The recent furore over the $14K phone bill of a SingTel subscriber shows how much our phone usage patterns have changed in the last decade. Originally used for making voice calls, then moving on to SMS text messages, many of us are nowadays predominantly using our phones for mobile data communications. More specifically, we’re using our phones for mobile access to the Internet. It’s the communication tools and services that’s on the Internet that we care about, not so much the voice or text services from the mobile phone operator.

During my recent holiday trip to Hong Kong, I chose a prepaid roaming card on the basis of its cheap data services. I reckoned that I wouldn’t be making much phone calls or text messaging. It’s data that I’ll be consuming. Voice calls wasn’t important. And text messages, well, I wasn’t expecting to text much either. Furthermore, I wouldn’t even be telling anyone back home about my prepaid telephone number, so actually no one could call me or text me anyway.

This is basically what Google wants. Google’s focus on developing the Android platform will enable it to push its services. In the U.S., there is Google Voice. Although we don’t have Google Voice (yet) in Singapore, there is still Google Talk, and a bunch of other Google services. With Skype, we still get to make free IP-to-IP voice calls. WhatsApp, which is free on Android, lets us send IP-to-IP text messages, bypassing telco-based SMS charges.

Where this is going to is that the traditional mobile network operator is reduced to a basic broadband carrier service. Not very different from the home broadband network that just about anyone subscribes to at home. Pretty much every mobile network operator doesn’t like this, and they don’t want to let this happen, but I think it’s pretty inevitable where we’re all headed towards.

We already have pretty reasonably priced flat-rate unlimited (or as good as unlimited) local mobile data in Singapore. It’s pretty much the case with mobile network operators in many other developed countries. The only trouble is when you roam to a foreign network. It’s still not all that cheap even with various data roaming alliances. For example, with SingTel’s Bridge DataRoam, I would have to pay S$15 a day, or about S$105 for 7 days for the length of my last trip to Hong Kong. Using a prepaid card in Hong Kong, 7 days of unlimited data cost me only S$26.

But having to change SIM cards when you travel is inconvenient. This is particularly when you want to continue to be reachable by voice or text at your original number. Sure, you can forward your voice calls, but you can’t do the same with SMS messages.

Eventually, mobile network operators will have to accept that they have been reduced to basic data carrier service providers, and focus to deliver value in some other ways.

Meanwhile, if you want to continue having data access for your smartphone when you travel, the safest solution is to get a prepaid SIM card. No way you can end up with any accidental or unexpected charges. If you absolutely have to use your local SIM card and want to use a partner roaming data plan with it, make sure your phone is locked to the correct network, and better check regularly that it really works!

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Our original event was planned to run at the start of the year. But it was rushed, and ultimately because of lack of time and lack of organizing resources (i.e. the manpower to get the project moving), we postponed the plan. We rescheduled to target the start of the new academic year, and we also pared down our ideas somewhat… just to get something easy and simple going for the first time.

So, our first ever COM Tech Days (as we have chosen to call it), took off 2 days ago on 24th August 2011. Very simple affair. No banners. No food. But I’m quite encouraged by the response. It’s not an overwhelming crowd, but I’d say reasonably sized considering we only spammed email to the first and second year students, a freshmen orientation page on Facebook, and that’s about all the publicity we did. We didn’t even tell our staff, or people outside the school.

I’m now thinking about whether we could run this as a monthly event. Just a simple one hour talk in the afternoon just one day of every month. We could still run a bigger event once a year. But the idea of a monthly talk is to keep the momentum going, keep up the presence of the event, and continually pique people’s interest. Of course, on the other hand, there is the big issue of whether we can sustain such an effort. I’m still quite encouraged, however, that we might be able to work something out. We’ll definitely need a dedicated team of people to drive this.

One of the agenda behind COM Tech Days was to discover and meet up with students who are interested to join our Network Associates student helper program. We had been doing this every year through a Network Workshop previously. COM Tech Days replaces that.

What is this Network Associates program about? Well, most of what I’ve written before is still relevant, so read my previous post. If you’re interested, you’ll know how to contact me.

