Recently, the US President, Donald Trump, made the decision to pull the US funding from the World Health Organisation. This of course has been widely condemned, and will likely get challenged, but in the meantime it made me wonder what the rest of us could do.
No, I’m not suggesting acts of violence at a “democratically” elected head of state, as tempting to some as that may be.
The US contributed a little under US$900M last year to the WHO. Could we crowd-fund that?
If 40 million of us, world wide, each donate US$25… we will exceed the funding once provided by the U.S.A. Time one president was shown how he’s just another brick in the wall!
We don’t need the U.S.A. to fund the WHO, we just need US. I did my bit… how about you?
COVID-SARS-2 is a nasty condition caused by COVID-19 that has seen many a person’s life cut short. The COVID-19 virus which originated from Wuhan, China has one particularly insidious trait: it can be spread by asymptomatic people. That is, you do not have to be suffering symptoms to be an infectious carrier of the condition.
As frustrating as isolation has been, it’s really our only viable solution to preventing this infectious condition from spreading like wildfire until we get a vaccine that will finally knock it on the head.
One solution that has been proposed has been to use contract tracing applications which rely on Bluetooth messaging to detect when an infected person comes into contact with others. Singapore developed the TraceTogether application. The Australian Government look like they might be adopting this application, our deputy CMO even suggesting it’d be made compulsory (before the PM poured water on that plan).
Now, the Android version of this, requires Android 5.1. My phone runs 4.1: I cannot run this application. Not everybody is in the habit of using Bluetooth, or even carries a phone. This got me thinking: can this be implemented in a stand-alone device?
The guts of this application is a protocol called BlueTrace which is described in this whitepaper. Reference implementations exist for Android and iOS.
I’ll have to look at the nitty-gritty of it, but essentially it looks like a stand-alone implementation on a ESP32 module maybe a doable proposition. The protocol basically works like this:
Clients register using some contact details (e.g. a telephone number) to a server, which then issues back a “user ID” (randomised).
The server then uses this to generate “temporary IDs” which are constructed by concatenating the “User ID” and token life-time start/finish timestamps together, encrypting that with the secret key, then appending the IV and an authentication token. This BLOB is then Base64-encoded.
The client pulls down batches of these temporary IDs (forward-dated) to use for when it has no Internet connection available.
Clients, then exchange these temporary IDs using BLE messaging.
This, looks doable in an ESP32 module. The ESP32 could be loaded up with tokens by a workstation. You then go about your daily business, carrying this device with you. When you get home, you plug the device into your workstation, and it uploads the “temporary IDs” it saw.
I’ll have to dig out my ESP32 module, but this looks like a doable proposition.
So, for years… decades even, our telephone service has been via the Public Switched Telephone Network. Originally intended for just voice traffic, this later became our Internet connection, using dial-up modems, then using ADSL.
The number itself gained two digits in its life-time: originally 6 digits (late 70s/early 80s), it gained a 0 at some point, then in 1996 a 3 was prepended to all Brisbane numbers.
So yeah, we’ve had our phone a long time, and the underlying technology has remained largely the same for that time period. Even the handset is the same one from all those years ago. Telecom Australia used to pay for it as a “priority service” back then as my father was working for them at the time.
By September, this will change. The National Broadband Network is in our suburb, and a little while back I migrated the ADSL2+ connection over to HFC. After a brief hiccup getting OpenBSD talking to it, we were away. It’s been pretty stable so far. Stable enough now that I haven’t had the ADSL modem connected in weeks.
At the time of migration, I could have migrated the telephone too to NBN phone, however there’s a snag: how do you access NBN phone? The answer is the ISP sends you a pre-configured ATA+Router+WiFi AP (and sometimes there’s an ADSL modem in there too). As I had decided to use my own router, I didn’t have such a device.
I asked Internode about the SIP details, and the situation is this: when they provision a NBN connection, there’s an automated process that configures their VoIP service then stores the credentials and other settings in a ACS server. They have no visibility of these credentials at all. Ordinarily, if I had purchased hardware, they would have provisioned that with credentials that would allow it to authenticate over the TR069 protocol. So without spending $200 on a device I wasn’t going to use, I wasn’t getting these credentials.
There’s another option though: VoIP. The NBN phone is actually a VoIP service, so fundamentally nothing much changes. Keeping the services separate though does give me flexibility in the future. There’s a list of VoIP providers as long as my arm that I can go with.
VoIP is notoriously difficult to set up though, I didn’t want to mess up our only incoming telephone service, so I decided to migrate the NBN phone number over to Internode’s NodePhone VoIP service which would allow me to experiment.
Requirements
So, first thing to consider is what my needs are. We have 4 devices that are plugged into the telephone line at present:
Telecom Australia Touchfone 200 wired telephone
Telstra 9200a cordless telephone base-station
Epson WF-7510 printer/scanner/fax
Maestro Jetstream 56kbps modem
Now, we don’t send many faxes (maybe two a year), and the last time that modem was used, it was to dial into a weighbridge system in Rockhampton after my workplace had moved to VoIP.
That weighbridge system was originally built in 1995 on top of computers running SCO OpenServer 5 and using SCO UUCP over dial-up lines running at 1200 baud (some of the nodes were at remote sites with dodgy phone lines). In 2013 the core servers were upgraded with new hardware and Ubuntu 12.04LTS, but the UUCP links remained as the SCO boxes at sites were slowly replaced. mgetty would answer the phone, and certain user accounts would use uucico as the “shell”. For admin purposes, we could log in, and that would give us a BASH prompt.
