Phone numbers in Canterbury region do not start with 4 ???

Forums › Spark New Zealand (including Skinny and BigPipe) › Phone numbers in Canterbury region do not start with 4 ???

kahukowhai

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#101218 26-Apr-2012 23:01

I am writing this because I am confused about a Christchurch business whose phone number starts with a 4.

On their website www.propertymax.co.nz the use can clearly be seen of a number written as "03 4xx xxxx".

Since the 03 zone applies to the whole of the South Island the first digit of the number is generally chosen by region and the number for Canterbury is supposed to be 3. OTOH the other values are 8 for Nelson, 4 for Dunedin, 6 for Timaru, 7 for West Coast etc.

Therefore on the face of it this number would appear to be a Dunedin number even though this is a Christchurch business.

Obviously the above pattern only applies to Telecom/Chorus as 9 is used by Telstra and all other suppliers

It is very important to know if there has been a change in the way numbers are allocated because modern PBX systems don't require a caller in their premises to dial a separate number for an outside line. Instead they can dial straight out provided the number dialled doesn't match an extension number programmed into the system. Because Christchurch numbers are supposed to start with 3 then the extensions can be given numbers starting with other digits and the PBX will know the different between extensions and outside calls this way.

I know that where I work anumber that starts with 4 will be considered an extension number and therefore attempting to dial the number of this business will always be treated as an extension number therefore it is impossible to call 4xx xxxx as a local number from inside these premises.

Any ideas?

johnr

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#615781 26-Apr-2012 23:10

http://www.nad.org.nz/

kahukowhai

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#615794 27-Apr-2012 00:15

Thanks for this.

It has come as a complete surprise to me to learn that the historical rules for number range allocation, are not now followed, therefore a common sense system that is easy to determine for how the number ranges will be an invalid assumption due to Telecom having to hand over its eminently sensible system to a bunch of clueless bureacrats.

Specifically, Vodafone has been allocated ranges of numbers starting with 42X which go all over the South Island. Presumably these ranges of numbers were not previously used by Telecom in the Dunedin area and therefore alleged to be free.

Whilst it may appear attractive to do this to avoid having to upgrade the numbering system to a greater number of digits, equipment (and this is these days, modern equipment) like a PBX may conflict such a number with an internal extension number since it makes what has been hitherto an entirely valid assumption, which is that the extension numbers in the range 4xx could be assumed not to conflict with local numbers in Christchurch free calling area. This system of allocation historically was used due to the way in which exchange equipment used the successive digits to switch calls to different exchanges.

Looking through one of the documents available from that website the following blocks are being allocated to other operators for the Christchurch free calling area outside the previously valid system and which could cause problems with internal number allocations for PBX equipment of this type:

250 Two Degrees
270 Link Telecom
2710 Link Telecom
2817 Callplus
2818 Callplus
2819 Callplus
420 Vodafone
421 Vodafone
4230 Vodafone
4231 Vodafone
4239 Vodafone
5500 Orcon
5501 Orcon
5502 Orcon
5503 Orcon
590 World Exchange
667 Symbio
669 Symbio
741 World Exchange

I have omitted Telstraclear's allocations starting with 9.

As our system is programmed with internal numbers in several of these ranges these will have to be altered due to possible conflicts, or else PBX owners such as ours will have to consider requiring their users to dial a prefix for an outside line. The latter is generally avoided wherever possible these days.

There are other ranges in area 03 that have not yet been allocated but could be in the future so there is no guarantee possible that any particular range of numbers will not produce such conflicts.

sbiddle

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#615809 27-Apr-2012 06:44

kahukowhai: Thanks for this.

It has come as a complete surprise to me to learn that the historical rules for number range allocation, are not now followed, therefore a common sense system that is easy to determine for how the number ranges will be an invalid assumption due to Telecom having to hand over its eminently sensible system to a bunch of clueless bureacrats.

I disagree entirely. There is nothing wrong with the numbering ranges

You've simply got a PBX that has been programmed by somebody who quite frankly shouldn't be in the phone business if they're going to make such a poor job of programming a PBX and making assumptions on numbers ranges that proved to be incorrect.

