Premier Inn Wifi – If only it were consistent.

I recently heaped praise on Premier Inn for providing a good wifi service in one of their hotels.

Sadly, this is not consistent across all their properties. I’m currently staying in another Premier Inn just down the road from the one with the good wifi (which was already full for this evening).

The wifi performance here isn’t great at all…

This is as good as it got. Fail.
This is as good as it got. Fail.

It does have sensibly laid out 5GHz and 2.4GHz spectrum like the other Premier Inn, so it seems the wifi architecture is sound, however what’s different here is the backhaul technology.

The other property was on what appeared to be a VDSL line from a more specialist business ISP. It also had the advantage that it was only shared between about 20-odd rooms.

This Premier Inn is much larger, but based on the ISP (Sharedband) it is likely to be using a link-bundled ADSL2 connection, and is shared amongst many more users – about 140 rooms. I’ve noticed several other Arqiva-managed hotspots using Sharedband as the backhaul technology, and these all have suffered from very slow speeds, high latency and signs of heavy oversubscription and congestion.

Notice the “star rating” on the Speedtest above. One star. Lots of unhappy punters?

I’m currently getting better performance on a 3G modem. (No 4G coverage on my provider in this area.)

It would be great if Premier Inn could offer a more consistent experience in it’s wifi product, and I mean a consistently good experience such as the one I enjoyed just up the road in Abingdon, and not the lowest common denominator of the congested barely useable mess here.

They aim for a consistent product in the rest of their offerings and for the most part achieve it, however if I was only staying here in this property, I’d be asking for a refund for the wifi charge.

Update at 1am in the morning, after the fire alarm went off around 11.30pm and caused the hotel to be evacuated…

I can just about get 3Mb/sec down (and less than 256k up) out of the connection here now, and I assume the large majority guests are sleeping. Still less than great. This is very obviously based around oversubscribed link-bundled ADSL stuff.

A hotel that got wifi right

Normally the one to highlight when something is done badly, I also want to give praise where it is due.

I’m currently staying in a Premier Inn in leafy Abingdon. The data service here that I’d normally tether to is next to non-existent, dropping out all over the place. It looks like I’m in the shadow of some structure, between me and the Three UK antenna. There are also a couple of water courses in between, which might be hindering the signal.

So, I’m forced onto one of my pet hates, paid-for hotel wifi. Remember that Premier Inn are marketed as a “no frills” hotel – but they are almost always spotlessly clean and consistent.

It was either pony up for that or go and track down (and pay for) an O2 PAYG data sim, as I do at least have line of sight from my room here to one of their masts.

Firstly, I fired up Wifi Explorer, and took a look at what is deployed here.

Nice, uncrowded 2.4GHz spectrum, sensibly placed channels.
Nice, uncrowded 2.4GHz spectrum, sensibly placed channels.

Not only was the 2.4GHz likely to work okay, but they also had 5GHz too!

Wow! 5Ghz as well.
Wow! 5Ghz as well.

So, I decided that it was worth a spin. I signed up for the free half hour. Then I actually found I could get real work done on this connection, so I gave it a speed test.

Reasonably speedy too. I'd guess it's a VDSL line.
Reasonably speedy too. I’d guess it’s a VDSL line. Might get crowded later, I guess?

Not only have they got 5GHz, but they have recently slashed their prices. Some would say that it should be free anyway, but £3 for the day, or £20 for a month seemed a reasonable deal, especially if you’re staying in a Premier Inn a lot (I’m actually back here again next week).

I’ve not tried connecting multiple devices simultaneously using the same login, but I suspect you can’t, which is possibly the only downside.

However, big props to the folks at Premier Inn for actually having a wifi install that works, even if that means having to pay for it. I’ve seen much worse services in high-end hotels which have under-provisioned, congested (and often expensive) 2.4GHz networks.

Credit where it is earned, indeed.


Update: Sadly, it seems Premier Inn have decided we can’t have too much of a good thing, and need to manage our expectations. It’s alleged that they have therefore plotted with those dastardly people at Arqiva to make Premier Inn wifi universally shit.

Please read this item from Bill Buchan, which reports that the wifi is now clamped to 2.5Mb/sec on the premium “ultimate” offering.

The question I’ve got is if the “ultimate wifi” is, as they market it, 8x faster than the free wifi, then I make the free wifi out to be <500Kb/sec.