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If you’ve not heard about it, Alasdair Allan and Pete Warden announced (MacRumor link) their discovery that iOS devices recorded location data in a hidden file in iOS devices. Personally I felt this was more of a publicity stunt to raise their profile. It turns out that Allan’s and Warden’s discovery wasn’t much of a discovery anyway, because 4 years earlier, Alex Levinson, a student from Rochester Institute of Technology, already made public his discovery of about the same thing. He published his research in a computer science conference, and subsequently contributed a chapter to a book on iOS forensic anaysis. (Source: Tech-Ex and Gigaom)

Then, guess what? This isn’t even something unique about iOS. Android also does about the same thing. CNET asked Google a series of questions, and Google was apparently unable to comment on all of them immediately.

Location tracking isn’t even about the embedded features of iOS or Android, or other smartphone operating systems. Don’t you know your telco already knows where your phone is at any time? Yeah, cellular location isn’t as accurate as GPS positioning that your phone may be capable of obtaining, but it is pretty darn good too

Inside your workplace, your IT networking people also have access to location information within their network. I’m not just talking about nailing down your access to physical network points, but about location tracking using Wifi triangulation. These are enterprise wireless features that have been available for many years. Have you heard of 802.11-based asset tracking? How do you think they work?

Then there’s more and more. How about your EZ-link card? Your cash card? Some can track where you’re spending money, how much your spending, and what you’re spending on.

You are always being watched. Some way or other.

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Let’s get one important terminology straightened out first. This new network that we’re talking about is what the Info-communications Development Authority (IDA) calls our Next Generation National Broadband Network, often abbreviated to Next Gen NBN, and sometimes further to NGNBN. This NGNBN is our new Fibre-to-the-Home network project, and it is part of IDA’s IN2015 masterplan.

NGNBN is a name made up by IDA. People from other parts of the world will know what ADSL and Cable means, because they are standard industry terms. NGNBN is a Singapore thing.

My apologies if this is starting to sound like an IDA presentation with all the fuzzy high-level talk mostly uninteresting to techies… but it is important to understand (if you don’t already know) some overall structure so that you can appreciate how all the bits fall into place later.

Our NGNBN is made up of several layers:

1. The passive network layer, comprising the dark fibre that reaches into the customer premises (e.g. homes).
2. The active network layer, comprising the actual network switching.
3. The retail services layer, where service providers come in to sell customers network access.

Layers of Network

Network people like layering. The physical network medium, as you already know, comprises optic fibre. The optic fibre that reaches your home is single-mode fibre. Two cores of single-mode fibre is terminated in a Termination Point (TP) in your home. The TP is a small box (125mm x 80mm x 20mm) with two SC connectors. (I know, to network engineering people, this sounds oversized, but the reason is that the TP box includes a reel to take up some excess length of fibre cable.)

All the dark fibre cables from customer premises are aggregated into a Central Office (i.e. Telephone Exchange). There are 9 such locations:

• Tuas
• Jurong West
• Bukit Panjang
• Ayer Rajah
• Ang Mo Kio
• Orchard
• East (it’s at French Road)
• Bedok
• Tampines

Active network switches are only deployed in the Central Offices. As you know, single-mode fibre can carry signals far enough. But, are you wondering, how is it possible to have so many fibre cores from customers individually terminate into a Central Office?

The answer is in the optical technology used – GPON (Gigabit Passive Optical Network) [see Wikipedia]. Unlike Gigabit Ethernet on fibre (e.g. 1000BASE-SX or 1000BASE-LX), GPON transmits and receives on the same fibre core. Furthermore, a single core of fibre from the Central Office can be split up to 128-way toward the customer-end. In order words, a single fibre core at the Central Office is split 128-way toward the customer-end, ultimately terminating in 128 termination points (or 64 customer TP boxes, since each TP in the NGNBN design has two fibre termination points). The splitting can happen much nearer towards the customer end, such as in the MDF room within the customer building, and is accomplished with passive optical splitters.

At the Central Office end, the fibre core connects into an Optical Line Terminal (OLT). The customer-end will have a patch cord from a port on the TP to an Optical Network Terminal (ONT) or Optical Network Unit (ONU). The OLT at the Central Office is where the active network infrastructure begins. The optical distribution from Central Office to customer is entirely passive.

The OLT and ONT (or ONU, but I’ll just omit mentioning ONU for the rest of this post) terminate their respective ends of the passive optical network. The OLT-ONT can provision a variety of native services, including IP-over-Ethernet. The OLT interfaces upstream with service providers’ network services, and presents those native services to the customer at the ONT.