Any time we had a support issue at work, muggins would be the one to literally “dial in” to that site. While it’s been years since I’ve needed to touch it (and I think now there’s a VPN to that site), I wanted to retain dial-up capability if needed.
As for the faxes… the stuff we’re doing can be done over email. Getting the modem and the fax machine working is a stretch goal.
99% of the traffic will be voice traffic. I’m not sure if it’s possible to use double-adaptors with an ATA, and so for hardware I opted for the Grandstream HT814. These are available domestically (e.g. MyITHub) for under AU$130 and looked to be pretty good bang-per-buck. I just wasn’t sure how well it’d get along with the old T200.
As a contingency plan, I also ordered an IP phone, a Grandstream GXP1615 which is also available locally. That way if the T200 gave me problems, I’d just wire up Ethernet to the old point where the T200 was and put the GXP1615 there.
Since I’ve got two SIP devices, I need to be able to control incoming and outgoing call flows. So that means running a soft-PBX somewhere. Asterisk is the obvious choice here, being a free-software VoIP package with lots of flexibility. OpenBSD 6.6 ships with Asterisk 16.6.2.
Opening the account
Opening the account is simple enough. As I was porting the NBN phone number over, I just needed some details off my last Internode bill. Later when I go to do the house phone some time next financial year, I’ll be after a Telstra bill (assuming Telstra Wholesale have sorted out their CoVID-19 issues by then).
I looked at the hardware options that Internode offered… and again, it was basically the same as what they offer for their Internet service.
One thing I note is that while Internode has been a great ISP (I switched to them in 2012), their credentials as a VSP are still developing somewhat.
Initial connection
Provisioning was much less smooth than my initial ADSL connection (which was practically seamless) or the subsequent move to HFC NBN. The first bump in the road was when they emailed me:
Subject: Internode: Your Internode NodePhone VoIP service xxxxxxxxxx can’t make/receive calls yet [xxxxxxxxx]
Following activation of your NBN service, we ran some tests to make sure things were running smoothly.
We weren’t able to detect that your NodePhone VoIP service (phone number xxxxxxxxxx) has been set up successfully.
Initial contact regarding the telephone service…
Okay, fair enough, on the date I received that email I had only just received the ATA that I had purchased (through another supplier). Evidently they thought I had the hardware already. I found some time and quickly cobbled together a set-up:
First test set-up: siproxd on the border router to the HT814
I did some quick research, rather than doing NAT, I figured siproxd was closer to my eventual goals, so I installed that on the border router as there were fewer knobs and dials to deal with. I configured the HT814 with the settings as best I understood them from Internode’s guides with one difference: I set the Proxy field to my border router’s internal IP address.
This failed with Internode’s server giving me a 404: Not Found response when my HT814 sent its REGISTER request. I took some captures using tshark and reported this back to their helpdesk. I disconnected the ATA since there was no sense in banging on their front door every 20 seconds: it wasn’t working.
They got back to me a few days later and told me I had the right user name, and that my number still wasn’t registered. Plugging the ATA in, same response, 404: Not Found. In exasperation, I tried some changes:
Different settings on the HT814 (too many to list)
Trying with Twinkle on my laptop connected to the DMZ, both through via siproxd and also shutting down siproxd and setting up NAT.
Installing Asterisk on the border router (which was in the plans) and trying to set that up.
All three hit the same problem, 404: Not Found. I figured either I had entered the same wrong details 3 times, or it was definitely their end. So I reported that, unplugged the ATA and waited. This was on the 27th March.
On the 31st March, I get an email from Internode Provisioning to say they would be porting the number soon. After receiving this email, REGISTER worked, I was getting 200: OK in reply. Funnily enough, there was no challenge to credentials, it just saw my end and said “OK, you’re in”.
Calling outbound after this worked: the call trace showed the Internode end challenging the ATA for credentials, but once supplied, it connected the call, all worked. Inbound calls were a different matter though, a recorded (female) voice announced that the number was invalid. We were half-way there.
The next day, that message changed, it now was a recorded (male) voice announcing the number was unavailable, and offering to leave a voice-mail message. Progress. I had not changed my end, I still had T200 → HT814 → siproxd on the border router as my set-up. I was not seeing any incoming traffic being blocked by pf, although I was seeing people playing with sipvicious. I decided to firewall off my SIP ports, only exposing them to Internode’s SIP server.
Later on the help-desk got back to me. Despite their server telling me 200: OK when I sent a REGISTER, the number was still “not registered”. Confusing!
On a whim, I ripped out siproxd again and set up NAT on the border router. BINGO! We registered, and incoming calls worked. Internode use Broadsoft’s BroadWorks platform for their NodePhone VoIP service, and something about the operation of siproxd confused it. It then sent a misleading response leading my devices to think they were registered when they were not!
At this point, it was time to do two things: uninstallsiproxd, and start reading up on Asterisk.
Configuring Asterisk
Asterisk is regarded as the “swiss army knife” of VoIP. It can be configured to do a lot. Officially, it is supported on Linux i386 and AMD64 platforms, but there are builds of it for platforms such as the Raspberry Pi.
OpenBSD also build and ship it in their ports. I wanted to avoid the pain of NAT, and I also wanted to avoid the telephone service going off-line if my cluster went haywire. So installation of this on the border router was a no-brainer. Yes, it’s adding a bit more attack surface to that box, but with appropriate firewalling rules, this could be managed.
