Your salesman may not address issues that are not brought up to you, therefore it is YOUR responsibility to do as much research as possible before you sit down for a conversation with a salesman. On the other hand, without doing your own research you may feel that the salesman may be trying to upsell you if he brings up something that you did not address to him.
If you already have a legacy PBX you may consider getting an analog adapter to provide VoIP lines to your existing PBX system. This should provide you the fastest way to move over to a VoIP provider, however you will be using your existing phone system to handle call routing, and like traditional POTS phone service you will be limited with the amount of calls based on the amount of lines you order from your provider. This is the cheapest method to get VoIP to your business, and it also will allow you to maintain your existing auxiliary systems connected to your phone system, such as your existing door phones, overhead paging system, music on hold, etc. In the event of an outage your provider may be able to automatically have your lines forwarded.
Another option you may consider is having a VoIP server installed in your office in your network room, and have your VoIP phones connect thru this system. With this method you would pay your provider for however many channels that you expect to use. Depending on how your PBX is configured you may be able to connect IP phones off site, but all management would be accomplished from the server located on your premises. While this may save you some money over a hosted solution for your recurring charges, the upfront costs of the additional hardware required (the server) and the configuration would increase your initial costs. This method would really only be recommended for companies that have an IT department that can manage and maintain the VoIP server. In the event of an outage your provider might be able to have your lines forwarded, however since your server is located on site callers would not hear your IVR menus.
The most common, and in my opinion the best choice when moving to a VoIP platform would be to go with a hosted PBX provider. The only thing located on your site would be the phones which would communicate over the network to the providers servers directly. This allows phones to be located anywhere on the internet without and additional configuration (normally). The provider is responsible for maintaining the VoIP server, as it is located in their datacenter. In the event of an outage your provider will be able to forward your lines, your callers will still hear your IVR menu just as if your system never went down, and calls can actually be forwarded to different numbers based on the extensions that were dialed.
Now that you have a better understanding of the different VoIP choices that you have, now you should consider what other systems work with your phone system. If you have or need a door phone, overhead paging, or even some custom hardware or software that needs to be integrated into your phone system - you should really consider a provider that has a physical presence with technicians local to where you intend to operate. Many of the cloud only phone providers will only be able to provide you with your telephone service needs, and not have any ability to provide more complex configurations or system integrations.
An example of a custom integration would be one of our customers has a system where their customers take a number and they wanted that integrated into their phone system so that people could call in to see what number they were up to. This is not a feature that we had ever provided to any other customer before, but with collaboration with our in house programmers, and on-site technicians within a week we had a solution for that customer and was able to implement it to the customers satisfaction. Had that customer chosen a provider that did not have a local physical presence with field techs this feature would have never been possible for this customer.
Moving onto wiring requirements. It is recommended that there is a separate CAT5 (minimum) wire for each computer, printer, and VoIP phone. Yes VoIP phones do have a pass-thru so that you can share a single network cable for one phone and one PC, and if that is all that your location is wired for you should normally be ok, but for optimal results and future-proofing you should have separate network wiring done for voice and data.
If you have separate wiring you do not need to have them connected to different internet connections, however it would be recommended that your phones and computers use different internet connections.
If you only have one wire connected to both your phone and your PC you can still use different internet connections for each device, You would connect the second router to your network, turning off DHCP on one of the routers, and changing the subnet that the router is on. Then you would set either all of the phones, or all of the computers to the router that you set DHCP off.
Another internet option would be to connect your network to a multi-WAN router. This provides multiple internet connections to a single network, this provides redundancy in the event of a failure of one of the internet connections. You can also set up a multi-WAN router to send all of your VoIP traffic on one internet connection while sending your data traffic over the other internet connection.
IP phones require power. This is a fact that many people overlook. Legacy PBX phones got their power from the phone system in the closet. IP phones can get their power from a PoE switch installed in the network closet, but this will increase the initial costs of the installation and is not a requirement.
My recommendations would be:
- A local VoIP hosted PBX provider with field techs
- Separate network wiring for voice and data networks
- A PoE switch for IP phones
- A UPS back up power supply connecting all equiptment in your network closet
- A dedicated Multi-WAN router for your VoIP service for fail-over protection
Understand that most VoIP issues are not the result of the speed of your network, and increasing your internet speed rarely improves call quality. Local network configuration or congestion, as well as latency or quality issues with your ISP cause a majority of the quality issues experienced with VoIP calls. We have had customers with a specific ISP in a very localized area (within a 2 block radius) that have experienced issues even when all tests show that the connection is solid, when moving these customers over to a different ISP the issues resolved. A provider that does not have a local field tech presence would not be able to troubleshoot or resolve obscure issues such as these.
Don't forget to inquire about:
- Any issues provider has noticed with other customers on specific ISPs in your area
- Recommended speeds needed for your specific needs (how many phones, PCs, CCTV?)
- Support for auxiliary systems (door phones, intercoms, paging systems)
A final note - It is NOT recommended to have your VoIP lines behind a hardware firewall device like a sonicwall. You can maintain a firewall device for your data network but you should have a seperate router set up for your IP phones.