Phone services disrupted across B.C., but emergency calls still working | Hacker News Reader

Phone services disrupted across B.C., but emergency calls still working

cbc.ca

63 pointsbitminer47 comments

I find it interesting that all our major _competing_ cell phone providers were equally affected in a pretty material way by this.

The claim (by Bell) is that a "third-party fibre line" way up in North Bend BC was the root cause of this problem..

I know providers all stick their own gear on the same towers, but I guess I didn't realize how common it was for the top-level providers (i.e. the ILECs) to lease cables (as opposed to running their own). I always assumed this was just the resellers (CLECs) who did it..

I wonder if that cable is fully third-party owned, or belongs to TELUS (the quad-play provider for western Canada) and Bell/Rogers lease capacity from them for their wireless services.

> North Bend BC

OT, but I was curious and looked it up, and there are three North Bends in the Pacific Northwest (OR, WA, and BC). What a coincidence!

Norther Bend and Northiest Bend? Or North Bendier and North Bendiest?

BC's would definitely be Northiest Bend..

It's not that bendy but definitely very northy

Based on an area information lookup, the line likely belongs to Shaw https://www.ic.gc.ca/app/sitt/bbmap/hm.html?lang=eng

Longhaul cable infrastructure is expensive. Especially in Canada where business cases are crippled by thousands of km of emptiness (no opportunity to recover investments). Providers often swap lines through IRU agreements to reduce capital intensity. I've heard but can't confirm the infrastructure in question was laid down by CP and CN rail back in the 90s. I don't know the ownership structure. But I know the railways are still involved in the maintenance.

You’re on the right track: Was called CNCP telecommunications: https://en.m.wikipedia.org/wiki/CNCP_Telecommunications

One interesting thing is that North Bend is alongside a highway/railway/river. Even if there were multiple independent cables running alongside the river, I suppose a large landslide could knock them all out. There are railway tracks on both sides of the river though, and phone lines were often run alongside railway tracks (or roads), so even though it's one valley, two fiber paths should be possible.

Ideally you'd ensure geographically diverse routes for internet fiber, but I don't know how easy that is for legacy telephony networks.

https://www.google.com/maps/place/North+Bend,+BC,+Canada/@49...

> I find it interesting that all our major _competing_ cell phone providers

Bell and Telus got together to build their networks when they upgraded to 3G. Bell runs the towers in the east, and Telus in the west. (And they got Huawei to do it for them...)

https://www.theglobeandmail.com/technology/bell-teams-up-wit...

The CEOs of these competitors literally called each other up and had a friendly about how to save themselves a few billion while eliminating the risk of any price war between eachother.

They’re literally the same network appearing as 1.

So while you have the big3 « providers » and a bazillion of their sub-brands, there’s only 2 « national » networks.

And then Rogers leases some network space from Bell/Telus as the Rogers-Ext network for some rural areas, meaning everyone is using the same gear on the same tower.

If anybody else is having issues loading the article it says a landslide damaged a fiber backbone.

I guess emergency services must have a backup system or maybe there is a low bandwidth secondary that can't handle regular call volume and prioritizes emergency numbers.

I worked on wireless infrastructure software about 20 years ago - some of the stuff that counted as 3G.

The phone does not "dial" the emergency phone number. It tells the tower that it needs to initiate an emergency call. At that point, the infrastructure bypasses all authentication/authorization/billing checks and connects to what the infrastructure knows as the local emergency service. It's a standard voice connection, made over the same channels as a normal call, with one exception: if there is no available channel, it drops a normal call to make room.

In this case, some of the potential situations could be occurring: 1) There is still backbone (backhaul) availability, but perhaps the connection to the subscriber database has been severed. No normal calls can be authenticated, but emergency calls don't get authenticated and are thus not impacted. 2) Everything is working normally but at drastically reduced capacity. With the normal load of emergency calls, there is simply not enough capacity for normal calls. If this is the case, it is possible that not all emergency calls are being completed - the emergency operations center would not have the ability to know if this was the case.

Would it be possible to flood the mast with emergency calls to drop all other calls?

Yeah and that’s a way to get some sentences.