As for configuration, there were two SIP channel drivers I could use, either the old chan_sip method, or the newer res_pjsip method. I had seen guides that discussed the older method (e.g. OCAU, WP), however in the back of my mind is the question: “how long do Digium plan to keep supporting two methods?” Thus from the outset I decided to use res_pjsip.
Audio CODECs
This is a pretty big aspect of configuration and should not be skimped on. You’ll find even if you buy all your equipment from one supplier, there are differences in what audio CODECs are supported. For instance the HT814 supports the OPUS CODEC (something I’d like to take advantage of eventually) but the GXP1615 does not. Some CODECs require patent licenses (e.g. SILK, SIREN7, G.722.1, G.722.2/AMR-WB), some did require patent licenses but are now “free” (G.729, G.723.1) and some are open-source (OPUS, Speex).
Some also go by multiple names. G.711a is also called PCMA and G.711u is PCMU. Pretty much everything supports these, and depending on the country you’re in, one will be preferred over the other. In my case, G.711a is the preferred option.
Your voice provider is a factor here too. Some only support particular CODECs, some will allow any CODEC. NodePhone VoIP allegedly will allow you to use whatever you like, but calls into and out of their network to non-VoIP targets may be restricted to narrow-band CODECs.
Internode-specific gotcha: G.729
One gotcha I stumbled on the hard way was that sometimes SIP implementations do not play by the rules.
Specifically, I found once I got Asterisk installed, incoming calls would be immediately hung-up on the moment I answered. Mobile or PSTN didn’t matter. I fired up tshark again and dug into the problem. The only clue I had was this error message:
[Apr 5 16:27:40] WARNING[-1][C-00000001] channel.c: Unable to find a codec translation path: (g729) -> (alaw)
Even if I specified only use G.711a (alaw), somehow I’d still get that message. I asked about it on the Asterisk forum. I was seeing this pattern in my SIP traffic:
I was reliably informed that this was definitely against the rules. So another help-desk email informing them of the problem. If you’re an Internode NodePhone VoIP customer, and you see the above behaviour, these are your options:
If, like me, you’re running Asterisk on something else, or you despise proprietary software, there is an open-source G.729 CODEC. On OpenBSD, install the asterisk-g729 package.
Asterisk have added a work-around in later versions of their code. Patches exist for version 17, 16 and 13. It is also included in 13.32.0, 16.9.0 and 17.3.0. OpenBSD 6.7 will likely ship with a version of Asterisk that includes this work-around.
You can also complain to their help-desk. We can work-around their problem, but really, it’s their end that’s doing the wrong thing, they should fix it.
Dial Plans
The other big thing to consider is your dial-plan layout. Every SIP endpoint is assigned a context which is used in extensions.conf to determine what is meant when a particular sequence of digits is entered or how a call should be routed.
The pattern syntax is documented on their Pattern Matching page. Notably, extensions are “literal” if they do not begin with an underscore (_) and a X matches any numeric digit. So an example:
The non-pattern extensions take precedence. So the number 123456 would exactly match the first extension listed above and would call DoSomething(). The number 123987 would exactly match the second entry and would call DoSomethingDifferent(). Any other 6-digit number beginning with 123 would trigger DoSomethingElse().
Avoiding expensive mistakes
Before doing anything, it’s worth reading Asterisk’s page on Dial plan Security. You do NOT want someone to call your PBX, then dial outbound to expensive international numbers and run up a big phone bill! In particular, you want to keep the default context as lean as possible! It’s fine to put all your internal extensions in default, but anything that dials outside, should be in a separate context for internal extensions.
Dialling more than one phone at a time
It is possible to have a dial-plan entry ring multiple phones in parallel by separating the endpoints with & symbols, but don’t put spaces around the & characters! So Dial(PJSIP/ep1&PJSIP/ep2&PJSIP/ep3), not Dial(PJSIP/ep1 & PJSIP…). The most obvious use case for this is when someone rings the home number and you want all phones to ring.
Incoming calls in the dial plan
When a call comes in from outside, the number dialled by the outside party (i.e. your number) appears as the extension dialled.
A simple option is to just ring everyone… so if your phone number was, say 0735359696, you’d create a context in your extensions.conf like this:
Usually you want to be able to ring outbound too. Some guides suggested the pattern _X! can be used to “match all” but I couldn’t get this to work.
Fax over IP
I mentioned that we had a fax machine we wanted to continue using. Whilst we don’t use it every day, it’s nice to know it is there if we want to use it.
Likewise with the dial-up modem. Even if I needed to do reduced-speed for it to work, it’d be better than nothing for situations where I need to use dial-up. It’ll never connect to the Internet again, but that doesn’t make it useless.
There are two ways to do Fax over IP. One is to use G.711u and hope for the best. The other is to use T.38, where the ATA basically “spoofs” the fax modem at the remote end, decodes the symbols being sent back to digital data, encodes that in UDP packets and transmits those over the Internet. The other end then reverses the process.
The good news is there are diagnostic tools out there for testing purposes. You don’t (yet) have to know of someone who has a working fax. Here in Australia, there’s FOLDS-B.
I’d recommend if you’ve got multiple fax-capable devices though, you plug two of them into separate ports on one or more ATAs and try faxing from one extension to the other. I tried calling FOLDS-B directly at first with no luck, then tried setting up Asterisk with an extension that calls SendFax to send a TIFF image, but had no luck — handshaking would be cut short after a second.
Using two internal endpoints saved a lot of phone calls externally and allowed me to “prove” the ATA could work for this.
