Tag Archives: broadband

Still lying through their teeth…

In an incident yesterday in Reading, a downed router on BT’s network took out 9,000 homes. If you believe the press release.

If you actually check however, you’ll find that BT has once again lied. Plus.net’s user graph (remember that Plus.net is a BT subsiduary?) alone shows a drop of nearly 25,000 users.

How does a nationwide broadband and telephony provider in this day and age allowed to get away with such a crap non-resilient network design and still be handed the sole country-wide monopoly?

BT lying again (update)

One of the telecoms engineers in my workplace spoke to a source inside BT and found out the true story behind the two outages. Last Friday was not a power cut. A card in a router locked up, and rather than replacing it BT took the decision to simply reboot it and hope it doesn’t happen again.

This goes against general practices in any large datacentre where you have a multitude of people relying on a single device to be working properly 100% of the time – when something that critical fails, you replace it immediately. It also means they really don’t have any redundancy as it appears there was no second card or router to take over when the first failed, and that means a 2-6 hour outage while engineers are gotten out of their beds, travel to site, diagnose and fix.

BT lying again (update)

So it seems I was right, given that this morning once again the entire of Northern Ireland, Scotland and parts of England all lost their broadband connections again. Except this time BT is blaming an unnamed hardware vendor for the issue, again at the Edinburgh datacentre.

Imagine the broadband access for the entire of California, of even just a large city like New York going out for hours on end. There would be a senate hearing on the cause, loss of manhours for businesses and public outrage. In the UK… our government just gives the incumbent telco some more money and a tells them to try and not do it again.

BT lying again

There was an overnight outage where BT’s Edinburgh datacentre lost power. Now bearing in mind that the BRAS’s in this datacentre service pretty much the entire of Northern Ireland and Scotland, and parts of the North of England, why would they claim that only 20,000 homes were affected?

My workplace specializes in providing DSL to businesses in Northern Ireland, and I know for a fact that every single one of them was down aside from a small of handful of lines that we have in England. These are lines spread across the entire province, from Belfast to Derry. None of my neighbors had working broadband either, except for the two that were using Sky LLU. My Dad didn’t and he’s on Plusnet, many miles from where I live.

20,000 homes is about an 8th of the numbers of homes in Belfast alone, never mind across Northern Ireland, Scotland, or the North of England. Why won’t BT admit to the real number of homes affected? Because then people might realize how utterly incompetent they are to design such a widely used and relied upon system to be able to be take down nearly half the country because of a supposed power outage in a single location (which in a properly built datacentre, should be nearly impossible).

BT – Liars and idiots. Can someone remind me again why we gave these people the telecoms monopoly?

IPv6 Subnetting – You and your customer

There’s this great debate in the IPv6 world about how to chop up your allocation into assignments for your customers. Typically, most ISPs are being handed a /32, and general guidelines say to allow for a /48 per DSL/leased line/cable customer.

However a lot of people are asking, why not a /64?  Quoted below is the sort of answer you’re likely to receive on NANOG, by one Mark Smith:

There are a variety of scenarios where customers, including residential, will benefit from having multiple subnets. They may wish to separate the wired and wireless segments, to prevent multicast IPTV from degrading wireless performance. They may wish to segregate the children/family PC from the adult PC network or SOHO network, allowing the subnet boundary to be an additional Internet access policy enforcement point. They’ll need separate subnets if they wish to use a different link layer technology, such as LoWPAN. They may wish to setup a separate subnet to act as a DMZ for Internet facing devices, such as a local web server for sharing photos with relatives. Game consoles may be put in a separate subnet to ensure file transfers don’t interfere with game traffic latency, using the subnet ID as a QoS classifier.

This answer is quite simply unrealistic. It’s the answer of a typical geek with no sense of perspective as to what the average consumer wants. It’s the opinion of what Mark Smith the network engineer and geek would want.

In the real world, most consumers of domestic internet services have absolutely no concept of IP addresses let alone subnetting, VLANs, segregation or quality of service. Most domestic networks are a single flat subnet with NAT to a single IP address and no servers that would require port forwarding, and rarely an IPTV system, but those are usually setup to use special triple-play routers configured by the ISP. Most domestic users just want to be able to plug stuff in and have it work.

Now, people will argue that there are more IPv6 addresses than there are atoms in the world. However that argument isn’t as good when you are assigning 1,208,925,819,614,629,500,000,000 IP addresses for just 2 or 3 devices. It’s a grossly inefficient waste no matter what you say. Not to mention that if you’re one of the big cable or DSL providers with millions of customers, it makes much more sense. Each barely used /48 that you throw out contains 256 /64’s.

As such, I personally am inclined to go for the default of a /64 per customer, but allow for a /48 should they need it. There is absolutely no point in issuing a /48 subnet to someone who is never ever going to use it… it’s just laziness, which is what got us into the current situation with IPv4 in the first place.

BT Fail :: Part 2

A new level of fail from our friends at BT Wholesale. They have actually willingly provided proof that they do not read fault reports the first time around:

Yes.. that is a grand total of 43 seconds from reporting the fault to BT Wholesale rejecting it. This was even reported via KBD, which lets you confirm that the user has already attempted to replace his router, cables, filters and even tried from the test socket. 43 seconds is not enough time for most people to type that long-winded reply about SFI appointments, let alone for BT to run the necessary diagnostics to determine if there is a fault or not.

At my place of work we have suspected that BT was doing this for a long time as all too often, and 9 times out of 10 blatently obvious faults are rejected with the message “not due to a network fault”. Now I have a handful of faults, some where it was customer some, but some where there was genuine faults such as the DSLAM being faulty where BT has denied anything being wrong and cleared the fault in less than a minute.

Further musings on measuring bandwidth

A few further thoughts on things that people forget to take into account when attempting to measure bandwidth:

  • When measuring bandwidth, attempt to use a site or tool that is close to your ISP. If you’re in the UK and you try to test your connection using a site hosted in the US it’s never going to give you a decent idea of your speed. I recommend Speedtest.net, as it’s a single tool that can test to a multitude of different locations and will give you a much better idea of exactly how your line is performing.
  • Remember to allow around 10% for overheads. An 8Mb ADSL line will top out at 7.2Mbps. This is due to overheads for the ADSL line itself: a certain amount of bandwidth is required to manage your packets that will not be visible on any web-based bandwidth test.
  • Any download requires a certain amount of packets to be sent in the opposite direction. Usually these are acknowledgement packets to assure the server you are downloading from that everything is being received okay (or not, as the case may be). Again, that magic 10% figure is the one to watch out for. A 1Mbps download will roughly need a 100Kbps upload. If you are using up all your upload bandwidth, your download bandwidth will be poor.