IIRC cell towers generate temporary phone numbers and session IDs so a person in distress may use even sketchy phones without SIM or legit serial numbers to make a call for help.

This is correct. But IIRC (it's been awhile), the device also sends it's programmed hardware id to the network, which in theory would allow the device to be tracked to some extent after flooding the network. The emergency call itself doesn't require a sim or active account (atleast in Canada).

I do have a recollection of watching a network outage ticket once years ago, where someone dropped their phone in a puddle which apparently caused the device to put out interference which some techs managed to track down.

There is also this case from Florida: https://www.techtimes.com/articles/161146/20160526/florida-m...

So, if I go to California with my NY cell phone and dial 911... I get the emergency services of the tower I connected to? Was always curious who I'd get when I'm not near home.

Yes. You can always make an emergency call, without service from your actual provided, and without a SIM card.

But who answers? California 911 - because that's where I'm physically located. or NY 911 because that's where my phone is from?

California 911 - the fact that your phone is from NY is not only ignored but never referenced in the process - this isn't a great analogy but you could think of your cellphone as having a built-in walkie-talkie that it uses for emergency calls. All the mechanisms for making a normal phone call are discarded when you dial an emergency number. So, nowhere on the state diagram of making an emergency phone call, is the box that says "Tell the user to dial 1 before a long distance number" - they are two separate systems.

Routing code + emergency number does work in some countries as a normally billed emergency call. Some countries silently redirect emergency call into billing infrastructure too.

Based on your location, but I know that there's stories about location not being accurate, remember seeing a report that some Pizza app and ride sharing apps can be more accurate. Someone told me on their cell phone 911 went to state's highway patrol instead of the city police, not sure if true or not since haven't had to dial 911 from a cell phone.

However if you have VOIP, not all VOIP providers support 911 but the ones that do want you to set a 911 address on your account itself, phone number or for a specific Analog telephone adapter - ATA Device from my understanding. I know our cable company provides phone service and the old modem had a sticker warning about VOIP and E911, not sure if the new one does or not since haven't looked at it too much.

> I know that there's stories about location not being accurate

If possible, try to use a land line, because the emergency calls are often routed to a different location when made with a cellular phone. This may not be true everywhere, but at least where I live in northern CA cellular calls are routed in such a way that response time can be 20-30 minutes slower than if made via a land line. When experiencing cardiac arrest, the difference in minutes can have a profound effect.

Just guessing based on how the technology works, but I would presume that when you initiate an emergency call via a cell phone call, the best location indicator that emergency services receive is "somewhere near tower X", since you are just making a voice call.

Apps running on the phone have access to your phone's GPS and can get more precise location data, if you have allowed it. Using an emergency app (Active911, Smart911, etc) will provide more specific location data to emergency services, but these are applications that rely on data and GPS to be working and may not work in as many situations as a simple 911 call.

As far as who receives the call, I imagine it is just based on who the tower is preconfigured to forward the call to. If the tower you are connected to is close to a highway, you'll probably get highway patrol. If you're in town, you'll probably get local police.

Last I heard, calling 911 from a mobile phone in CA tends to connect you to California Highway Patrol, who usually forward your call to a more local dispatcher. Some people recommend saving the emergency number for your local police department so you can skip that step.

This is how it works in most areas. Mobile calls to 911 will go to the PSAP for a relatively large region, who will triage the call and if your address is in an area served by a more local PSAP, they will add a calltaker from the local PSAP to the line and transfer the call to them.

It's probably best to just stick with 911. That's what calltakers are used to, and trying to route around 911 means you won't get the advantages built into that system (like priority handling, mapping, etc).

Of course. Any other design would be braindamaged beyond belief.

Is this still true in the days of VoLTE and packet switching for LTE cell networks?

Are you saying the phone sends some type of flag "emergency call" rather than the actual dialed digits?

The interesting implication of this is if I'm travelling in a country with another emergency number, I can "dial" the one from my home country (which is really just the sequence to initiate "emergency call") and be connected to local services.

I can see some references to 911 working on the UK phone system where the emergency number is 999 -- but this seems to be a separate mechanism (the phone company explicitly routes this number, as well as the EU emergency number 112).

