Consider these questions :
- Do we make money over the phone?
- Do we need 100% reachability for our customers?
- Is there enough IP bandwith available at a reasonable cost?
- Do we expect to grow as a company in the near future?
- Do we
really need features like
Presence
Unified Communications
remote/home workers
road warriors
- Make a
TCO calculation on both solutions
What are the total first time costs (installation, hardware etc. )
What are the yearly costs to keep it operational ( service contract, power usage etc. )
What are the costs for changes/migration/expansion ( changing names, swapping users around etc., extra lines/phones etc)
- Consider the partners to contract
Are they reliable partners ( how long are they in business, what is their core business ( IT or Telephony ))
Do they have references ( can you talk/visit their references )
Can they respond in a reasonable time in cases of system disruptions ( enough qualified personnel )
And there may be a lot more considerations to make, depending on your organisation.
I would base my choice on questions like the above and then decide which route to follow and make a technical decision what brand to buy ( of course we recommend
Avaya IP Office ) but there are a lot more options as only Avaya to consider. If you don't need any of the above features then you may be better off with a hm
Panasonic or
SIEMENS system (cheaper and reliable too but less state of the art techology and thus lack of features ).