Here is my current situation: I have a pretty good grasp on networking but I'm a complete newbie when it comes to phone systems other than the many hours of YouTube/PSP websites I've been scouring.
I've got a customer with around 40-50 employees between the two departments. The two departments are in the same building. We are going to be putting in new, separate LANs (new cabling, patch panels, racks, switches, firewalls, the works) in each department. Why not VLANs you ask?
They don't want to split their bandwidth between the two departments (they each currently have their own LAN/gateway/servers.) I know this could be probably be accomplished by correct configuration in the SonicWall, however, read below.
Both bosses have agreed that they don't want the networks physically connected.
At this same time the customer has expressed they would like to upgrade their old outdated phone systems. These phone systems are what looks to me to be an older analog system with possibly either a T1 (or multiple) feeding into it or some other type of technology I'm ignorant about. I'm going to be getting a copy of the customer's bill soon to better determine exactly what they were paying for and what they require.
The problem at this site is that the only high speed internet currently offered in the area is 15/2 DSL and a 15/2 cable. We've already figured that we're going to, in all probability, keep the LAN separate from the phone system as 15/2 definitely wouldn't be enough bandwidth to distribute between all of the phones and the LAN. We will probably be brinigng in two different patch panels, one for LAN and one for phones. Each patch panel will get it's own gateway and switch. The questions I currently have are these:
Is 15/2 enough to support SIP trunking with approximately 25-30 concurrent users?
If we DID have the bandwidth to keep the phone system and the LAN together, what would be the advantage of having everything under a single gateway as opposed to multiple (other than eliminating the cost of another uplink)One answer to this question could be that without having the IP PBX (if we choose to go on-site PBX as opposed to cloud) integrated into the LAN then you wouldn't be able to use softphones on the LAN to communicate with the PBX. Someone may need to verify or debunk that statement.
Considering 15/2 as an up/down and the amount of users, would you be looking towards an on-site PBX or cloud-hosted PBX?
Having little experience with IP phone systems but having proficient technical knowledge of networking, would you suggest an outsourced platform such as RingCentral/8x8/ShoreTel or do you think 3CX or any other equivalent would be manageable?
Would I be doing myself a favor to get proprietary gateways/hardware from someone like 3CX/ShoreTel that already comes configured for their phone systems? My concern is that I'm not really sure how the technology works. Do you just need something like a ShoreTel voice switch combined with an uplink and then a PoE switch for the phones?
Should we also be considering keeping the phone systems separate as well due to bandwidth? This would create an environment where you would have around 25 in one department and around 15 in the other, with around 10 concurrent calls on one side and possibly 8-10 on the other.
Sorry for the extensive read, but I would super appreciate any kind of feedback (however much.)