Configuring inbound SIP URI calls with trixbox

By Steve Biddle, in , posted: 2-Apr-2010 21:34

One of the great things about VoIP is the ability to make calls directly between VoIP phones, over the internet, without having to pay anything for the cost of the call.

Most IP phones on the market allow IP dialling direct to another phone. Many VoIP providers allow outbound SIP calling from phones to any SIP device on the internet. Some, but not all will allow inbound SIP URI calls. If you are running an IP PBX such as trixbox (or any Asterisk variant) you have the ability to accept inbound URI calls but this feature may not configured.

A SIP URI (Uniform Resource Locater) is essentially a form of  internet phone number, except it follows a SIP:name@domain or SIP:number@domain format and looks much like a cross between an email address and a website (but should not be confused with either). If you have a trixbox PBX with multiple extensions, IVR, or ringgroups, these can be called directly over the internet by another VoIP user, direct to your PBX, without having to go via the regular PSTN network or your VoIP provider. To implement this feature you need to have a static IP address for your internet connection, or be using a dynamic hostname provider such as DDNS.

Lets say your company is called Acme Phone Systems and you have the domain name of You have 3 telephone extensions and a main incoming IVR welcoming callers, and want to allow people the ability to call you via SIP URI as well as your existing PSTN phone numbers.

You could allocate the main IVR it's own SIP URI which will allow callers to connect directly over the internet without having to call your PSTN phone number. They could simply call from their IP phone and be connected directly you IP PBX. Likewise you could also allow individual extensions to be called, for example or If you wanted you could also use your existing PSTN phone number and use - the choice is up to you.

By default trixbox will not allow anonymous inbound SIP calls for security reasons. This feature is controlled by a setting "Allow Anonymous Inbound SIP Calls" which is in the General Settings menu.



Changing this to YES will automatically allow SIP URI's to work, but it's an extremely bad move. Unless you fully understand the significant security implications of enabling this it should always be set to off. Enabling this has the ability to allow unauthorised users to have access to your system and make free outbound calls if you have your system poorly configured or an insecure dialplan. When this is set to NO most inbound SIP URI calls will not be authenticated (ie they are anonymous) and will be blocked. A message saying "the number you have dialled is not in service" will be heard by the caller trying to call a SIP URI on your trixbox system.

A few simple changes need to be made to the trixbox configuration to allow inbound URI calls.

Log into your trixbox PBX and go to the PBX menu and select Config File Editor. This allows manual editing of all the Asterisk and trixbox configuration files.

  1. Click on /etc/asterisk
  2. Click on extensions.conf
  3. Click on from-sip-external
  4. Select and copy this text to your clipboard with Crtl-C

This text is the context settings called [from-sip-external] that processes all inbound SIP calls into your PBX. We can't edit this file because it's self generated by FreePBX, so we need to insert it into the extensions_override_freepbx.conf file.

As of March 2010 the content of this context is as follows, but is subject to change in future which is why it's best to use your own local copy.

;give external sip users congestion and hangup
; Yes. This is _really_ meant to be _. - I know asterisk whines about it, but
; I do know what I'm doing. This is correct.
exten => _.,1,NoOp(Received incoming SIP connection from unknown peer to ${EXTEN})
exten => _.,n,Set(DID=${IF($["${EXTEN:1:2}"=""]?s:${EXTEN})})
exten => _.,n,Goto(s,1)
exten => s,1,GotoIf($["${ALLOW_SIP_ANON}"="yes"]?from-trunk,${DID},1)
exten => s,n,Set(TIMEOUT(absolute)=15)
exten => s,n,Answer
exten => s,n,Wait(2)
exten => s,n,Playback(ss-noservice)
exten => s,n,Playtones(congestion)
exten => s,n,Congestion(5)
exten => h,1,NoOp(Hangup)
exten => i,1,NoOp(Invalid)
exten => t,1,NoOp(Timeout)


  1. Click on /etc/asterisk
  2. Click of extensions_override_freepbx.conf
  3. Paste the contents of your clipboard into the editor using Ctrl-V

The [from-sip-external] context will now be used from the extensions_override_freepbx.conf file instead of the extensions.conf file. You can now manually edit this file to allow certain inbound SIP URI destinations to pass to your Inbound Routes in the PBX menu. These can be added in the area show below ====>>>>

    ;give external sip users congestion and hangup
    ; Yes. This is _really_ meant to be _. - I know asterisk whines about it, but
    ; I do know what I'm doing. This is correct.
    exten => _.,1,NoOp(Received incoming SIP connection from unknown peer to ${EXTEN})
    exten => _.,n,Set(DID=${IF($["${EXTEN:1:2}"=""]?s:${EXTEN})})
    exten => _.,n,Goto(s,1)
    exten => s,1,GotoIf($["${ALLOW_SIP_ANON}"="yes"]?from-trunk,${DID},1)


    exten => s,n,Set(TIMEOUT(absolute)=15)
    exten => s,n,Answer
    exten => s,n,Wait(2)
    exten => s,n,Playback(ss-noservice)
    exten => s,n,Playtones(congestion)
    exten => s,n,Congestion(5)
    exten => h,1,NoOp(Hangup)
    exten => i,1,NoOp(Invalid)
    exten => t,1,NoOp(Timeout)


    A few examples:

    exten => 202,1,Goto(from-trunk,202,1)

    exten => 205,1,Goto(from-trunk,205,1)

    exten => office,1,Goto(from-trunk,office,1)


    The file will now look like this:


    ;give external sip users congestion and hangup
    ; Yes. This is _really_ meant to be _. - I know asterisk whines about it, but
    ; I do know what I'm doing. This is correct.
    exten => _.,1,NoOp(Received incoming SIP connection from unknown peer to ${EXTEN})
    exten => _.,n,Set(DID=${IF($["${EXTEN:1:2}"=""]?s:${EXTEN})})
    exten => _.,n,Goto(s,1)
    exten => s,1,GotoIf($["${ALLOW_SIP_ANON}"="yes"]?from-trunk,${DID},1)
    exten => office,1,Goto(from-trunk,office,1)
    exten => 202,1,Goto(from-trunk,202,1)
    exten => s,n,Set(TIMEOUT(absolute)=15)
    exten => s,n,Answer
    exten => s,n,Wait(2)
    exten => s,n,Playback(ss-noservice)
    exten => s,n,Playtones(congestion)
    exten => s,n,Congestion(5)
    exten => h,1,NoOp(Hangup)
    exten => i,1,NoOp(Invalid)
    exten => t,1,NoOp(Timeout)


    We now need to set up some inbound routes in the PBX, Inbound Routes menu. An inbound route needs to be created for each SIP URI that you created above. Give the Incoming route a name and in the DID field enter the number or name that you used above for the URI and set the destination. For extension 202 you would like this to go to your local extension 202. For the office you may want to set this to a ring group or IVR menu.


    image image


    Once you have these set up you're all up and running. Any inbound SIP calls to the SIP addresses you specified will now be passed through to the selected destinations!



