.8 from the B535’s GUI diagnostic page.

This is all with the B535 in normal (DHCP) mode.  If I put it in bridge mode, nothing at all works, not even the ping6 from the USG to an IP v6 address.

Comments and (very!) tentative conclusion:

1.  The B315 appears to be operating purely as an IP v4 device, so the EE 4G network clearly tolerates that.  Whereas it “knows” that the B535 is v6-capable, so expects it to operate accordingly.  Incidentally, if I attempt to switch the B535 to IPv4-only operation, it fails to connect to the 4G network.

2.  I understand that the EE 4G network uses 464XLAT, correct?  So presumably the B535 does make use of that (which is presumably what is happening with the iPad connected directly).  But it seems entirely possible that either (a) the B535 and USG do not play well together in this regard; (b) there is a problem with the B535's 464XLAT's implementation; or (c) perhaps more likely, there is something wrong in the way I have configured the USG (although please bear in mind that it works fine with the B315, IPv4 only, of course).

3.  The fact that I can ping from the USG to an IPv6 address but not to a hostname (using either ping or ping6) makes me suspect that DNS requests are failing to work, possibly because they are not getting beyond the B535.  In fact, if I try “ping google.com” from the USG, 

Questions:

1.  Would you expect what I am trying to do — a second router (the USG) connected to the B535 — to work?

And if, at least in principle, it should:

2.  Would it have more chance of working with the B535 in bridge mode?  (Bearing in mind that even the ping6 to an IPv6 address stopped working when I tried this — although that may well be because the USG’s IPv6 config is wrong.)

3.  Any suggestions for configuration options to try?  (I have assumed DHCPv6 rather than a static IPv6 address and prefix delegation rather than static on the USG, for example.)

Any advice or thoughts that any of you can offer would be very much appreciated.  And thank you if you have taken the time to read this far!

Andrew

[Christopher_G]

Hi @GrumpyPatzer

Welcome to the community and thanks for your detailed post.

This is a bit above my level of understanding, but we do have some fantastic and knowledgeable community users who may be able to offer you some suggestions.

@XRaySpeX, @bristolian, either of you fancy having a stab at helping Andrew with this?

Chris

[GrumpyPatzer]

@Christopher_G , thank you!

If I may add a couple of things to my post earlier:

I am rapidly coming to the view that a point I made in passing in my original post — namely, that creating a APN profile with IPv4 only fails with a log message “WAN connection INTERNET_VOICE_R_UMTS1:IPv4 failed” — may be central to this problem.

1.  In fact, with both IPv4 only and v4/v6 dual stack, the B535 fails to make a v4 connection.  In the case of IPv4 only, this means that there is no 4G connection, whereas for dual stack, it is v6 only.

2.  As I understand it (possibly incorrect!), for IPv4 traffic encapsulated in v6, as per 464XLAT, the B535 should be using CLAT.

3.  However, I believe the B535 will only use CLAT in IPv6-only mode, not v4/v6 dual stack.  I surmise that with dual stack, it would expect to use a native IPv4 connection for v4 traffic, so CLAT is not enabled.

4.  But my B535 is failing to make an IPv4 session (in either dual stack or v4-only mode), so any outbound IPv4 traffic (e.g. from the USG router) fails.

5.  And, when creating an alternative APN profile (as I do for IPv4 only) the B535’s GUI does not give an IPv6-only option.  So I have no way of enabling CLAT — and no way of successfully establishing a ‘native’ IPv4 session.

So, I see two ways of making this work: find a way of specifying IPv6-only (thereby enabling CLAT, hopefully); or fixing the IPv4 session establishment failure.

Suggestions on either — or both — would be most welcome!

Thanks …. Andrew

[GrumpyPatzer]

Well, I am now convinced that the IPv4 connection failure is central to the problem I am having.  Forget about all of the IPv6 stuff for now.  Moreover, this failure seems to be specific to EE, 4G and the default APN (with the usual everywhere / eesecure / secure details):

1.  Using either the default (dual stack) or a newly created (IPv4-only) APN on 4G, my Huawei B535-333 fails to establish an IPv4 session.

2.  Using the same SIM, but old T-Mobile APN details, IPv4 works no problem.

3.  Forcing the B535 to use 3G only also establishes an IPv4 session, with an EE v4 address (rather slow and not very usable, but an IPv4 session nonetheless).

It seems pretty clear, then that this is an EE / 4G / APN problem, perhaps even specific to this mast.  Interestingly, I came across this problem, reported by @cmsdloma  which sounds very similar if not identical:

https://community.ee.co.uk/t5/Mobile-Broadband/IPv4-not-working-with-default-APN-dual-stack/m-p/1098...

The problem was "a fault / misconfiguration on [the] mast".  The fix was for EE to "reset the APN".