Once you’ve got things working locally, you’re ready to hit the outside world. You’ll need a fairly complex image to send as it needs to be transmitting for ~70 seconds. I tried a few pages (e.g. this one) on the flatbed scanner of the WF-7510 without much luck… the fax would barely muster 20 seconds of data for them even at “fine” levels.
I had better luck using the 56kbps modem and a copy of efax-gtk. I took RCA’s test card image off Wikipedia as a SVG, loaded that up into The Gimp, rendering the SVG at 600dpi, extending the image size to A4-paper sized, rotated it to portrait mode, then converted it to 1-bit-per-pixel monochrome with patterned dithering and saved it as an uncompressed TIFF.
I then passed this through tiff2ps which gave me this file:
Sending that at 14400bps took 72 seconds. Perfect! Then the reply came back. Fax reception is very much a work-in-progress, so rather than receive on the VoIP line, I decided to use the PSTN to receive the reports. This was accomplished by specifying my PSTN phone number in the fax identity (FOLDS-B evidently doesn’t check this against caller ID).
I tried again, and this time, received the report. FOLDS-B got a garbled mess apparently. The suggestion was to set the speed to 4800bps. In efax this is accomplished by setting the modem capabilities:
CAPABILITIES
The capabilities of the local hardware and software can be set using a string of 8 digits separated by commas:
vr,br,wd,ln,df,ec,bf,st
where:
vr (vertical resolution) =
0 for 98 lines per inch
1 for 196 lpi
br (bit rate) =
0 for 2400 bps
1 for 4800
2 for 7200
3 for 9600
4 for 12000 (V.17)
5 for 14400 (V.17)
So in this case, I should set the capabilities to 1,1,0,2,0,0,0,0. I tried this, but then found the call just didn’t negotiate either. On a whim again I tried 7200bps (that’s 1,2,0,2,0,0,0,0). Eureka! I got this:
A pretty much “perfect” FOLDS-B report at 7200bps.
The transmission level and SNR are pretty much spot-on. Emboldened by this, I tried again faxing the same image (which I had printed out) from the WF-7510. I chose “Photo” quality and scanned it on the flat-bed. This didn’t work so well — evidently some detail was missed and it only transmitted for 60 seconds so I tried again, and faxed something else for the second sheet.
FOLDS-B wasn’t happy about the second page, but at least it had something to go on. The fax modem in the WF-7510 doesn’t appear to have a speed control other than turning V.34 mode (33.6kbps) on/off. It appears it tried sending at 14400bps. FOLDS-B tells a sorry tale:
An ugly 14400bps transmission
Now it is possible to get near perfect results at 14400bps through an ATA that supports T.38. Maybe a longer transmission on the first page might have helped, but fair to say the speed is not helping matters.
Transmit level is very quiet, and I can’t see a way to adjust this on the WF-7510. Nor can I force it to V.29 (7200bps) mode.
There’s allegedly a “reference” test sheet you can get by “receive polling” 019725112. When I ring this number (with a fax or telephone) I get a recorded message saying the number is not valid. If anyone knows what the correct number is, or how to get a copy of this reference sheet, it’d be greatly appreciated.
So yes, Fax over IP is doable… a lot of pissing about with ATA settings… and you better hope the fax machine itself has lots of knobs and dials. Hylafax + t38modem will probably crack this nut. Then again, so will email.
Configuration Settings
Asterisk Configuration
So whilst my set-up is still a work-in-progress, I figured I’d post what I have here.
Most of these are defaults shipped with OpenBSD 6.6. Specifically of interest would be pjsip.conf and extensions.conf.
pf firewall rules
You’re going to want to pierce your firewall appropriately to expose yourself just enough for your VoIP service to work.
# Define some interfaces
internal=em0
# SIP addresses
sip_provider=203.2.134.1 # sip.internode.on.net
sip_endpoints="{ 10.0.0.3, 10.0.0.4 }"
# Allow SIP from router to SIP devices/softphones and vice versa
pass in on $internal proto udp from $sip_endpoints to self port { 5060, 10000:30000 }
pass out on $internal proto udp from self port { 5060, 10000:30000 } to $sip_endpoints
# Allow SIP from Internode to self and vice versa. This could be
# tightened up a lot further. Maybe try some calls both ways and log
# the traffic to see which specific ports. "All UDP ports" is in line
# with Internode recommendations:
# https://www.internode.on.net/support/faq/phone_and_voip/nodephone/troubleshooting_nodephone/#Do_I_have_to_open_up_any_ports_i
pass in on egress inet proto udp from $sip_provider to self
pass out on egress inet proto udp from self to $sip_provider
Grandstream HT814 settings
Some notable settings first before I dump full screenshots…
Conference Party Hangup Tone: f1=425@-15,c=600/600;
Notable fax-related settings
I changed lots of these trying to get something working, so if you set this and still don’t get any joy, check the screenshots below.
Fax Mode: T.38
Re-INVITE After Fax Tone Detected: Enabled
Jitter Buffer Type: Fixed
Jitter Buffer Length: Low (note, I can get away with this because it’s Ethernet LAN from ATA to Asterisk box)
Gain:
TX: 0dB
RX: 0dB
Disable Line Echo Canceller: Yes
Disable Network Echo Suppressor: Yes
Screenshots
Advanced Settings Page
Profile Settings
Screenshots of the HT814 settings
Grandstream GXP1615 Settings
These are much the same as the HT814 above. The cadence settings use a slightly different syntax (they don’t have the @nn parts) and there are more tone settings. Again, the ones marked with (?) have an unknown purpose.