Configuring DDI’s on WxC DVX trunks with Asterisk / trixbox

By Steve Biddle, in , posted: 25-Mar-2010 10:18

I've been a user of WxC's VFX VoIP service for a number of years now and believe they offer New Zealand's best VoIP platform for both residential and business users.

WxC offer two VoIP products in the marketplace - a residential VoIP offering called VFX and a business offering called DVX. DVX is a true SIP trunking service and offers features such as multiple inbound DDI numbers that are not available using the VFX service. I've configured VFX on numerous Asterisk systems and DVX on numerous Epygi Quadro PBX's but had never configured a DVX trunk on an Asterisk based system until I sat down last week to test a configuration.

If you're configuring multiple phone numbers with a SIP based system the easiest way is to create an individual SIP registration for each line. This defeats the purpose of a SIP trunk however and doesn't deliver a truly scalable solution - if you had 200 DDI numbers for example you would require 200 SIP registrations which is a lot of unnecessary SIP traffic. A true SIP trunking product such as the Broadsoft solution WxC offer can handle all these DDI's through a single parent registration however Asterisk needs a few tweaks to be able to handle these DDI numbers correctly.

My understanding is that people who have deployed DVX in the past have manually added additional registration lines to their sip.conf or sip_custom.conf files to forward these DDI numbers to the correct inbound route. I decided to look at a much easier way to do this that avoids requiring multiple SIP registrations and after a few minutes work came up with a new custom context that can be used as your inbound trunk in your DVX settings.


By default Asterisk can't see the DDI number - it processes it's inbound route thinking the originating number is the parent registration


Executing [91234560@from-trunk-dvx:1]


This context looks at the inbound SIP URI and extracts the DDI from the To: header and then passes this through to the regular from-trunk context that is used for inbound calls.


SIP/SPgtXt7P1OlxZDN9ao-b7c33798", "DVXDDI="User1 3bitdemo" <;rinstance=4baa739e26af491b


It can now pass this to the from-trunk context using the number 91234561 rather than 91234560


To configure this you you need to manually edit extensions_custom.conf and add the following

exten => _.,1,Noop(Extract DVX DDI/DID info from SIP URI header. By Steve Biddle
exten => _.,n,Noop(NoOp(SIP_HEADER : ${SIP_HEADER})
exten => _.,n,Set(DVXDDI=${SIP_HEADER(To)})
exten => _.,n,Set(DVXDDI=${CUT(DVXDDI,@,1)})
exten => _.,n,Set(DVXDDINAME=${CUT(DVXDDI,",1)})
exten => _.,n,Set(DVXDDI=${CUT(DVXDDI,:,2)})
exten => _.,n,Goto(from-trunk,${DVXDDI},1)


In your sip.conf or FreePBX web interface change the context=from-trunk to context=from-trunk-dvx

You can now configure these inbound routes using the DDI number and set the extension you require these to go to. This now results in a single SIP parent registration rather than multiple registrations for each DDI number.


And now a plug from me..If anybody is interested in assistance or support with Asterisk based systems or wanting help in deploying an Asterisk based PBX feel free to contact me!

I’m after a job!

By Steve Biddle, in , posted: 16-Mar-2010 10:14

If you've followed my forum posts and blog here on Geekzone over the last few months you're probably aware of the fact I've been unemployed since November after being made redundant. I decided to have a few months off over Summer relaxing (partially ruined by the fact Summer never seemed to make it to Wellington this year!) and working on a few other projects. Spending my days at the gym, socialising and catching up for coffee and lunch is a great lifestyle, but unfortunately isn't so great from a financial point of view!

To cut a long story short I'm on the lookout for another job or some more casual work in the Wellington region. Right now I have some part time projects I'm working on but I need some more challenges in life and am open to offers. . . .If you've followed me over the years you'll probably have a good idea of what interests me and where my skills lie!

I like to think I'm a bit of a guru when it comes to VoIP stuff - I've been playing with VoIP for over 5 years now have a fantastic knowledge of design and installation of IP PBX's and associated hardware. I've spent a huge amount of time playing with Asterisk and am a fan of both trixbox and Elastix. I've also worked on Epygi Quadro and 3CX PBX's and have a good knowledge of handsets and adapters from Polycom, Linksys, Snom, Aastra, Grandstream and Patton. I have a basic knowledge of Microsoft OCS and have successfully integrated my OCS setup with trixbox for external connectivity. I've also spent a lot of time playing with traditional analogue phones and PBX's and have a good knowledge of these.

I'm pretty handy when it comes to cabling work and have done numerous structured network cabling installations for phones and data in both homes and businesses. I've also installed a fair few TV aerials over the years and have a good knowledge of cabling requirements and setup of home theatre systems. I've  installed numerous CCTV and alarm systems and love electronics. Having spent time in retail I'm also pretty handy when it comes to the installation, support and best practice guidelines for EAS tagging systems.

I've been building PC's for many years and have a good knowledge of PC hardware and both Microsoft desktop and server operating systems. I'm no Linux expert but know the basics.

I'm an engineer who likes to build things, fix things, or develop innovative ideas into solutions that work. I'm not big on selling stuff but am more than capable of doing this. Cold calling is out - there is nothing that annoys me more.

I like to think I've got a pretty good understanding of the telecommunications industry in New Zealand and have a good knowledge of the various fixed line and mobile technologies used in New Zealand. I have a good understanding of both GSM and WCDMA networks and also enjoy writing about telecommunications, something you would have noticed if you've followed my blog.