OLT to ONT Connection

As mentioned earlier, a single OLT port connects to multiple ONTs. Downstream traffic is transmitted on one wavelength, and upstream traffic is transmitted on a different wavelength. This means that downstream traffic from the OLT is seen by all ONTs, and all ONTs share the same upstream channel to transmit traffic.

Each ONT processes only the traffic is addressed to it, even though it can see all the traffic on that shared optical medium. Encryption is used to prevent an ONT from reading traffic addressed to some other ONT. Upstream traffic from the ONTs are time-division multiplexed on the shared optical medium.

The GPON standard (ITU-T G.984) permits several bit rates, so I’m not sure what bit rate our NGNBN has adopted. However, the industry has converged on 2.488 Gbps downstream and 1.244 Gbps downstream. This bandwidth has to be shared by all the ONTs. However, the OLT controls the optical medium and allocates time slots to ONTs. Each ONT can be provisioned with different downstream and upstream bandwidths, enabling service providers to sell different tiers of services to customers.

GPON also permits Dynamic Bandwidth Allocation (DBA) where the OLT can grant additional time slots to ONTs depending on its bandwidth demand.

Layers of Separation

Remember how networks are naturally layered, and how the NGNBN design is also layered? Well, this layering is a key foundation to enabling competition. Here’s how the NGNBN layering works:

• Wholesale Wirelines (Layer 1 Open Access): This passive optical network starting from the TP at the customer end, and the passive dark optical fibre leading up to the Central Office. The operator at this layer is the Passive Infrastructure Company, or NetCo. OpenNet is the only NetCo at this time. It’s possible (although not in the NGNBN plan) for there to be several NetCos, either operating exclusively in different geographic regions, or competitively in the same locality.
• Wholesale Bandwidth Services (Layer 2 and Layer 2 Open Access): This is the active network infrastructure, starting with the OLT in the Central Office. The ONT in the customer premise is part of this layer too. The operator at this layer is Active Infrastructure Company, or OpCo. Nucleus Connect is the first OpCo awarded by IDA. SingTel became the second OpCo in September 2010.
• Retail Services: This is the layer that provides services that customers actually buy, including Internet access services, Voice-over-IP telephone services, IP television, etc. Commercial and industry customers may even have access to a new breed of services such as CCTV networks, telemedicine, etc. The operator at this level is known as the Retail Service Provider (RSP). Right now, there are several RSPs. You probably already know who they all are… SingTel, StarHub, M1 and SuperInternet.

The way the NGNBN has been engineered thus enables a lot of flexibility and room for competition. You can buy services from different RSPs. Although there are multiple OpCos, you as a customer probably don’t get to choose OpCos directly since it will depend on which OpCo the RSP connects to. (But it is technically possible for RSP to connect to multiple OpCos, and offer customers the choice of OpCos.)

So in principle, right now, since there are two ports on the TP box, you could connect two ONTs from two different OpCo, and from the ONTs, buy multiple services from a variety of RSPs. This probably sounds rather unnecessary right now, because all the RSPs just basically offer Internet access services (some value added with telephone and/or television services), but there could well be a whole new breed of services in future.

Just so you know, the initial NetCo OpenNet is owned by SingTel (and several other partners), while the initial OpCo Nucleus Connect is owned by StarHub. So you’ve got to wonder if there is really fair competition? Well, the answer is that OpenNet and Nucleus Connect are contractually obligated to provide fair non-discriminatory services to upstream providers.

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The target audience for this game is quite different from that of SimCity. The background knowledge required is different. Although SimCity also requires you to know something about city planning, economics, etc, much of it is really common sense (at least for the kind of audience who would play SimCity).

In myPlanNet, you really need to know broad fundamentals on various network technologies, everything from data networking, mobile phone networks, broadband, etc. If not, then you had better have a great passion to learn about these things. Apart from just having fun, education seems to be the goal of myPlanNet, because there is plenty of explanations, tutorials, and illustrations. But, of course, if you are not interested in these things at all, you’re not going to like the game.

There are plenty of thing to learn. You’d see how service providers organize their infrastructure into core, aggregation and access layers. There are also edge layers as well as the “service delivery centre”. It’s not very different from how enterprise data networks are built. You’ll see what devices fit in where, and what devices are required to provision what kind of services. You’ll learn what sort of technologies lead to what opportunities, or basically what depends on what other things.

