Appreciate some advice with the planning of some office comms.

We run an office in Auckland and Wellington and have operations spread between these i.e. customers call each location directly.

We are merging part of our operation into Auckland and will need to get Wellington calls to Auckland (and vice versa) in the most cost effective way possible. We want the option to be able to pass calls between the centres and also support each other if required.

Our operations run 24x7 and we require a good quality phone service for customers. I have experienced very noisy and latent VOIP connections so not sure if this is the solution?

We currently utilise an AVAYA IP phone system in Auckland and have an old PABX in Wellington.

An outcome we would like to have is the ability for customers in each centre to 'appear' as though they are being called from the local office if in fact the call is being made from elsewhere.

I understand that we could get the respective number call forwarded to the other however this will cost each time and so really looking for some advice to either products or services out there that can assist.

Appreciate any advice to steer me in the right direction.

Thanks