I would really love to find more work in the telecommunications sector, particularly in the VoIP space as it's something I'm very passionate about. The realities however are that the market in NZ is still very much in the growing stage with plenty of cowboys who think they know their stuff trying to sell inferior solutions to gullible customers which is hurting the market. This isn't good.

If you've read my posts over the years and think I could be a good match for your company then feel free to get in touch. My contact details are listed on the right.



Telecom mobile history and Rod Deane's failing memory

By Steve Biddle, in , posted: 2-Mar-2010 14:04

In The Herald on Sunday last weekend journalist Matt Nippert wrote an article entited "Can Telecom survive" which gave a background into Telecom's mobile history and included comments from former Chief Executives Theresa Gattung and Rod Deane. Deane also also served as the board chairman of Telecom until 2006. Both have made very little comment about Telecom in recent years so it was certainly a coup to get comments from both of them. While reading this article I was interested in a comment from Deane over Telecom's choice of mobile technology:


Telecom also persisted with an older, CDMA technology for its mobile phone network and only recently upgraded to the newer industry-standard with XT.

Deane says that this, again, was the fault of Government. "We bought the GSM spectrum in an auction, and the Commerce Commission forced us to sell that back to Vodafone and Bell South. I still remember pleading with the Government that we should have that technology, but officials - in their infinite wisdom - decided against it."

Nonetheless, Deane concedes that history proved CDMA wasn't the technology of choice. "It was a bit like VHS versus Beta," he says. "And Telecom has effectively moved to VHS with XT."


These comments are completely and utterly wrong. Matt Nippert has either misquoted Deane, or Deane has a failing memory and should have probably checked his facts first before giving an interview.

Many people wonder why Telecom chose the CDMA path and didn't deploy GSM in the 1990's - the answer is quite simply that they did not own any spectrum that enabled them to deploy a GSM network.

In 1987 Telecom launched New Zealand's first mobile network using the AMPS (Advanced Mobile Phone System) technology. The AMPS standard used spectrum in the 800MHz band and consisted of two blocks of radio spectrum known as the AMPS A and AMPS B bands. These blocks consisted of an equal number of channels and were created so two networks could happily co-exist side by side. Telecom was granted usage right for the AMPS B band to deploy their network and over the next few years successfully rolled out a nationwide analogue mobile phone network. At this stage ownership of the AMPS A band was still retained by the Crown.

By 1990 network growth meant they required additional spectrum to expand their network, Telecom were already using some AMPS A frequencies under agreement with the Crown and were excited at the potential of upgrading the network to the DAMPS (Digital AMPS) standard that was ratified in March 1990. It was clear to analogue network operators already that the limited number of frequencies available would seriously hamper the grown of analogue networks and that a move to digital was essential. At this time the GSM standard was also being finalised but had still not been publically demonstrated.

In May 1990 the NZ Government announced that it was calling for public tenders for usage rights to the AMPS A band, and also the TACS A and TACS B bands. The TACS bands were European frequency blocks in the 900MHz band that were used for deployment of analogue TACS (Total Access Communication System) mobile networks in Europe, however they were now expected to be used for the GSM standard that were expected to launch in Europe in 1991. A 3rd block of TACS spectrum known as TACS C was not sold off as it was still currently in use by existing licence holders for non mobile services.

The New Zealand Government auctioned off these blocks of spectrum using the Vickrey auction process where the price paid by the successful bidder was that of the 2nd place bidder. At this auction Telecom New Zealand bid $101,200,000 for the AMPS A band but had a pay price of $11,500,000 which was the price bid by the 2nd place getter, First City (a Canadian investment bank). BellSouth won the usage rights to the TACS A network bidding $85,522,101 with a pay price of $25,200,000 that was bid by Telecom. Telecom Mobile Radio Ltd were the successful bidder for the TACS B spectrum bidding $7,000,000 but with a pay price of a mere $5000 from the 2nd place bidder, Broadcast Communications Ltd. Telecom bid for this TACS B spectrum through a subsidiary known as Telecom Mobile Radio Ltd who were at the time primarily providing land mobile radio services. They claimed this spectrum would be used for  "expanding demand for land mobile services, future mobile data services, and point to point linking services", however it was finally acknowledged that this spectrum was being acquired for future mobile services.

A condition of the auction was that any spectrum purchases by Telecom New Zealand had to be cleared by the Commerce Commission before the acquisition was finalised and submissions to the Commerce Commission were made on the 29th May 1990 seeking approval for the AMPS A and TACS B bands.

Immediately after this auction issues were raised over the fairness of Telecom New Zealand owning two new blocks of spectrum and appeals were lodged by several unsuccessful bidders. The Commerce Commission also began reviewing the case to test whether Telecom's purchase would be preventing competition in the mobile market. The Commerce Commission issued a draft determination on the 24th August 1990 saying that it believed Telecom's purchase of the AMPS A band was anti competitive and would result in it having a dominant position in the market as it would control 3 out of 4 available spectrum blocks for mobile services, as well as full control over the existing PSTN and interconnection with the PSTN. On the 17th October 1990 the Commerce Commission issued a final decision blocking Telecom from acquiring the management rights to the AMPS A band.

On the 31st October 1990 Telecom lodged an appeal against this ruling. Telecom had made it plainly clear that it's submissions that it's preference was for the AMPS A band over TACS B and that in it's view BellSouth would be competitive in the marketplace which placed even greater pressures on Telecom to acquire AMPS A. Telecom argued acquiring AMPS A "as the essential means by which it could at least achieve, first, greater efficiencies with its existing network notwithstanding its basic inferiority compared with digital technology and, secondly, the ultimate capacity to upgrade to digital technology without incurring inordinate expense and disruption of its existing analogue subscribers".

On November 30th 1990 the Commerce Commission cleared Telecom to acquire the management rights to the TACS B band, however Telecom were still so keen to acquire the AMPS A band that they reached a deal with the Commerce Commission and pledged to give up their rights to the TACS B band if they were successful on appeal for the AMPS A band, hoping that this compromise would avoid any competition issues.

