Hardware Setup for Small Office – Very Confused

After delving into various forums and doing a lot of searching on Google, I’ve managed to confuse myself as to how to deploy Asterisk in a small office setting.

Here’s the situation:

Three (3) incoming plain old regular analog phone lines coming into the office from the telco;

Ten (10) phones within the office itself (to dialout/utilize 3 analog lines).

Although I assume I need an FXO card that can handle the three incoming analog lines, I’m confused about the office side of the equation.

Can I use something like the Wildcard TDM400P – with three (3) FXO modules (for the 3 analog lines coming in) and one (1) FXS module to handle the 10 office-side phones (the 10 SIP phones would be connected to a switch or router which in turn would connect to the TDM400P)?

It’s the office-side of the equation that has me confused.

What’s the best way to connect 10 phones to the Asterisk server? Although I haven’t made up my mind, I’m thinking of deploying the Grandstream GXP-2000 phones (10 of them).

I have a similar setup, this is basically what you need:

  1. Computer with linux and * installed. Make sure the PCI slots are proper for the TDM400p (PCI 2.2 I believe).

  2. A TDM400p with 3 FXO cards. I believe it would be called a TDM403p but check me on that.

  3. A switch (i.e. Linksys, Netgear) with at least 12 ports (1 for computer, 10 for phones, 1 extra minimum).

Plug phone lines into TDM400p
Plug computer and SIP phones into switch
Configure *

My basic set up is:
POTS -> Computer with TDM400p with 4 FXO modules -> Netgear FS726TP Switch (has 24 ports, 12 have PoE) -> SIP phones

I also have a h/w VPN router plugged into the switch to allow users to VPN into the * server for remote access. They typically run soft phones on their laptops so they can get messages, call out from the office, etc.