I can just imagine a load of product management muppets sat around some buzzword infested meeting room table, cowed by groupthink, agreeing this is a good idea.

Waiting for (BT) Infinity – an update

I mentioned in my last post about my partner’s Mother moving home this week, and how it looks like BT have missed an opportunity to give a seamless transition of her VDSL service.

The new house was only around the corner from the old one, so should be on the same exchange, and maybe even on the same DSLAM and cabinet. It had previously had VDSL service, judging from the master socket faceplate.

20140624_103830

Was the jumpering in the cab over to the DSLAM still set up? Well, we dug out the old BT VDSL modem and HomeHub 3, and set those up.

Guess what…

20140626_144809The VDSL modem successfully trained up. The line is still connected to the VDSL DSLAM.

However, it’s failing authentication – a steady red “b“. Therefore it looks like the old gear won’t work on the new line.

But then the new HomeHub 5 they’ve needlessly shipped out won’t work either: we set that up too, and get an orange “b” symbol.

Evidently, something isn’t provisioned somewhere on the backend. Maybe the account credentials have been changed, or the port on the DSLAM isn’t provisioned correctly yet.

Does this look like a missed opportunity to provide a seamless transition, without the need for an engineer visit, or what?

 

When parents-in-law move homes – a tale of being “default” tech support

Sheesh BT.

The MiL has moved. Around the corner from her old house. She had BT Infinity (BT’s Retail FTTC product) at the old house. She ordered the service to be moved. The voice service was activated on the day she moved, but not the Internet access.

The new house has previously had FTTC with the last occupant, it has the FTTC faceplate. One can only assume that the “double jumpering” to the FTTC MSAN is still in place too.

I wouldn’t mind betting that it’s even coming off the same bloody street cab/MSAN.

Can we just take the old Homehub 3 and VDSL modem over and plug those in? Oh no.

BT have sent a new Homehub 5 and scheduled an engineer visit for Friday, 5 days after she’s moved in.

It just feels a bit wrong, and maybe even on the crazy side. In theory this could have been done as a simultaneous provide – i.e. both the voice and the internet service brought up at the same time, and in this case potentially without an engineer visit!

Who knows why it’s not happened. Certainly the MiL wouldn’t have known to ask for a “sim-provide”, but should she have to?

“Ambassador, with these Atlas probes, you’re really spoiling us…”

Okay. So I only expect the Brits to get the title of this. Though if you’re desperate to be in on the “joke”, watch this YouTube video of an old British TV ad for some chocolates.

One of the things I do for the community is act as a “RIPE Atlas Ambassador” – that’s someone who helps distribute RIPE Atlas internet measurement probes into the wider Internet community. The Measurements Community Builders at the RIPE NCC send me a box of Atlas probes, I go to conferences, meetings and other get togethers and I give them out to folk who would like to host a probe, along with answering any questions as best I can.

Recently, Fearghas McKay of the IX Scotland steering group asked me if I had any data from the Atlas project on internet round-trip time for probes located in Scotland, to get to services hosted in Scotland, and if I could talk about it at a meeting of IX Scotland participants.

This is a fairly similar exercise to the one I did for Northern Ireland.

One of the challenges I was faced with was the distinct lack of source data. Firstly, there weren’t that many Atlas probes in Scotland to begin with, and those which are there are mostly located in the “central belt” – around Glasgow and Edinburgh. The furthest North was a single probe in Aberdeen, and Scotland is a big country – it’s around 300 miles from the border at Gretna to Thurso, one of the most northerly towns on the Scottish mainland, as far again as it is from London to Gretna. That’s not even counting the Orkneys, Shetlands or Hebridean Islands, which have their own networking challenges.

The second problem was that of those probes, only three at the time were on an ISP connected directly to IX Scotland, and one of those was down! The majority were on consumer broadband providers such as BT and Virgin Media, which aren’t connected to many regional exchanges.

I saw attending the IX Scotland meeting as a good chance to redress the balance and extend the usefulness of the Atlas platform by distributing probes to networks which could improve the coverage.

This has resulted in what is currently the most Northerly probe in the UK being brought online in Dingwall, not far from Inverness, thanks to the folk at HighNet. They’ve also got a few other probes from me, so expect to see more in that area soon.

Most Northerly Probe in the UK
Most Northerly Probe in the UK

HighNet aren’t connected to IX Scotland yet, but maybe now they’ve got access to this instrumentation it might help them make a business case to follow up on that.