Telecom's appeal was heard during a 12 day case before the Administrative Division in June and July 1991, and in December 1991 the High Court delivered a judgement dismissing the appeal. Leave was granted to appeal to the Court of Appeal which was Telecom's next step. It's also worth noting that Broadcast Communications had also filed legal action against the Commerce Commission which is part of the reason both cases took so long. In June 1992 the Court of Appeal ruled that subsequent to Section 97 of the Commerce Act 1986 Telecom should be allowed to purchase management rights for the AMPS A band. The court noted " it was not demonstrated that the grant of the AMPS-A frequency to Telecom would, or would be likely to, result in it acquiring or strengthening a dominant position in the cellular telephone market such that Telecom was entitled to clearance under s 66(7) Commerce Act 1986".

Telecom now had access to both AMPS A and AMPS B bands and BellSouth had access to TACS A. The TACS B band was subsequently sold to Telecom Australia (who later became Telstra) and remained unused. Throughout the 1990's Telecom proceeded to upgrade their mobile network to the DAMPS standard and ran their digital and analogue networks side by side.

What had become very clear to Telecom by the late 90's was the fact that GSM was vastly superior in many aspects to the DAMPS standard and had grown to become the defacto standard for mobile networks around the world. With the purchase of BellSouth by Vodafone Group and aggressive marketing that resulted, Telecom gradually began to lose market share and was faced with a network that was simply unable to offer the same capabilities as it's competitor.

Around 1999 it because clear to Telecom that they were going to need to look at options for replacing their AMPS/DAMPS network. At this stage Telecom still didn't own any 900MHz spectrum that enable it to deploy a GSM network, however 1800MHz spectrum was available that would enable Telecom to build an entirely new nationwide GSM network. The downside of the 1800MHz frequency was that it required significantly more cellsites to create a nationwide network than the lower 800MHz and 900MHz frequencies, and would also mean building a brand new network from scratch. Also being considered was the CDMA (Code Division Multiple Access) standard which was being sold as a solution for existing AMPS/DAMPS networks allowing a much simpler upgrade to something bigger and better. The base of installed AMPS and DAMPS networks in the USA was huge and this technology allowed an upgrade without having to entirely rebuild the network which would have been required with a 1800Mhz GSM network.

Telecom proceed with the CDMA network upgrade, rumours have it in part because of the much cheaper price, but also because of the influence put on the company by part owner Verizon who had already upgraded their AMPS/DAMPS network in the USA to CDMA. In 2001 Telecom launched it's CDMA network to much fanfare and the rest of the story is now well known. CDMA while technically superior to GSM in many aspects, suffered badly in the marketplace. GSM had become the dominant global cellular standard, and handset selection began to suffer as large players such as Nokia and Ericsson pulled the plug on CDMA handsets. Despite hurting Vodafone, Telecom never managed to reverse the rot that had already set it, and it became clear by around 2005 that Telecom seriously had to look at options to replace CDMA as their share of the mobile market was in decline.

Telecom's options right now were fairly straight forward, the GSM 850MHz standard had been around since 2002 and finally Telecom owned spectrum that allowed them to deploy a GSM network. Telecom also won a 3G 2100MHz licence at auction and would make use of it to build a dual mode GSM/WCDMA network that would be identical to that of Vodafone with 2100MHz 3G services in the cities and major towns and GSM coverage across the remainder of the country. The stage was set, but unfortunately things didn't run to plan.  Delays then occurred in the planning, delays which turned out to be a blessing in disguise for Telecom - the 850MHz 3G WCMDA standard had matured and Ericsson had deployed a huge 850MHz WCDMA network in Australia for Telstra. Ericsson now wanted to do the same thing for Telecom, and the decision was made to dump the GSM component and go with a nationwide 850MHz WCDMA network that would ultimately be built by Alcatel Lucent. XT was born.

What is clear is that at no time did the Government force Telecom to sell spectrum suitable for a GSM network to BellSouth/Vodafone as Deane claims. BellSouth had won management rights to the TACS A band. Telecom had won management rights to the TACS B band. Telecom simply picked the wrong horse, opting for the AMPS A band rather than the TACS B band when it was given a choice by the Government. Nobody knew at the time GSM would turn into a global standard and dominate over DAMPS - there wasn't even a single GSM network in the world in 1990 when the decision was made (the first GSM network was launched in Finland in 1991). Allowing Telecom to own 75% of the available mobile spectrum was frowned upon by the Commerce Commission in 1990 and it was a decision that was would certainly not be any different today.

So in a nutshell that's the history of Telecom mobile. A history that is unknown to many people, including the former Chief Executive and Chairman of the company!

Slingshot offer NZ's best ever mobile plan?

By Steve Biddle, in , posted: 27-Feb-2010 09:24

If you're an XT user and looked in the media today you'll see the competition are out to get your business!

Vodafone are offering to pay your early termination charges if you cancel your XT contract and are stuck with a bill for terminating this contract early. They will give you a free Nokia 6121 handset when you sign up with them.

Slingshot have also in on the act. Slingshot are MVNO (Mobile Virtual Network Operator) who piggyback on Vodafone's network. They are offering what is quite possibly NZ's best ever mobile deal.

A free Nokia 2730 handset
Free monthly access for 12 months (normally $20)
20 free calling minutes and 100 free TXT messages every month
25c calling to mobiles and landlines
12 month minimum contract

Slingshot also have a form letter quoting the CGA that you can send to Telecom explaining you would like to break your term contract and pay no fee.

If you're an XT user who is unhappy you certainly have plenty of options open to you if you do want to leave!

Telecom Exchange Tour

By Steve Biddle, in , posted: 25-Feb-2010 09:07

I had the opportunity yesterday of attending a Telecom Exchange tour hosted by Chorus & Telecom Wholesale. This included a visit to the Courtenay Place exchange here in Wellington, a look at a current Fibre To The Home (FTTH) deployment in Grenada Village and a look at a Whisper Cabinet that are currently being deployed nationwide as part of the Fibre to the Node (FTTN) cabinetisation program. It was a very interesting day with plenty to see and talk about. Since it's something many people would never get the chance to experience I took a few photos to share with everybody.


Our first stop was the Courtenay Place exchange. This is one of the two major exchanges in the Wellington CBD (the other being on Featherston Street).



