1. Home
  2. Telecom Technical
  3. VOIP / SIP gateway in New Zealand?

VOIP / SIP gateway in New Zealand?

.. pls help me get my head around this.

Business has a 12 month old NEC IPS 2000 PABX with voip capability (use IP cards for trunk to trunk calling over frame relay to remote office with same NEC PABX model, also use NEC softphones successfully). GM now asking for us to set up the existing NEC IPS to utilise Voip calls in addition to PSTN calls to overseas customers and suppliers as a cheaper alternative.

So I figure we need these 3 things:

  1. A decent internet feed - Tick, we have 5mbit Ethernet feed.
  2. Some sort of hardware gateway to talk to a VOIP provider (where do I start? Cisco?)
  3. A VOIP provider that bills us for calls at less than the local Telco.

Am I on the right track here? Does such a VOIP provider exist down here in NZ? Could I use overseas prov instead? How do callers make VOIP calls back to you (e.g a staff member being contactable at their desk phone via a Voip address just like using a DDI?) Phone system wise how would the NEC phone system determine routing of calls via VOIP vs PSTN.

Sorry for all the questions, newbie to this. Want to get my head around principles before going any further. Technology assumptions tend to cost money :-)

Reply to
smooter.guy
Loading thread data ...

Poke around on this page. There are two business-to-business voip companies listed under NZ. Probably there are a few multi-regional ones too.

formatting link

If you want calls from the PSTN sent to you over VOIP, the easiest way is to have a voip provider get you a set of DIDs. They will then route calls made to those DIDS to your sip equipment.

Conventional wisdom is that you don't really want to do this in a business setting. Voip is less reliable than direct PSTN connections and you don't want to lose any incoming customer calls. The conservative answer is use PRI trunking for incoming calls and use voip for outgoing. If the outgoing voip is down, roll the outgoing calls over to the PRI.

There are a few proposals that attempt to make it easier for companies with sip-capable pbx's to call each other without going through the PSTN, but that is still in its infancy. The one that, to me at least, seems to have the feature set is called ISN. One dials a two-part phone number with an embedded "*" as separator. One number identifies the company, the other part is the internal phone number. The beauty of this scheme is that there is no need to have a DID per phone for this type of dialing. The intro page is at

formatting link
. It seems to work, I've used it, the problem is, very few organizations have registered their sip servers so there just isn't much to call yet.

Sorry, I'm only familiar with "homebrew" systems like asterisk. In asterisk case one writes a ordered small list of what the system is supposed to do when it gets a call. For outgoing calls one normally has it try to route to the voip provider first, then a fallback voip provider if one has one, then a direct PSTN line.

You might also find it interesting to poke around the top-level pages of the following URL. It has some good background info, but the indexing / searching could be better.

formatting link

-wolfgang

Reply to
Wolfgang S. Rupprecht

Cabling-Design.com Forums website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.