Yes, that is my understanding. Dialling 911, 999, 112, or 000 on your mobile phone will all work regardless of where you are.

Yes, that is exactly what happened back then: it was in the ratified spec. I can't believe that newer systems would be any different.

I've explicitly dialed 112 (when I actually had a reason to call 911) just to see if it worked. It worked perfectly fine.

I laughed. Your thought process at that time would be interesting to see written down.

It was certainly one of those situations that if the Seattle Police had a non-emergency number that they actually wanted you to use I'd have used that instead.

Dedicated police call numbers are always routed via regular infrastructure.

What about 01189998819991197253?

This will only work if you are currently inside a Channel 4 TV show. It is very important to remember that last "three".

Well, it does trigger an easter egg in later versions of Android...

It's also why you can possibly make an emergency call when your phone has no bars of signal displayed and won't make a regular call.

It will connect an emergency call even if the quality is well below the standards for a normal voice call.

Can confirm 999 also works in Canada after an embarrassing pocket dial in which I had to explain to the authorities I was not being threatened or under duress and it was in fact just an accident.

I believe it's not the phone that flags it as an emergency call, but the transmission tower, which has a "hardcoded" list of the emergency numbers.

This is incorrect. When I worked on LTE networks, I did work on a few problems with VoLTE based 911 service, although I didn't specialize in 911 services.

In many ways, something like an LTE tower doesn't really know what a phone call is. It just looks like packet data. So there are several fields in the signalling, that indicate that a request is related to an emergency, which should have emergency handling. This can include things like dropping other lower priority traffic, prioritizing the packets themselves on the network, etc.

But the other interesting thing is in VoLTE, you actually do a new IP assignment (to an sos PDN) specifically for the emergency call, so you have a sort of new registration to the network. This allows you to make an emergency call on any network that is available. Although scanning for an available network can take some time, so you'll likely use your own carrier if they're currently available.

Note: I've been out of the industry a few years now, and specific to emergency calls only have knowledge specific to LTE and UMTS.

I'm working from home today because my work's primary and secondary lines to our data centre are down. We have a tertiary but it's slow. So they didn't want ppl coming in to the office and using all the bandwidth

Good that emergency calls still work. In the Netherlands we had a handful of service interruptions (for some regions/providers) in the last few years, and the emergency numbers went down as well. If I remember correctly, the problems were mostly caused by software.

It depends on the infrastructure but sometimes emergency calls are routed differently, sometimes over completely different systems. There's a system in the US called GETS that allows federal, state, and local government agencies to make high priority calls over normal commercial phone systems and will also make use of government only phone lines, whatever will make the connection. The agency gets a special code and a certain phone number they dial first (just like using one of those old long distance cards). There is dedicated bandwidth just for these kinds of phone calls so even if all the lines are full, there is a guaranteed 90% call completion rate if the call volume is 8 times higher than normal.

There's a wireless version of this too although it doesn't quite work the same so I'm not sure how effective it really is.

The Netherlands has a network for the emergency services that is entirely separated from the normal phone network ("Noodnet"). It has a limited service and bandwidth and normally has no interconnection with the normal phone network (so is not intended or usable for emergency calls from the public), but is designed to be very resilient. I don't think it is used when the normal phone network is still functioning. I have no idea how they test it; it must all be rather expensive.

We experienced this in Central Washington this weekend as well (around Leavenworth and Steven's Pass). Cell service went out late Saturday night and only recovered Sunday afternoon.

It looks like this is related to another extreme weather event. An epic rainstorm. https://www.straight.com/tech/1354721/rogers-and-bell-cellph... climate change is making rain storms more powerful and intense.

I’m assuming that the link in parent post is in error and was intended to be this one[0], which specifically mentions the connection between climate change and the extraordinarily high amounts of rain having fallen in the area around the time of the outage:

[0] https://www.straight.com/life/1354586/pineapple-express-brin...

p.s. I’ve always liked that these winter rain storms coming into BC, Canada from the general direction of Hawaii are colloquially called “Pineapple Express”.

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