Phone cable entering the exchange from the outside world



Fibre optic cable entering the exchange 



A room full of batteries in case of a power cut



And backup generator. There are two of these required to power the exchange.


P1030159 P1030161

P1030164 P1030162


A view of the MDF (main distribution frame) in the exchange and some close up photos of the different types of connections - ranging from the old solder type to more modern punch down blocks. The frame contains a "D" side and an "E" side - one is from the outside world and the other is from the NEAX switch. A cable is patched between both sides of the frame to provide service.



The fibre section of the exchange. Fibre enters the exchange and has to be patched in much the same way copper is.



Inside of a cable trays where the fibre is joined.




The Alcatel Lucent 7302 ISAM that provides ADSL/ADSL2+ broadband services from this exchange. This is the same hardware that is deployed in the new roadside cabinets.


P1030154 P1030157

Orcon and TelstraClear equipment in the exchange. Both provide ULL (Unbundled Local Loop) internet and voice services from this exchange.



Next up was a visit to Grenada Village to visit the single FTTH deployment in Wellington. This deployment uses the GPON (Gigabit Passive Optical Network) standard. This deployment is in a new subdivision that currently only has a handful of active customers and there are approximately another dozen houses under construction at present. This cabinet is what is known as a "passive cabinet" - it does not require any power to operate. It is simply splitting the incoming fibre and acting as a simple patch panel. This cabinet has capacity for up to 288 houses.


In the photo above you can see the the yellow fibre that runs from each house back to the cabinet. The fibre at the top is currently unconnected.



The optical splitter (essentially just a glass prism) splits a single optical signal across 32 outputs. There is capacity in this cabinet for 9 splitters but only a single splitter is fitted at present due to the small number of customers.






The fibre then enters the tray where it is "patched in" and connected to liven up the connection to the house.



The underground pit where fibre from the exchange is connected to the cabinet. Spare fibre is available so the installation is future proofed.



There is no copper cabling deployed in this subdivision, every household requires a ONT (Optical Network Terminal) which turns the optical signal back to an electrical signal. The ONT provides a standard Ethernet output which connects to a router to provide internet access. The phone service is VoIP (Voice over Internet Protocol) and customers have the option of using VoIP handsets in their house or connecting regular analogue phones to an ATA (analogue telephone adapter) that converts the VoIP service to analogue. At present all internet and voice services are provided through WorldxChange Communications as Telecom Retail do not currently have a residential VoIP product in the marketplace.


The picture above shows a mock-up of the hardware that is typically being fitted in the home at present. This includes a Linksys router with built in ATA that allows you to connect analogue phones. It also includes a battery backup to ensure that phone service is still available in the case of a power cut.



Next up was a site visit to a working Chorus FTTN cabinet. These cabinets are brand new state of the art technology that are being deployed nationwide as part of the Chorus cabinetisation rollout. Approximately 1500 have currently been deployed nationwide out of a total of 3400, with the project due for completion towards the end of 2011. ADSL (and the forthcoming VDSL) deliver faster speeds the closer the customer is to the cabinet or exchange - because the customer can't be moved closer to the exchange the solution is to build these cabinets and move the hardware closer to the customer. These cabinets are connected back to a local exchange by fibre and copper, the fibre is used for backhaul for internet services and the copper is used to provide voice service from the existing NEAX switch in the exchange



Inside of the cabinet. On the left is the Alcatel Lucent 7302 ISAM that provides ADSL/ADSL2+ broadband. On the right is the MDF (main distribution frame) which contains copper cabling from the local exchange and from each nearby house or business. These are jumpered together to provide voice and broadband service to customers.



A close up look at the ISAM and cards


These cabinets were designed and built in New Zealand by Eaton in Christchurch and each cabinet is designed to serve to up approximately 300 customers. At present they only contain Telecom equipment but the space on the left is available for other telecommunications providers or ISP's to install their own equipment if required. As mentioned above all voice services are still provided by the existing phone exchange, however it is possible that in the future Telecom could install hardware in these cabinets to deliver voice services when the NEAX switches are retired. A voice card for the existing Alcatel Lucent ISAM could easily be installed and would connect to Telecom's core network using VoIP but would convert this to analogue so that existing phones in your home or business would continue to work as normal. The cabinets have a battery bank to ensure they work even during a power cut, and can be powered by a generator if need be during a prolonged outage.


A special thanks has to go to Chorus and Telecom Wholesale for organising such a great afternoon!

Is the MTR saga over?

By Steve Biddle, in , posted: 23-Feb-2010 10:48

Yesterday was an interesting day in the mobile world in New Zealand. Along with yet another outage affecting the XT network, the Commerce Commission submitted their findings to the Communications Minister in relation to Mobile Termination Rates (MTR). The Commission in a 2 to 1 majority recommended to Communications Minister Steven Joyce that an aligned undertaking from both Telecom and Vodafone be accepted rather than the Commission being forced to intervene in the market and force the regulation of wholesale interconnection pricing.


The response from those with opposing viewpoints was interesting

                2degrees said

Today is a very disappointing day for New Zealand mobile users. After much delay, the Commerce Commission appears to have squandered a golden opportunity to finally bring New Zealand mobile prices into line with the rest of the developed world. New Zealand consumers suffer with some of the highest mobile prices in the world. The Commission’s recommendation to leave the decision on access pricing up to the incumbents, Vodafone and Telecom, will mean this burden on New Zealanders continues for the foreseeable future.


The response from 2degrees was as expected. They are a company that has spent most of the last decade complaining about the regulatory environment in New Zealand rather than getting on with building a network. In August last year 2degrees finally launched their network and by their own admissions are doing amazingly well. Last week they announced that they had signed up 206,000 active customers, a figure that was well ahead of expectations, and also announced that for the first time people in New Zealand are now able to access prepaid calling rates at prices well below the OECD average. They are also claiming ARPU (average revenue per user) in excess of $10, a figure that is higher than many Telecom prepaid customers.

The question has to be asked as to why 2degrees seem to have significant issues with the Commerce Commission decision. Right now their business is booming and yet they see regulation of the industry as being essential to compete. One really has to wonder why this is the case.