I also issued a number of probes at UKNOF in Manchester last week and I’m looking forward to seeing where they turn up.

I’d really like to get some of the community broadband projects in the UK instrumented, such as B4RN and Gigaclear. These bring some of their own challenges, such as issues with equipment at the customer premises that can actually handle the available bandwidth on the connection! It would also be great to be able to draw comparisons in performance between the community fibre service and the slower ADSL service provided over long copper tails in those areas.

Releasing a bottleneck in the home network, Pt2 – at home with HomePlug

As promised the next instalment of what happened when I upgraded my home Internet access from ADSL to FTTC, and found that I had some interesting bottlenecks existing in what is a fairly simple network.

Last time, I left you hanging, with the smoking gun being the HomePlug AV gear which glues the “wired” part of the network together around the house.

HomePlug is basically “powerline networking”, using the existing copper in the energised mains cables already in your walls to get data around without the cost of installing UTP cabling, drilling through walls, etc. As such, it’s very helpful for temporary or semi-permanent installations, and therefore a good thing if you’re renting your home.

The HomePlug AV plant at Casa Mike is a mix of “straight” HomePlug AV (max data rate 200Mb/sec), and a couple of “extended” units based on the Qualcomm Atheros chipset which will talk to each other at up to 500Mb/sec as well as interoperate at up to 200Mb/sec with the vanilla AV units.

One of the 500Mb units is obviously the one in the cupboard in the front room where all the wires come into the house and the router lives. However, despite being the front room, it’s not the lounge, that’s in an extension at the back, so the second 500Mb unit is in the extension, with the second wifi access point hanging off it so we’ve got good wifi signal (especially 5GHz) where we spend a lot of our time. The other 200Mb units get dotted around the house as necessary, wherever there’s something that needs a wired connection.

So, if you remember, I was only getting around 35Mb/sec if I was on the “wrong side” of the HomePlug network – i.e. not associated with the access point which is hardwired to the router, so this was pointing to the HomePlug setup.

I fired up the UI tool supplied with the gear (after all, it’s consumer grade, what could I expect?), and this shows a little diagram of the HomePlug network, along with the speed between each node. This is gleaned via a L2 management protocol which is spoken by the HomePlug devices (and the UI). I really should look at something which can collect this stuff and graph it.

HomePlug is rate adaptive, which means it can vary the speed dependant on conditions such as noise interference, quality of the cabling, etc., and the speed is different for the virtual link between each pair of nodes in the HomePlug network. (When you build a HomePlug network, the HomePlug nodes logically seem to emulate a bus network to the attached Ethernet – the closest thing I can liken it to is something ATM LAN emulation, remember that?)

The UI reported a speed of around 75-90Mb between the front and the back of the house, which fluctuated a little. But this doesn’t match my experience of around 35Mb throughput on speed tests.

So where did my thoughput go?

My initial reaction was “Is HomePlug half-duplex?” – well, turns out it is.

HomePlug is almost like the sordid love child conceived between two old defunct networking protocols, frequency-hopping wifi and token ring, after a night on the tequilas, but implemented over copper cables, using multiple frequencies, all put together during an encoding technique called Orthogonal Frequency Division Multiplexing (OFDM).

Only one HomePlug station can transmit at a time, and this is controlled using Beaconing (cf token passing in Token Ring) and Time Division Multiplexing between the active HomePlug nodes, orchestrated by the concept of a “master” node called a “Central Coordinator”, which is elected automatically when a network is established.

When you send an Ethernet frame into your HomePlug adaptor, it’s encapsulated into a HomePlug frame (think of your data like a set of Russian Dolls or a 1970’s nest of tables), which is then put in a queue called a “MAC frame stream”. These are then chopped up into smaller (512 byte) segments called a PHY block, the segments being encrypted and serialised.

Forward error correction is also applied, and as soon as the originating adaptor enters it’s permission to transmit (it’s “beacon period”), your data, now chopped down into these tiny PHY block chunks, is striped across the multiple frequencies in the HomePlug network. As they arrive at their destination, acknowledgments are sent back into the network. The sending station keeps transmitting the PHY blocks until the receiving node has acknowledged receipt.

Assuming all the PHY blocks that make up the MAC frame arrive intact at the exit HomePlug bridge, these are decrypted, reassembled, and decapsulated, coughing up the Ethernet frame which was put in the other end, which is written to the wire.