In the analogue world predigits are pretty much a necessity, in the VoIP world they can be eliminated entirely.

cisconz

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#615830 27-Apr-2012 08:02

In the 09 region numbers starting with 7 are omitted for this reason (having your local extensions 7xx)
They must have just run out in 03.

Hmmmm

kahukowhai

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#615881 27-Apr-2012 10:01

I'm going to suggest to you that this changed model for allocating numbering ranges has not been widely publicised and is probably relatively unknown outside the telecommunication carriers.

It was not that long ago that the White Pages coverage maps for each LCA used to show the initial digits which all phone numbers in that LCA started with. As I have not read the white pages directory for years it has escaped me that this is no longer the case, the LCA maps on Telecom's website which I looked up last night do not show these leading digits any more. Obviously because of these changes.

I'd suggest the problem is the NAD has not got their heads around direct dialling functions on modern PBX systems. The direct dialling function is possible to implement on modern PBXs because they have the ability to look up the number being dialled as the keys are pressed and matching it to an internal extension number register. If an extension number is not matched the whole number is switched over to the external line.

There are still a lot of the old analogue PBXs around that have hardcoded requirement to dial a prefix for an outside line but the modern ones have this capability which relied on the previous historical precedent that has been abolished in NZ recently.

I actually don't see why different numbered ranges are allocated to specific carriers because with number portability these days the initial digits don't necessarily verify absolutely which carrier it applies to. Someone can get a number from a carrier and then change carriers and have that number ported over to the new carrier. So the initial digits only tell you which carrier initially issued the number.

cisconz

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#615898 27-Apr-2012 10:28

In our system it is smart enough to know that if I dial more than 3 digits it expects I do not want an internal extension.
Any system that doesn't is configured incorrectly.

Hmmmm

maverick

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#615908 27-Apr-2012 10:36

kahukowhai: I'm going to suggest to you that this changed model for allocating numbering ranges has not been widely publicised and is probably relatively unknown outside the telecommunication carriers.

I actually don't see why different numbered ranges are allocated to specific carriers because with number portability these days the initial digits don't necessarily verify absolutely which carrier it applies to. Someone can get a number from a carrier and then change carriers and have that number ported over to the new carrier. So the initial digits only tell you which carrier initially issued the number.

This is widely known and has been for years sorry to say for people that work in the industry, this is not new at all to PABX vendors and suppliers as it has been this way for many years if it was an issue you probably would have seen a lot of queries and post's like your previously.

Different numbers are allocated to different carries and not on as use basis as this would way to complicated and network intensive for every carrier to know every single number, numbers route to carriers based on number ranges / blocks as per the NAD allocations, the exceptions are number ports and the associated carrier HOC codes so the routing tables at each carrier whilst large could not accommodate and keep current for every single number assignment on as use basis ... incredibly impracticable,

Yes I am a employee of WxC (My Profile) ... but I do have my own opinions as well

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old3eyes

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#615987 27-Apr-2012 12:56

sbiddle:
kahukowhai: Thanks for this.

It has come as a complete surprise to me to learn that the historical rules for number range allocation, are not now followed, therefore a common sense system that is easy to determine for how the number ranges will be an invalid assumption due to Telecom having to hand over its eminently sensible system to a bunch of clueless bureacrats.

I disagree entirely. There is nothing wrong with the numbering ranges

You've simply got a PBX that has been programmed by somebody who quite frankly shouldn't be in the phone business if they're going to make such a poor job of programming a PBX and making assumptions on numbers ranges that proved to be incorrect.

In the analogue world predigits are pretty much a necessity, in the VoIP world they can be eliminated entirely.

Actually some PBX systems these day don't require you to dial an outside line access code but use conflict dialing rules. I think the Avaya is one like that. I remember replacing a Avaya in CHCH last year and they were most indignant that they had to dial a trunk access code to get to the outside world..

Regards,

Old3eyes

lxsw20

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#615999 27-Apr-2012 13:26

Correct, our Avaya system you do not need to dial for an outside line. It's one good feature!

raytaylor

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#616048 27-Apr-2012 14:40

I personally prefer to dial 1 for an outside line and will program my pbx's that i install to look at any number beginning with a 1 or a 9 to use a trunk and strip the first digit. Of course if you dial a number and it doesnt match an internal number, it will route it out a trunk anyway.

Ray Taylor

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