The Drop the rate, mate! Lobby group (that is heavily backed by 2degrees and several unions) went even further accusing Commerce Commission members of doing “an about face”


Two members of the Commerce Commission have done an about-face, after repeated voluntary undertakings from the big telcos – while another, Anita Mazzoleni, has sided with consumers, the Drop the Rate, Mate! campaign said today.


The Drop the Rate, Mate! Campaign was formed to “to demand lower mobile termination rates in line with the costs of connecting calls and texts”. They have never explicitly explained exactly what they mean by this statement and where they see pricing in the market, but when a campaign is powered by nothing but hot air this isn’t surprising. One would presume they would be at least partly happy with the Commission’s announcement, SMS rates are potentially going to be cut to under cost and voice revenue cut to levels that are in line with costs based on some pricing models. Exactly what “about face” they are talking about is unknown, for months now the Commerce Commission have been actively encouraging a joint aligned undertaking from all three carriers that would deliver pricing that was acceptable to the Commission in preference to the Commission forcing regulation of pricing. To say that two members of the Commerce Commission have done an “about face” and no longer care about consumers is nothing but rubbish. The only “about face” I’m aware of in the whole MTR saga was the decision in December by 2degrees to throw their toys out of the cot and withdraw all previous undertakings that they had submitted to the Commerce Commission leaving them with no offer on the table.

I’ve been accused of working for both Vodafone and Telecom in past blog posts on the MTR issue but want to make it perfectly clear I no ties with either company. The telecommunications sector as a whole is of great interest to me and watching the MTR saga drag out over the past year has been fascinating. The rates charged by some carriers in New Zealand for fixed line to mobile and for mobile to mobile calls are expensive, what people need to remember however is that the MTR issue is a discussion of pricing of wholesale traffic interconnection, it isn’t a discussion on retail pricing. The Commerce Commission have no plans to regulate retail pricing and believe that pricing will fall due to competition in the marketplace due to lower termination rates. Whether this occurs is still to be seen as there is no evidence anywhere in the world that can draw any established relationships between wholesale interconnection rates and retail pricing. There are countries with high interconnection rates and low calling costs and countries with low interconnection rates and high calling costs.


What offer is on the table?

Both Telecom and Vodafone have said that from the 1st October 2010 they will drop SMS interconnection pricing to 0c and adopt a hybrid Bill and Keep pricing model. This hybrid pricing model means that Vodafone and Telecom will not charge each other for delivering SMS messages to the other network providing traffic levels remain even. If an imbalance in traffic occurs at a level between 7% and 12% then a charge of 2c per message will apply, and for an imbalance of greater than 12% a 4c per message charge will apply. The reason for the hybrid system and not a true bill and keep solution is primarily at attempt to stop the proliferation of unsolicited SMS messages, in a true BAK model with no restrictions it’s possible for a network to actively sign up users whose only intention is to deliver unsolicited SMS messages to users on other networks. It’s worth noting that current SMS traffic levels between networks are all reasonably even as SMS is a two way medium – if somebody sends you a SMS, move often than not you will send a reply.

Both networks will drop voice interconnection rates for mobile to mobile and fixed line to mobile to 12c per minute from the 1st October 2010, with theis rate following a glide path dropping on the 1st January every year until it reaches 6c per minute on the 1st January 2014. All interconnection costs will be billed per second.

So what did 2degrees want?

2degrees have been pushing for rates to go even lower. Their last undertaking was for a true BAK pricing model for SMS messages (ie no charge even if there was a traffic imbalance), and for voice interconnection rates to be approximately ½ of what both Vodafone and Telecom submitted in their undertakings. Many of their submissions did nothing but complain about the competition rather than offer reasonable solutions and from the outside it seemed like their purpose was to hijack the whole investigation solely for their own motives.

2degrees have a true motive – and that’s the introduction of a true BAK pricing model for mobile in New Zealand. As a newcomer to the market they have the most to gain from BAK – the majority of calls from 2degrees mobile users are off net, this results in 2degrees having to pay Vodafone or Telecom money to interconnect calls. Likewise because the number of inbound calls falls well short they end up in a situation where they are paying other operators more than they are receiving in termination costs. It’s easy to see why 2degrees want BAK, the problem here is that the Commerce Commission were not interested in looking at using BAK as a pricing model for New Zealand. No other country has moved from a CPP (calling party pays) to BAK pricing model for mobile, and such as a move was totally out of scope for the MTR investigation. Exactly what decision 2degrees make now is over to them – they presumably still have the option of joining Vodafone and Telecom and leveraging their agreement, continuing with their current interconnection agreements, or sitting on the sideline with their ratchet making lots of noise while contributing very little.


Right now you have a choice in New Zealand when it comes to mobile. With three networks and a myriad of pricing plans there is plenty to choose from. What is plainly clear is that the wholesale cost of interconnection plays a minor part in determining the retail cost of both fixed to mobile and mobile to mobile calling. It’s possible to pay 23c + GST per minute to call a mobile phone from a Telecom Business line however a Telecom homeline user with no calling plan will pay 63c incl GST for the same call. Up until several years ago the standard Telecom rate for fixed to mobile was 71c per minute, a rate that was set close to 20 years ago when the MTR rate was around 50c per minute. We’ve seen wholesale MTR costs fall by more than 60% in that time but the standard retail price fell by approximately 10%. Likewise a mobile user can currently be paying as low as 25c + GST per minute with per second rounding after the first minute for a voice call using a provider such as Compass Mobile (a MVNO on Vodafone’s network) or can be paying 89c incl GST with calls rounded up to the next minute if you’re on Vodafone Prepay.

It’s very clear that wholesale MTR costs are not the cause of high mobile pricing in New Zealand, the problem is one of retail pricing. As MTR costs have fallen over time retail costs have not necessarily followed due to a lack of true competition between the two mobile operators in New Zealand. The Commerce Commission investigation had good cause and the current offerings on the table from both Telecom and Vodafone will mean significant drops in inbound revenue for both operators. As to whether it will mean cheaper calling prices for New Zealand mobile users is another question entirely, something only time will answer.