System Ringtone: c=400/200-400/2000;
Dial Tone: f1=400,f2=425;
Second Dial Tone: f1=450,f2=425; (?)
Message Waiting: f1=525;
Ring Back Tone: f1=1209,f2=852,c=20/20-20/200;
Call-Waiting Tone: f1=425,c=20/20-20/440;
Gain: Low
Busy Tone: f1=425,c=38/38;
Reorder Tone: f1=480,f2=620,c=25/25; (?)
GXP1615 ringtone settings
The steps forward
Things I need to figure out with this system:
Feature Codes: these are used to signal events like “transferring calls”, “park”, and other features you might want to initiate in the PBX. They are normally signalled using DTMF tone sequences, however this can give problems if your tones clash with some IVR you’re interacting with. I’m currently researching this area.
OPUS support: I mentioned the HT814 supports it, and as it’s an open CODEC I’d like to support it. There is this project which provides OPUS support to Asterisk. I’ll probably look at writing an OpenBSD port for it.
Voice mail and IVR… I’m thinking something along the lines of “Dial the year of birth of the person you wish to reach”… then that can ring the relevant phones or offer to leave a message.
I’d like to test wideband audio at some point. Work seems to have G.722 on their phones (or maybe its OPUS?), I should see if wideband pass-through in fact works.
I’ve had this stuck in my head all day…one sorta has to pronounce “Corona” as “Crona” to make this work… Apologies to John Carter and The First Class…
Do you remember back in olden day, (wo-oh-oh) when everybody lived a care-free way (wo-oh-oh) whatever happened to the boy next door, now sneezing, hiding behind the bathroom wall!
Remember dancing at the high school hop The dress I ruined with the soda pop? Quarantine didn’t mean a thing Hundreds of people getting in the swing!
Corona baby, Corona baby, give me your hand let me share what I can remember Life as before we all got caught in the lock-down. Corona baby, Corona baby, you can’t understand why society was so quick to dismember. Days in the sun, to lyin’ on our bum every day!
This is just a short note… today we finally made the jump across to the NBN. We’re running hybrid-fibre coax here in The Gap, and right now the HFC NTD is running off mains power (getting that onto solar will be a future project).
I already had my OpenBSD 6.6 router running through the ADSL terminating the PPPoE link. The router itself is a PC Engines APU2, which features 3 Ethernet ports. em0 faces my DMZ and internal network. em1 is presently plugged into the ADSL modem/router, and em2 was spare.
Thus, my interface configuration looked like this:
# /etc/hostname.em0
inet 10.20.50.254 255.255.255.0
inet6 alias 2001:44b8:21ac:70f9::fe 64
# … and a stack of !route commands for the internal subnets
# /etc/hostname.em1
up
# /etc/hostname.pppoe0
# pppoedev em1: ADSL
# pppoedev vlan2: NBN
inet 0.0.0.0 255.255.255.255 NONE \
pppoedev em1 authproto chap \
authname user@example.com \
authkey mypassword up
… and of course /etc/pf.conf was configured with appropriate rules for my network. For the NBN, I read up that VLAN #2 was required, so I set up the following:
# /etc/hostname.em2
up
# /etc/hostname.vlan2
vnetid 2
parent em2
up
I then changed /etc/hostname.pppoe0 to point to vlan2 instead of em1. When the NBN NTD got installed, I tried this out… no dice, there was PADI frames being sent, but nada, nothing.
Digging around, I needed to set the transmit priority, so I amended /etc/hostname.vlan2:
# /etc/hostname.vlan2
vnetid 2
parent em2
txprio 1 # ← ADD THIS
up
Bingo! I was now seeing PPPoE traffic. However I wasn’t out of the woods, nothing behind the router was able to get to the Internet. Turns out pf needs to be told what transmit priority to use. I amended my /etc/pf.conf:
# Scrub incoming traffic
match in all scrub (no-df)
# Set pppoe0 priority
match out on $external set prio 1 # ← ADD THIS
# Block all traffic by default (paranoia)
block log all
#block all
That was sufficient to get traffic working. I’m now getting the following out of SpeedTest.
~25Mbps down / ~18Mbps up on Internode HFC NBN
The link is theoretically supposed to be 50Mbps… but whatever. The primary concern is that it didn’t suddenly drop to 0Mbps when the plug got pulled in September. I’ll check again when things are “quieter” (it’ll be peak periods now), but as far as I’m concerned, this is a matter of ensuring continued service.
It already outperforms the ADSL2+ link (which was about 15Mbps / 2Mbps). Next stop will be to port the old telephone number over, but that can wait another day!
Gotta love advertisers, they don’t bother to read or do any form of minimal research, make crass assumptions, then promptly shoot themselves in the foot:
Hello
My name is XXXXXXXX,…
Really, given it’s in your From header and your email signature, I’d have never guessed!
…and I’m a content manager at XXXXXXX XXXXXX. I’m reaching out because I came across your site and as I see you take on advertisers.
Where do you see that?
So I’m interested in purchasing some space for a sponsored article on your site.
Seriously honey, if you need to ask for a price, you can’t afford it. I bill by the nanosecond of page view time for each pixel occupied by your content.
I’m always looking for high-quality sites, like yours, so I will be glad to discuss prices and guidelines with you.
Mmm, hmm, you seriously haven’t had a very close look have you?
The content we write is always unique, relevant and informative.
As unique and informative of the load-of copy-pasta deja-moo you’ve just emailed me (in duplicate I might add)?
