New to VoIP

Hi, I’m new to VoIP and I was adviced to use Asterisk for my PBX server.

Nowadays, I have an analog PBX with 5 PSTN lines (FXO?) and 25 internal phones (FXS?)
The plan is to implement VoIP keeping the 5 PSTN lines and using the same internal phones. In this way, I would call through VoIP to call other PSTN in other cities or countries and continue to use my local PSTN lines to make local calls.
Is it possible to integrate this with Asterisk? If possible, what would be my hardware needs? how should I connect everything?

Many Thanks

Sounds fine, Asterisk can do all of that.
Hardware: for the FXO, get a Digium TDM400P (or the equivalent from Sangoma, they very good). You would need 2 of those, and 5 FXO chips. For the internal phones, get a channel bank for this.

First, if the phones you are talking about are PBX system phones that came with your old analog PBX, they won’t work with Asterisk. You might be able to get some kind of link going between * and your old PBX, so the old pbx becomes an adapter basically, but this probably isn’t worth your time. If you really want to use the old phones, Citel may make an adapter that will let you use them

for the internal phones I’d go with good IP phones- SNOM or AAstra.

However if your existing PBX works and you only want to add VoIP to the mix (IE no advanced features, just a different call route), you may not even need *. Just get some ATAs registered to your ITSP of choice and plug them into spare line ports on the PBX. Then it can choose which line to dial based on what you call (if it has this ability)…

Why not? yusuf has already mentioned channel bank for internal phones. Unless you really need those “stuff” on IP phones you can’t get from old phones, there’s no need to replace them. (One good reason to replace is to simplify wiring.)

many thanks for all your replies.

in fact, that’s what i’m trying to do… simplify wiring and reducing costs. i do not need the special functions available with IP phones, i just need them to be able to make and recieve calls (after i set up all this, i’ll be thinking of adding functionality).

so, all i should do is connect the internal phones to the channel bank and the FXO to the card? which would be the hardware requirements for the server (processor, memory, etc)?

One of FAQ’s in is Asterisk hardware. It contains links to some testimonies.

link should be

OK for many of the four line and above PBXs the phone will not work with the FXS port.

Easy way to test is take and plug the phone into a STANDARD TWO wire jack (like a fax machine or home phone)

those 4 / 6 / 8 line phones will not work without an adapter which is VERY costly (24 ports over 3000.00)…and in many case you end up with a phone which sounds like a 40.00 BT phone anyhow…

So at 125.00 plus a port to convert it may be wise to look at IP Phones

for the nortel / panasonic KX folks who wish to CHEAPLY add VoIP lines to the system, we just hang a ATA off it and have the users use the VOIP line to call out when needed…

Add a few paths (pipes) to the main Analog lines and add CWoNA / CWoB to a VoIP DID setup on the ASTERISK and all is good…

In my office witha Nortel KSU

If I hit line 1 or 2 I go out over the PSTN via the Nortel KSU

If I hit line 3 or 4 I go out over a VoicePulse line (ATA’s hanging off the KSU Co ports) setup as exten on remote box passing the CID of the PSTN lines)

If I hit line 5 or 6 which are ATA’s setup on two remoted hosted PBX’s
I am hitting other PBX’s as an exten and can call internal as well as outbound from the remote boxes as exten on the remote systems and I Pass the remote boxes CID’s.

We all use the Nortel Phones and softphones w/ USB headsets on the PC / Laptops

The way it is setup we all can look at the phones and see which line is ringing and know how to answer the phones.

The three groups are answer different
1-2 company one (pots with CwoB / CWoNA to VoIP 4 VM / follow me)
3-4 company two (CVP Voip lines)
5 company three office A (Exten on remote box a)
6 company three office B (Exten on remote box b)

No local asterisk box all boxes are remote, which is why no FXO card in a Asterisk server.

sorry was afk for a while

When I say PBX system phones, I do not mean normal analog phones like you get at Radio Shack. I mean PBX phones, ie the Avaya phones that come with an Avaya PBX. They MAY work a little bit with a standard FXS port from a channel bank but the feature keys (LED buttons, transfer, conf, etc) will almost certainly NOT work. THis is because the phones all use a proprietary signalling to communicate with their host PBX, which a channel bank won’t be supplying. There is one company that makes a handset gateway product which will provide this signalling so you can reuse your existing phones and keep the wiring. However the Citel product isn’t cheap…

As Bubba says you can test by plugging a phone set into a jack and see what you get. It probably won’t be much.