Mail For Exchange 3.0 for Nokia delivers HTML and folder support

By Steve Biddle, in , posted: 14-Feb-2010 20:35

If you are a Nokia phone user and use a Microsoft Exchange based email solution odds are you use MfE (Mail for Exchange) for your email. Newer Nokia handsets use Nokia Messaging, but for the large majority of users out there MfE is the only option as the standalone Nokia Messaging application does not support Microsoft Exchange.

For many years MfE has been severly limited with two major contraints - lack of folder support and no support for HTML, two features that were serious downfalls for devices such as the E71 that were targeted at email users.

The good news is that in recent days Nokia have released a brand new V3.0 release of Mail for Exchange. Included in the release is support for both HTML and support for folders in your inbox.

There is still no mention of this software of the official MfE website but it's available for download from Ovi Store.

I've been running this on my E71 for the last few hours and while it's still not a perfect solution it's finally great to be able to have access to features that should have been part of the software many years ago!

EDIT: There have been numerous people comment and also contact me saying that they can't find the HTML option. I can assure you that HTML viewing IS THERE!!!

If you have an HTML email click on options and there is a menu item saying view as HTML.

TV1 and TV3 6PM News Ultimate Maths Fail

By Steve Biddle, in , posted: 9-Feb-2010 19:14

If you were (un)lucky enough to watch TV1 or TV3's 6PM news broadcasts tonight you were witness to a classic maths failure from both networks - the inability to correctly calculate a proposed 2.5% increase in GST.

Both networks showed a list of prices and calculated the new price with a 15% GST. Both failed miserably when it came to such a simple calculation and have no doubt confused an entire country.

When a product sells for $1500 the GST component of that price is $166.66 (rounded to 2 decimal places) and the GST excl price of the product is $1333.33 (rouded to 2 decimal places).

To deduct GST from a price divide it by 9 to establish the GST value or divide it by 1.125 to establish the GST exclusive amount,

Both networks simply added 2.5% onto the existing GST inclusive price which is wrong and does not give the correct amount. To calculate the new 15% GST inclusive price, the current 12.5% GST needs to be deducted from the current retail and the new 15% GST rate added to this GST excl price.

On TV3's example of a $1500 TV they show the new price of $1537.50, a $37.50 increase. 15% GST on the GST excl price of $1333.33 is $200.00, giving a new retail of $1533.33, a $33.33 increase.

On TV3

$1.50 is a only a negligible difference due to rounding
$200 -> $205 when it should be $204.44
$1500 -> $1537.50 when it should be $1533.33

How can you trust either network to deliver is accurate news when they're unable to calculate a basic maths equation?

What will fibre and ultra-fast broadband mean for you?

By Steve Biddle, in , posted: 2-Feb-2010 12:50

When the National Government was elected in 2008 one of its pledges was to roll out ultra-fast broadband to New Zealanders. A promise of $1.5 billion was put on the table to be spent over six years delivering fibre to a significant number of New Zealand households and businesses.

To quote from the Ministry of Economic Development

Overview of the initiative

The government will be investing up to $1.5 billion in open-access, dark-fibre infrastructure to accelerate the roll-out of ultra-fast broadband to 75 percent of New Zealanders over ten years.

Ultra-fast broadband is defined as a fibre-to-the-premise broadband service providing downlink speeds of at least 100 Mbps and uplink speeds of at least 50 Mbps.

The government themselves will not necessarily be owning or operating a network – their plan is to partner with private companies who will build open access networks that can be accessed by wholesale and retail providers who wish to provide services. These networks do not need to be nationwide and it was envisaged that several different providers would pay a part in building individual networks that would ultimately all be connected.

In October 2009 Communications Minister Steven Joyce announced the formation of Crown Fibre Holdings. Their role is to assess the submissions for networks, invest the Government's money, and monitor performance of these networks. An invitation to participate was issued in October 2009 and when submissions closed at the end of January 33 proposals from 18 respondents had been received, two of which were for nationwide networks.

The announcement is not going to result in every household in New Zealand suddenly being connectable to a fibre optic network immediately, the priority in the first six years is on delivering services to schools, businesses and health providers.


So what do we have right now?

Right now New Zealand is in the middle is in the middle of a huge network expansion by Telecom New Zealand to deploy a fibre to the node (FTTN) network. Broadband speeds over copper are dictated primarily by the length of the copper cabling from the exchange to the premises. ADSL and VDSL signals don't travel well over long distances so by shortening the length of copper cabling (the "copper loop") to the premises broadband users will see increased broadband speeds. The goal is to deliver speeds of between 10Mbps and 20Mbps to 80% of New Zealanders by the end of 2011.

Chorus are achieving this by installing 3600 roadside cabinets around New Zealand and connecting the vast majority of these cabinets back to their existing network with fibre optic cable. Most cabinets will service in the vicinity of 300 customers who will typically be no further than 2km away from a cabinet. By installing an ISAM (the piece of hardware that generates the ADSL or VDSL signals) to this roadside cabinet (the "node") it will ensure that customers receive significantly faster broadband speeds. Customers who are beyond 2km from an exchange or cabinet will see speeds drop significantly and there are no simple cost effective ways of delivering them faster speeds using this technology.

Telecom are currently offering either ADSL or ADSL2+ broadband from their exchanges and cabinets with trials of VDSL2 underway. Unlike ADSL or ADSL2+, VDSL2 uses additional frequencies to offer even faster speeds. Vodafone and TelstraClear are also either trialling or offering VDSL2 services in some areas. ADSL2+ has the ability to offer speeds of up to 24Mbps, VDSL2 has the ability of offering speeds of up to 100Mbps for both downstream and upstream connections. Like ADSL, speeds taper off quickly and a customer who's located 1km from an exchange or roadside cabinet could expect to see downstream speeds in the vicinity of 35Mbps – 50Mbps and upload speeds in the vicinity of 7.5Mbps to 10Mbps.

Voice services are still currently provided from Telecom's legacy NEAX exchanges. In the future these NEAX exchanges will be made redundant and replaced with either hardware providing voice services from the cabinet or by the installation of residential gateways in households to provide a VoIP service over a broadband connection, the same solution that is used for fibre.