Moreover, we want to promote article we publish on your site. We have more than 10k subs in our email newsletter and 7k on Facebook, as you can see, we can offer not just money.
Harvesting 10000 email addresses randomly off the internet does not constitute subscriptions. Buying 7000 Facebook accounts and making them “like” your page does not constitute approval.
Ohh, and you might want to have a look at this, or this, or maybe this. Life’s too short to stuff around with a glorified BBS.
Looking forward to hearing from you.
Best regards
XXXXXXXX XXXXX
Well, you won’t hear from me directly, but you may hear from Google as you violated their terms of service in sending that spam. So yeah, I guess I do take on advertisers. I take them on and take them down.
Honest advertisers have no reason to come here, because they already have a good idea of how to build up reliable clientele without breaking laws like the Spam Act 2003 or making invalid assumptions. They do their homework. You, on the other hand, dear wannabe advertiser, are the reason such laws exist!
Updated 1 March 2020:
So, having not received a direct reply… they try again:
Just making sure you receive our last email below.
On Wednesday, February 26, 2020 at 7:30 PM, XXXXXXXX XXXXX <spammer@example.com> wrote:
${quote of original email in full}
You clearly don’t read the websites of those whom you pester do you? Actually, don’t answer that, because we know that from your original email.
So, lately I’ve been helping out with running the base at a few horse rides up at Imbil. This involves amongst other things, running three radios, a base computer, laptops, and other paraphernalia.
The whole kit needs to run off an unregulated 12V DC supply, consisting of two 105Ah AGM batteries which have solar and mains back-up. The outlet for this is a Anderson SB50 connector, fairly standard for caravans.
Catch being, this is temporary. So no permanent linkages, we need to be able to disconnect and pack everything away when not in use. One bug bear is having enough DC outlets for everything. Especially of the 30A Anderson Power Pole variety, since most of our radios use those.
The monitor for the base computer uses a cigarette lighter adapter, while the base computer itself (an Intel NUC) has a cable terminated with a 30A power pole. There’s also a WiFi router which has a micro-USB power input — thankfully the monitor’s adaptor embeds a USB power outlet, so we can run it off that.
We need two amateur radios (one for voice comms, one for packet), and a CB set for communications with the ride organisers (who are otherwise not licensed to use amateur bands). We may also see a move to commercial frequencies, so that’s potentially another radio or two.
I started thinking about ways we could make a modular power distribution system.
The thought was, if we made PDU boxes where the inlet and outlet were nice big SB50s, configured so that they would mate when the boxes were joined up, we could have a flexible PDU system where we just clip it together like Lego bricks.
This is a work in progress, but I figured I’d post what I have so far.
Power outlets on the distribution box, yet to be wired up.
I still need to do the internal wiring, but above is basically what I was thinking of. There’s room for up to 6 consumers via the 30A power pole connections along one side, each with its own 20A breaker. (The connectors are rated at 45A.)
Originally I was aiming for 6 cigarette lighter sockets, but after receiving the parts, I realised that wouldn’t fit, but two seems to work okay, and we can always make a second box and slap that on the end. Each has a 15A breaker.
Protecting the upstream power source is a 50A breaker. So total of the down-stream port + all outlets on the box itself may not exceed 50A.
The upstream and downstream ports are positioned so that boxes can just be butted up against each-other for the connectors to mate. I’ve got to fine-tune the positioning a bit, and right now the connectors are also on an angle, but this hopefully shows the concept…
The input, output, and insides so far
The idea for maintenance is the box will fold out. Not sure if the connection between all the outputs on the lid will be via a bus bar or using individual cables going to the tie point inside the box just yet. Those 30A outlets are just begging for a single cable to visit each bus-bar style. I also have to figure out how I’ll connect to the cigarette lighter sockets too.
Hopefully I’ll get this done before the next ride event.
No doubt many will have heard about the “bushfire crisis” that has basically been wreaking havoc for the past month. Here in Brisbane things haven’t been too bad, but we’ve had our fair share of smoke haze and things of course are exceptionally dry.
From where I sit, this is a situation we have let ourselves get into. Some argue that this is all because of the lack of back-burning, and to a certain extent this is true.
Back-burning doesn’t make it rain however. The lack of back-burning is a casualty of a few things, partly a lack of firefighting resources, and also significantly, a hotter, dryer climate.
Climate change has been known about for a long time. When I was growing up in the early 90s, the name used was the “greenhouse effect”. The idea being that all the “greenhouse gasses” we were generating, was causing heat to be trapped in the atmosphere like a greenhouse, and thus heating up the planet.
Back then, there didn’t seem to be any urgency to combat the problem.
So, we’ve just continued the way we always have since the start of the industrial revolution. Some things have improved, for instance electric vehicles just weren’t practical then, they are slowly gaining traction.
Large-scale PV generation in the 90s would have been seen as a joke, now we have entire paddocks dedicated to such activities. Renewable power generation is big business now. Whilst it won’t displace all traditional methods, it has an important place going forward.
Yet, in spite of all this progress, we’ve still got people in government, and in big corporate organisations who cling to the “business as usual” principle.
When South Australia announced they were going to install a big battery to help back-up their power supply, the idea was poo poohed, with many saying it wouldn’t be big enough to make a difference. What it doesn’t have in running-time, it makes up for in very fast responsiveness to load changes.
A coal-fired power station operates by using thermal energy produced by burning coal, to boil water to produce steam which drives turbines that in turn, drive electric generators. A nuclear station isn’t much different — the thermal source is the only bit that changes. Geothermal is basically using a nuclear station that mother nature has provided.