The upshot of this is that there’s a reasonably hefty framing overhead… IP, into Ethernet Frame, into HomePlug AV MAC frame, into PHY block.

Coupled with the half-duplex, beaconing nature, that’s how my ~70Mb turned into ~35Mb.

The thing to remember here, the advertised speed on HomePlug gear is quoted at the PHY rate – the speed attainable between HomePlug devices, which includes all the framing overhead.

This means, where HomePlug AV says that it supports 200Mb/sec, this is not the speed you should expect to get out of the ethernet port on the bottom, even in ideal conditions. 100Mb/sec seems more realistic and this would be on perfect cabling, directly into the wall socket.

Talking of ideal conditions, one of the things that you are warned against with HomePlug is hanging the devices off power strips, as this reduces the signal arriving at the HomePlug interface. They recommend that you plug the HomePlug bridge directly into a wall socket whenever possible. Given my house was built in the 1800s (no stud-walls, hence the need for HomePlug!), it’s not over-endowed with mains sockets, so of course, mine were plugged into power strips.

However, not to be deterred, I reshuffled things and managed to get the two 500Mb HomePlug bridges directly into the wall sockets, and voila: Negotiated speed went up to around 150-200Mb, and the full 70-odd Mb/sec of the upgraded broadband was available on the other side of the homeplug network.

Performance is almost doubled by being plugged directly into a wall socket.

In closing, given everything which is going on under the skin, and that it works by effectively superimposing and being able to recover minute amounts of “interference” on your power cables, it’s almost surprising HomePlug works as well as it does.

This HomePlug white paper will make interesting reading if you’re interested in what’s going on under the skin! 

80 down, 20 up, releasing a bottleneck in the home

A couple of weeks ago, I upgraded the Internet connectivity at home, from an ADSL service which could be a little bit wobbly (likely due to poor condition on some of the cabling) and usually hovered between 2Mb and 3Mb down, to FTTC – reducing the copper run from about 3.5km down to about 200m.

The service is sold as “up to 80Mb/sec” downstream, with upload of up to 20Mb/sec, which turns out to be achievable on my line, as my ISP’s portal reported the initial sync as 80Mb, and this gives around 75Mb of usable capacity at the IP layer once you’ve knocked off the framing and encapsulation overheads.

I eagerly headed off to thinkbroadband.co.uk and speedtest.net to run some tests. They confirmed I’d only get 40Mb/sec until I replaced my trusty but ageing Cisco 877 – that’s one bottleneck I already knew about and had a replacement router coming. But, never the less, I was happy with a >10x uplift on the previous downstream speed, and off I went happily streaming things, as can be seen from my daily usage…

Guess when I switched to FTTC?
Guess when I switched to FTTC?

Yes, some of that usage in the first day or two would have been repeatedly running speed tests in giddy abandon at the bandwidth at my disposal, but the daily usage is now generally higher.

There’s a number of reasons that could be behind that, but I suspect that among the most likely are services which support variable bit-rate video delivery, which include things such as YouTube and BBC iPlayer will be automatically upping to the higher quality stream.

The new router arrived on the 9th, and it was off with the speedtests again… and that’s where I found an interesting bottleneck in the house.

I could happily get 75Mb/sec in one room – where the router and main access point was. However, in the lounge, which is in an extension at the back of the house, I could only get around 30Mb/sec, despite having an access point in the same room.

I’ve ended up with multiple access points in the house, because the original “cottage” was built in 1890 and has fairly thick walls made of something very, very tough (from experience of hanging up pictures) which is also largely impervious to radio waves it seems, while the extension is attached to the “outside” of one of the original external walls, as well as being the furthest point away from where the Internet access comes into the house. This meant that I wasn’t left with much choice but to infill using a second wireless AP.

But both APs are of a similar spec and support 802.11a/b/g/n, and I was connecting on the less congested 5Ghz spectrum on both. So, where was the bottleneck?

The attention turned fairly quickly to the HomePlug AV network which I was using between the front and back of the house. It hadn’t caused me much concern in the past, but now it was prime suspect in my quest to wring the maximum out of my shiny new upgraded circuit.

Finding the longest piece of cat5 cable I have (a big yellow monster of a cable), and running that through the middle of the house to the AP, revealed that my suspicions were correct, but I also knew that the bright yellow cable snaking through the kitchen couldn’t stay there.

In the next few days I learned more about HomePlug than is probably healthy, and that will form the basis for my next article…