The mast I am connecting (or not connecting) to is just west of Invergarry (possibly ID 17486).  The cells for which the IPv4 connection is failing are 4476418 and 4476430 (bands 3 and 20, respectively).

Can anyone suggest how best to proceed with this problem?

Thanks .... Andrew

[EssexBoyEE]

Hi Andrew, I suggested to you (on another Forum) to change the APN Settings and to include TMobile and change the User and Password etc, I thought this worked for you, the TM APN will, or should still work with a 4G and 5G Connection, so you could try changing the IPV4/6 on that profile to see if that helps. 

[GrumpyPatzer]

Hello @EssexBoyEE and thanks for taking the trouble to post here, too.

Yes, the old T-Mobile APN details worked, as I mentioned in my earlier post, above.  That gave a perfectly adequate IPv4 connection (better than the EE 3G one, in fact, although nowhere near as fast as the EE 4G one I can get with the old B315 router).

But my SIM and data plan is EE, so I'm not sure what more I can usefully do with the T-Mobile details?  It's the failure to establish a 4G IPv4 connection on EE (on this local mast) that I need to resolve -- for which I think I need EE's help.

Andrew

[GrumpyPatzer]

I'm wondering if I'm being even more dim than usual .... 😮

Given that T-Mobile morphed (for want of a better verb) into EE, am I right to think that using the old TM APN details that @EssexBoyEE suggested should work fine with an EE SIM?

More specifically, is it safe to assume that this will simply use my regular EE data allowance (of which I have an ample sufficiency) without incurring any additional charges?

If so, then this seems to me a perfectly viable solution, at least for the time being!

Thanks (and apologies again for being a bit slow on the uptake).

Andrew

[bristolian]

---

@GrumpyPatzer wrote:

Given that T-Mobile morphed (for want of a better verb) into EE, am I right to think that using the old TM APN details that @EssexBoyEE suggested should work fine with an EE SIM?

More specifically, is it safe to assume that this will simply use my regular EE data allowance (of which I have an ample sufficiency) without incurring any additional charges?

---

EE was, in technical terms, a rebrand of TMUK - they adopted the ex-TM MNC/MCC while the ex-OUK codes were decommissioned.

Checking your bundle usage would be a reliable way to check.

[GrumpyPatzer]

Excellent suggestion, @bristolian 

Since connecting with my main EE SIM and the T-Mobile APN (IPv4-only), my data allowance has reduced by c.0.5GB.  That may not be absolute, conclusive proof, but it seems to me a pretty good indication that it is my existing package that is being used.

incidentally, using broadbandspeedchecker on a laptop with a wired connection to a Ubiquiti switch that is connected to the B535 via the USG, I got over 40Mbps download (with a peak rate of nearly 60Mbps showing on LTE H-Monitor).  That’s with an RSRP of -115dBm.  The mast is about 9 miles away.  Not bad, I think.

This is, in fact, the first time I have been able to make a 4G+ connection (which is why I bought the B535 in the first place), bands 3, 20 and 28, although I’m not convinced band 28 will be doing anything.

So, so long as I really can continue using the T-Mobile APN details without incurring any additional charges, this is, at least for the time being, a sufficient solution.  Although I’d still like to fix the default EE APN’s inability to make an IPv4 connection (to exactly the same cells on the same mast!).

Many thanks again to @EssexBoyEE for the T-Mobile suggestion.

Andrew

[EssexBoyEE · Accepted solution]

You almost certainly will be using the Data Allowance from your EE Account Sim Plan, otherwise the Data Usage would not be working for you, your overall EE Sim Number is identified on the Network as the Sim Identity that's linked via the Network to your Account and Status.

Changing the APN will have no effect on the above as long as the APN is accepted by the Network as being a valid APN but it does seem to have an effect somehow on the Data Access Gateway, therefor the TM APN, which is currently allowable, should provide you with a Yes/No Data Access via the Network.

I've tested a few on the EE Network and have yet to find any that degrade the Network Speeds or lock / latch to any particular Mobile Generation, ie, 2, 3, 4, 5G (other Networks differ, the most noticeable being Vodafone), what I have found in testing over time on the EE Network and APN Profiles (Especially on Huawei Routers and some Huawei, Pixel and some iPhone Phone Devices  is the Internet Gateway Access does sometimes seem to change the behaviour of IPV4 and IPV6 Internet access, EE seem to have an inheritant problem currently with IPV6, and the words EE, Huawei and IPV6 rarely fair well in the same sentence, hence why I suggested to (a long short) APN change to your Huawei Router on the Other Forum, which seemed to work for your Posted issues.

I don't normally suggest a total APN change to effectively another Network, as it can cause Network Roaming issues and in some Countries a wrong Foreign APN match could raise a Network Bandit Alarm and block the foreign Sim on thier Network.