The thing all these systems have in common is rotating mass. It takes significant energy to cause a step-change in rotational speed of the turbine. If the turbine is still, you’re going to have to pump a lot of energy in, somehow, to get it spinning. If it’s spinning, it’ll take a lot of energy to stop it. Consequently, they are not known for reaction times. Cold starts for these things in the realm of a day is not unknown. They also don’t take kindly to sudden changes of load. It is during these times the emissions from such generators are at their worst.
Solar is great during the day when it’s fine, but on a cloudy day like today the output is likely to be greatly diminished, and it’ll be utterly useless at night. If we had big enough battery storage, then yes, we could theoretically capture enough during the sunny days to carry us over the nights and cloudy days. That’s a big if.
So I still see the traditional methods being a necessary evil. The combination of all three options though (renewables, traditional generation and battery storage) could be a winner. Let the older stations carry the evening base-load and keep the battery topped up, ramp them down a bit when we’re getting good renewable output, use the batteries to cover the load spikes.
Nuclear could be an option, however to my mind they have two big problems:
Public perception
Commissioning time
Without a doubt, the modern designs for these things has greatly improved on what graced the sites of Chernobyl, Three Mile Island and Fukushima. They generate waste still, but in many cases the half-life and quantity of this waste is greatly reduced. The biggest problem though is public perception, as there are many who will not differentiate between the designs, and will immediately respond: “not in my back yard!”
Even if you could win peoples’ trust, you’ve got a second problem, getting them built and commissioned in time. If we had started in the 90s, then maybe they’d be doing useful things for us now. That boat has long set sail and is dipping over the horizon now.
Transportation is another area where we’re, as a nation, addicted to fossil fuels. It’s not hard to see why though. Go outside a major capital city, and infrastructure for a purely electric vehicle disappears.
Moreover, the manufacturers, stuck in their echo-chamber, don’t see larger electric vehicles as worth the investment.
Back in 2007, my father was lucky enough to win the Multicap Art Union, and so replaced the Subaru stationwagon he’s owned since 1982 with a Holden Rodeo ute (we had the choice between that or Toyota).
This vehicle was chosen with the intent of towing a caravan with it — something he later purchased. The caravan weighs about two tonnes. Yes, an electric vehicle could theoretically tow it, and could even do a better job, but at the time, no such vehicle was available from any of the available suppliers.
To my knowledge, this is still the case. Few, if any of the electric vehicles on the market here in Australia, have the necessary facilities to tow a caravan even if the motor is capable of it.
Then there’s infrastructure to consider. A pure electric vehicle would probably be impractical outside of major regional centres and capital cities. Once you got away from the network of high-power chargers, you better plan for staying a few days in each town where you charge, because it will take that long to charge that battery from a 240V 10A socket!
Diesel-electric though, could be a winner since diesel engines similarly operate most efficiently at constant speed and could drive a generator to charge battery storage.
A return of the gas turbine engine could also be a good option. This was tried before, but suffered from the typical characteristic of turbines, they don’t like changing speed quickly. Poor throttle response is a deal-breaker when the engine is providing the traction, but it is a non-issue in a generator. They run on a wide variety of fuel types, including petroleum and diesel, so could utilise existing infrastructure, and the engines are generally simpler designs.
Is there research going into this? Not from what I’ve seen. Instead, they trot out the same old style vehicles. Many people buy them because that’s all that’s on offer that fulfils their requirements. Consequently this inflates the apparent desire for these vehicles, so the vehicle makers carry on as usual.
The lack of cycle infrastructure also pushes people into vehicles. When I do ride to work (which I’ve been trying to do more of), I find myself getting up early and getting on the road before 4:30AM to avoid being a nuisance to other road users.
In particular road users who believe: “I paid vehicle registration, therefore this road is MINE!” I needn’t waste space on that assertion, the Queensland government raised about $557M in revenue (page 14) from vehicle registration in 2018-19, whilst the DTMR’s expenditure at that time was over $6bn (page 15).
The simple truth is that a lot of these initiatives are seen as nothing but a “cost”. Some simple-minded people even say that the very concept of climate change is invented simply to slug the developed world. We need to get past this mentality.
The thing is, business as usual is costing us more. We’re paying for it big time with the impact on the climate that these emissions are having. Yes, climate does go in cycles, but what we’re experiencing now is not a cycle.
I can remember winters that got down to the low signal digits here in Brisbane. I have not experienced those sorts of conditions here for a good 15 years now. Yes, this is a land of drought and flooding rain, however, we seem to be breaking climate records that have stood longer than any of us have been alive by big margins.
The “fire season”, which is used to determine when back-burning should take place has also been lengthening. It will get to a point where there just isn’t a safe time to conduct back-burning as theoretically every day of the year will be “fire season” conditions.
This is costing us.
It will cost us with property being destroyed.
It will cost us with work being disrupted.
It will cost us with food production being threatened.
It will cost us with health issues due to increasing ambient temperatures and air pollution issues.
Lately I’ve been suffering as a result of the smoke haze that has been blowing through the Brisbane area. I recognise that it is nowhere near as bad as what Sydney has to put up with. Whilst not severely asthmatic, I have had episodes in the past and can be susceptible to bronchitis.
On one occasion, this did lead to a case of pneumonia.