If you're located in Wellington, Christchurch, the Kapiti Coast or Hutt Valley you also have access to TelstraClear's Hyrid Fibre-Coaxial (HFC) network that has a similar FTTN architecture. Fibre is run to roadside cabinets but instead of using existing copper phone cable for delivering services to the home, coaxial cable is run from the cabinet to the household for broadband and cable TV services. TelstraClear are currently in the process of upgrading their network to support the DOCSIS3 cable modem standard that will deliver speeds of up to 100Mbps downstream to customers in the near future. DOCSIS3 features a capability known as channel bonding that allows up to 8 downstream carriers to be joined together and speeds of up to 300Mbps downstream and 120Mbps upstream have been demonstrated on live networks. One significant advantage of the HFC network over copper is that speeds are not affected by cable lengths, a customer who's located anywhere within a TelstraClear node will receive the same speeds as any other user.


What does fibre do better?

Quite simply, fibre is capable of delivering far greater speeds than can be delivered over copper. Speeds are also unaffected by cable lengths as is the case with ADSL or VDSL. Fibre distribution for broadband is not new and has been common in countries such as Japan for many years, the key difference between Japan and many other countries such as New Zealand is that many people live in apartment buildings and the cost of deploying fibre to a single building with a large number of customers has made economic sense. The rollout of fibre has greatly increased over the past couple of years with the introduction of the GPON (Gigabit Passive Optical Network) standard which has reduced the complexities of network layouts and delivered significant performance gains over earlier standards. The GPON standard has seen huge growth and has been chosen by a large number of providers around the world. One of the fastest growing GPON networks at present is the Verizon FiOS network in the USA which currently has availability in 12.7 million homes and over 3 million customers. GPON has already been deployed in New Zealand by Chorus and is in use in several new subdivisions where residents are already receiving their broadband and phone service over fibre.


How does it work?

The key part of a fibre network is an Optical Network Terminal (ONT) which converts the optical signals to electrical signals. The fibre optic cable plugs into the ONT, which then converts the signal to Ethernet which can then connect to a standard router. Since fibre is incapable of carrying voice calls like a regular copper phone line, voice traffic is Voice over Internet Protocol (VoIP) so if you wish to continue to use traditional analogue phones you'll need an analogue telephone adapter (ATA) to connect your phones to the VoIP provider. This ATA can either be built into the ONT, your router, or be a standalone device. With the large number of standalone VoIP phones in the market these days customers also have the option of moving away from analogue phones entirely and taking advantage of the added benefits a true VoIP handset can offer.


Figure1 - Hardware Used in a typical Telecom New Zealand GPON Installation. This consists of an Alcatel Lucent ONT, a Linksys Router featuring a built in ATA for analogue phones, and a patch panel connected to RJ45 data sockets throughout the house for all data and analogue phones.




Figure 2 – Examples of Polycom & Linksys VoIP phones. All can replace existing analogue phones



The most significant downside of fibre over copper is that if you suffer a prolonged power outage you run the risk of having no broadband or phone services. The hardware installed in your premises requires power to operate, and even though it will be fitted with a battery backup solution this can't last forever.

VoIP also doesn't support dialup modems, alarm diallers or devices that may contain embedded modems such as medical alarms or MySky boxes. In all these cases alternative solutions need to be found. Monitoring alarm systems can easily be done over IP with a monitoring company who supports this service and existing alarms can easily be adapted to run over an IP connection.


What are the downsides?

The biggest downside of fibre is the cost. With a copper based broadband and phone service you simply plug your analogue phones and ADSL modem into regular phone jack point in your house. With fibre things aren't quite so simple and DIY installs will be a thing of the past. A significant amount of hardware needs to be professionally installed in your house to provide you with internet and phone services, for an average household this could end up being in the vicinity of $1000, a cost that will certainly have to be paid by the end consumer in one way or another at the end of the day, whether it is through installation charges or term contracts with an ISP. To take full advantage of new generation services that can be delivered over fibre a structured cabling solution in your house becomes vital, the cost of upgrading cabling in an existing house is something many homeowners may have great issues with. Telecom have recommended since the late 90's that all new households have a structured cabling system with cat5e and RG6 coax cable but it's something that many architects, builders, electricians and homeowners have chosen to ignore even though it adds very little to the cost of a new house.


How much will fibre cost? Do I really need it?

Fibre isn't the answer to everything. Add in the significant costs of installation hardware and many people may see no compelling reason to upgrade. New Zealand still suffers from low broadband data caps and significant costs in bringing data to our tiny little country from elsewhere in the world. Having a 100Mbps internet connection with a paltry 20GB cap isn't going to give people a compelling reason to switch! It's also worth remembering that much like busy motorways there will always be areas of congestion on the internet, and in reality speeds that may be delivered over fibre for general web surfing and downloads may not be significantly faster that over existing connectivity options. The ability to deliver high definition video to people's houses may sound great, but it's still going to come at a cost and won't necessarily deliver content that's not currently available elsewhere in New Zealand.

Fibre is capable of delivering significant benefits over the FTTN network currently being deployed by Chorus. The big 'if' is whether fibre is going to offer enough compelling reasons for people to upgrade. A nationwide fibre rollout is going to cost billions of dollars, and while it may deliver better internet it's certainly not going to deliver cheaper internet. It's my belief that the government should also be investing in international connectivity to connect us to the world – having world class internet is going to be no good if people are unable to afford it.



sbiddle's profile

Steve Biddle
New Zealand

I'm an engineer who loves building solutions to solve problems.

I also love sharing my views and analysis of the tech world on this blog, along with the odd story about aviation and the travel industry.

My interests and skillset include:

*VoIP (Voice over IP). I work with various brands of hardware and PBX's on a daily basis
  -Asterisk (incl PiaF, FreePBX, Elastix)

  -xDSL deployments

*Structured cabling
  -Home/office cabling
  -Phone & Data

*Computer networking
  -Mikrotik hardware
  -WAN/LAN solutions

*Wireless solutions
  -Motel/Hotel hotspot deployments
  -Outdoor wireless deployments, both small and large scale
  -Temporary wireless deployments
*CCTV solutions
  -Analogue and IP

I'm an #avgeek who loves to travel the world (preferably in seat 1A) and stay in nice hotels.

+My views do no represent my employer. I'm sure they'll be happy to give their own if you ask them.

You can contact me here or by email at