There are three starting points you can choose in the game: 1) As a landline telco; 2) As a cable TV company; 3) As a mobile phone operator. Whichever company type you begin with, you’d soon have to acquire technologies and build out services of the other type of companies which you didn’t choose to begin with, and ultimately continue progressing toward the same goal of reaching the medianet age.

The real life is not different. Look at the SingTel and StarHub (I hesitate to add M1). They both provide landline phones (although limited deployment for StarHub), digital voice, mobile, fixed and mobile broadband, pay TV, etc. Networks are converging, and whether you start out as a landline phone company or a cable TV company, you’d all end up doing the same thing.

There’s no StarHub or SingTel to compete with in this game. But I think the game will give you an appreciation of what StarHub and SingTel do behind-the-scenes and under-the-hood.

The game is not too challenging. Actually you would find it more difficult to go bankrupt (if at all possible) than with SimCity. My guess is that Cisco wants this to be an education tool. You aren’t going to learn a lot if you get stuck with economics, even though there are some simple economics that you have to manage.

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The nice thing about networking in the last decade is that everything has basically settled down around the Ethernet standard. Everything. Even Wireless LAN is basically Ethernet. Ethernet has also crept its way into Wide Area Network applications. It has simplified things for network professionals. (Actually it has made things simple enough that everyone could say they knew how to setup and run networks.)

But while everything is standardizing on Ethernet, the networking devices have become more and more complicated. There are so many things to learn and to know.

Our Catalyst 6509, for example, has been running the 8-port 10GE line card just fine. But the new 16-port 10GE line card wouldn’t come up, because it is apparently unsupported by our current firmware. Yeah, an oversight on our part not to check on the firmware requirements first. I suppose this is not too different from how some PC motherboards require a BIOS firmware update to support a new CPU. The firmware for a Catalyst 6509 is more complicated, of course. I’m always a bit apprehensive about upgrading, partly because we don’t have the luxury of a testbed to test the firmware, and the switches we’re upgrading are always “critical”.

The firmware upgrade this time around had a few surprises, but fortunately nothing as spectacular as many others we’ve been through. Someday, Cisco should think about how to make firmware upgrades for their products as idiot proof as, say, their Linksys products.

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I have been thinking about upgrading my wireless broadband router for some time. In fact, I was considering StarHub’s free Apple Time Capsule promotion last year. It does 802.11N wireless, Gigabit Ethernet wired ports, includes 500GB or 1TB of storage and printer connection sharing.

But there was no urgency when my WRT54G was still working. Of course, now things are different. So I quickly refreshed my comparison survey of the various wireless broadband router products. The Apple Time Capsule is off the list, because it is too expensive and its disk storage capability has been filled in by a Maxtor OneTouch 4 Plus direct attached storage I bought last year.

The main new feature I want is draft 802.11n support and Gigabit Ethernet wired ports. The main contenders were the Linksys WRT310N, WRT350N, WRT610N, and D-Link DIR-655. The Apple AirPort Extreme was considered too.

In the end, I bought the Linksys WRT610N. I liked that it was Dual 802.11n Band, operating at both 2.4GHz and 5GHz frequency bands. Everyone nowadays has at least a 802.11b wireless device somewhere. The 2.4GHz frequency band is extremely congested. I see a dozen Wireless LANs in my home. But the 5HGz frequency band is lesser used. It is occupied by 802.11a, which is not common. Furthermore, Dual Band 802.11n wireless broadband routers are not so common either. The reduced congestion is distinct advantage of running a Wireless LAN on the 5GHz frequency band.

The WRT610N has the new Linksys outer casing design. The device has a UFO-like shape and features internal antennas. It definitely looks nicer than their older products, and many of their competitors’ products. But the router is does not need to be looked at, so in my opinion, it is not something terribly important. Not unless it is so beautiful that you want to show it off.

The WRT610N cost $245. I don’t think it was a terribly good bargain. Considering that one can get the Apple AirPort Extreme for just $13 more ($258 with educational discount from Apple Store), which would have come with just about everything the WRT610N has plus USB printer connectivity sharing.

The AirPort Extreme looks beautiful. Yes this is something you could display in your living room (except that its white colour tends not to gel with most living room gadgets). But I’ve not used or seen the the box in operation, so I don’t know exactly what kind of configuration options there are. I am concerned about configuration flexibility because I have rather specific things I want to do. I consider myself somewhat of an expert at networking, and there are some not-so-standard things I want to do with my home network. I have used a variety of Linksys broadband products for many years, so I know what it can and cannot do. It was thus a safe choice to go with the WRT610N.