About a fortnight ago I started to go down with a bout of bronchitis. I’ve had two visits to the doctor already, prescribed antibiotics and a puffer, normally by now my symptoms would be subsiding by now. This time around, that has not been the case. Whilst the previous bouts have been stress-related, I think this time it is smoke-induced.
I think once the smoke clears, I’ll recover. I am not used to this level of air pollution however, and I think if it becomes the new “normal”, it will eventually kill me. If I lived in Sydney, no question, that level probably would kill me.
This is a wake-up call. Whilst I don’t plan to join the Extinction Rebellion — as I don’t think blocking up traffic is doing anyone any favours, I do think we need to change direction on our emissions. If we carry on the way we are now, things are only going to get worse.
This is more of a brain dump for yours truly, since as a day job, I’m dealing with OpenThread a lot, and so there’s lots of little tricks out there for building it on various platforms and configurations. The following is not so much a how-to guide, but a quick brain dump of different things I’ve learned over the past year or so of messing with OpenThread.
Verbose builds
To get a print out of every invocation of the toolchain with all flags, specify V=1 on the call to make:
$ make -f examples/Makefile-${PLATFORM} …${ARGS}… V=1
Running one step at a time
To disable the parallel builds when debugging the build system, append BuildJobs=1 to your make call:
$ make -f examples/Makefile-${PLATFORM} …${ARGS}… BuildJobs=1
Building a border router NCP image
General case
$ make -f examples/Makefile-${PLATFORM} …${ARGS}… BORDER_AGENT=1 BORDER_ROUTER=1 COMMISSIONER=1 UDP_FORWARD=1
For TI CC2538
# Normal CC2538 (e.g. Zolertia Firefly)
$ make -f examples/Makefile-cc2538 BORDER_AGENT=1 BORDER_ROUTER=1 COMMISSIONER=1 UDP_FORWARD=1
# CC2538 + CC2592
$ make -f examples/Makefile-cc2538 BORDER_AGENT=1 BORDER_ROUTER=1 COMMISSIONER=1 UDP_FORWARD=1 CC2592=1
If you want to run the latter image on a WideSky Hub, you’ll need to edit examples/platform/cc2538/uart.c and comment out line 117 before compiling as it uses a simple diode for 5V to 3.3V level shifting, and this requires the internal pull-up to be enabled:
115 // rx pin
116 HWREG(IOC_UARTRXD_UART0) = IOC_PAD_IN_SEL_PA0;
117 HWREG(IOC_PA0_OVER) = IOC_OVERRIDE_DIS; // ← comment out this to allow UART RX to work
118 HWREG(GPIO_A_BASE + GPIO_O_AFSEL) |= GPIO_PIN_0;
For Nordic nRF52840
# Nordic development board (PCA10056) via J2 (near battery)
$ make -f examples/Makefile-nrf52840 BORDER_AGENT=1 BORDER_ROUTER=1 COMMISSIONER=1 UDP_FORWARD=1
# Ditto, but instead using J3 (near middle of bottom edge)
$ make -f examples/Makefile-nrf52840 BORDER_AGENT=1 BORDER_ROUTER=1 COMMISSIONER=1 UDP_FORWARD=1 USB=1
# Nordic dongle (PCA10059)
$ make -f examples/Makefile-nrf52840 BORDER_AGENT=1 BORDER_ROUTER=1 COMMISSIONER=1 UDP_FORWARD=1 USB=1 BOOTLOADER=USB
I’m working on what needs to be done for the Fanstel BT840X… watch this space.
Building certification test images
For CC2538
$ make -f examples/Makefile-cc2538 BORDER_ROUTER=1 COMMISSIONER=1 DHCP6_CLIENT=1 JOINER=1
Running CI tests outside of Travis CI
You will need:
Python 3.5 or later. 3.6 recommended.
pycryptodome (notpycrypto: if you get an AttributeError referencing AES.MODE_CCM, that’s why!
enum34 (for now… I suspect this will disappear once the Python 2.7 requirement is dropped for Android tools)
ipaddress
pexpect
The test suites work by running the POSIX ot-cli-${TYPE} (where ${TYPE} is ftd or mtd).
Running tests
From the root of the OpenThread tree:
$ make -f examples/Makefile-posix check
Making tests
The majority of the tests lurk under tests/scripts/thread-cert. Don’t be fooled by the name, lots of non-Thread tests live there.
The file node.py wraps pexpect up in an object with methods for calling the various CLI commands or waiting for things to be printed to the console.
The tests themselves are written using using the standard Python unittest framework, with setUp creating a few Node objects (node.py) and tearDown cleaning them up. The network is simulated.
The test files must be executable, and call unittest.main() after checking if the script is called directly.
Logs during the test runs
During the tests, the logs are stashed in build/${CHOST}/tests/scripts/thread-cert and will be named ${SCRIPTNAME}.log. (e.g test_coap_observe.py.log). Also present is the .pcap file (Packet dump).
Logs after the tests
The test suite will report the logs are at tests/scripts/thread-cert/test-suite.log. This is relative to the build directory… so look in build/${CHOST}/tests/scripts/thread-cert/test-suite.log.
make pretty with clang 8.0
Officially this isn’t supported, but you can “fool” OpenThread’s build system into using clang 8.0 anyway:
$ cat ~/bin/clang-format-6.0
#!/bin/bash
if [ "$1" == "--version" ]; then
echo "clang-format version 6.0"
else
clang-format "$@"
fi
Put that file in your ${PATH}, make it executable, then OpenThread will think you’ve got clang-format version 6 installed. This appears to work without ill effect, so maybe a future release of OpenThread will support it.
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