One common complaint about many Linksys products is that they get very hot. So far my WRT610N has not gotten hotter than “warm to touch”. Setup and configuration is similar to any other Linksys broadband router product, so Linksys users should be quite familiar with the administration interface. The 5GHz and 2.4GHz wireless radios are configured independently, so you can have different settings between the two Wireless LANs.

Although 802.11n is still in draft status, the WRT610N works perfectly with my MacBook (supports 802.11n in both 2.4GHz and 5GHz frequency bands as well). In the past, “draft” often means you have to buy everything from the same brand manufacturer. Fortunately 802.11n draft is sufficiently advanced for this to become a non-issue.

Just for record sake, I managed to clock about 80Mbps transfer rate from my MacBook approximately 2m aware from the WRT610N, performing scp file transfer from a PC connected to the Gigabit Ethernet port. Decent performance I guess.

Update (9 Jan 2009): I’m told that Apple’s AirPort Extreme may be dual band, but operates at only one band at a time. I.e. you can configure it to work at 2.4GHz, or at 5GHz, but not to provide wireless coverage on both 2.4GHz and 5GHz frequency bands at the same time.

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The students in this programme are called “Student Helpers”, although at some point we’d like to rename or promote this to a better sounding term like “Student Associates”. This isn’t the first programme that we’re running, but it is the first that seems to be working out. It’s a good thing, because sometimes what we find terribly exciting doesn’t quite match up to what students think or want.

What do our student network engineers do? Basically, they help us run our production networks and data centres. They will get to learn many things that are not taught in books, touch really cool high-end stuffs, and spice up their resumes.

These are real enterprise-scale operations, bigger than what you’d see in typical SMEs. We do many things that are “cutting-edge”. Such opportunities are usually not even available to fresh graduates, let alone undergraduate students. So this is really something quite exciting and valuable. Well, at least that’s how we hope our students will see it.

Of course the next question then is, what is there in it for us? Well, we have too many things on our hands, too little time, and not enough people. We could use with some help. Students are, admittedly, cheap labour. But we see this as a mutually beneficial relationship, and we hope to get some really good students onboard. It will cost us time and effort to run the programme of course, but hopefully we reap more benefits out of it than the overheads will cost us.

This is not the place for a total newbie to start learning the very basics of networking. So one thing we will tell potential students is that we expect them to come in with either some basic understanding of networking, or a willingness to put in the effort to quickly get up to speed. The right aptitude and great passion are important. After all, we are expecting them to do useful work for us, we aren’t really running a training school here.

I hope we will be just as successful (or more so) with our second batch.

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A couple of nights ago, we upgraded the firmware of our Catalyst 6509. It was not supposed to be so complicated. Making backups and copying images back and forth would take a little bit of time. Rebooting a Catalyst 6509 will also take several minutes. But we wouldn’t anticipate taking more than half hour ordinarily.

We know Murphy’s Law. Anything that can go wrong, will. Murphy’s Law came more true than we expected.

The root cause of the problem we encountered was a corrupted firmware image. What we had on disk was not what we transfered to the Catalyst 6509′s flash memory. Can it get more wrong? Yes, eventually it turned out that what we had on disk to begin with was actually also corrupted. So, of course, the Catalyst 6509 switch could not boot up from corrupted firmware.

If that was not enough, our upgrade exercise got waylaid by a few other weird hardware glitches. First, the switch indicated a “minor fault” and a “temperature alarm”. The fan tray had a red light. We realized the fans were not spinning at all. One of the line cards had an orange status light also indicating a “minor fault”. While we were puzzling over these problems, just suddenly out of the blue, both power supply units showed a “DC output failure” light, and the switch was dead. Turn off, turn on, fortunately the switch started up fine, and the fans were spinning again. Hmm, but wait, the standby supervisor module failed to come online.

It was altogether a rather strange upgrade exercise.

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We’re still looking to hire more staff to support our Network, Data Centre and IT Security operations. It is the same super engineers kind of work I blogged previously, but this a technologist position targeted at polytechnic graduates. Our priority for this position is in Network, Data Centre and IT Security operations, in decreasing order. Let me know if you’re interested.

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