Am I coming at this from the wrong angle

I run a small Windows network support company, just three of us, a fax, a dial-in modem and 4 incoming PSTN lines.

Currently, I just connect straight into the phone lines, so have no capability to transfer, put calls on hold or any of these that sort of shennanigans.

When the phone rings at one of my employee’s desks, I have to get my lazy arse out of the chair and go over and pick it up.

Because of the nature of our business, incoming mobile calls are the majority of our voice traffic, so I haven’t considered it a worthwhile investment to drop a few thousand dollars on a basic PBX to give us the capabilities above.

One of my new clients is looking at Asterix and discussed it with me, having never heard of it I am very interested.

Somewhere along the line, I read someone saying “this is the future of telephony, if you just want a replacement for a PBX you are in the wrong place” - but I don’t know if I fit this.

In reality, I do just want to hook my phones/modems/faxes/PSTN lines into a central system and leverage them better, but I don’t want to spend a fortune.

I am not particulary barred up for VOIP, but it is probably something I would move towards going forward, especially as my clients are starting to want to know how they can integrate VOIP into their businesses.

I have a decent internet connection (symetric 1Mb/s) so VOIP would probably be a good fit for me, but that is all in the future.

At the moment, my main interest is taking my exisiting equipment and combining it.

What I want to know is if I am adding things up right. If I want to plug my 4 pstn lines into the asterix box, and then plug 4 analog phones into it as well, do I need at least 2 x TDM400p cards with the FXO and FXS modules?

If this is the case, it is really pushing up the expense of doing the solution.

I assume people avoid this requirement by using IP phones instead of analog phones, but on that front I am probably look at a similar price to replace my analog phones with IP phones as putting in the TDM400p.

I am sure that once I put the system in with the basic features I would start to tinker with more intelligent ways to recieve support requests, route calls etc etc.

Does anyone have any input on this - I know it is a bit rambly without a point, but there you go.


i’ve seen small PABX/PBX systems for 3-figure sums that claim to provide most features people want. but then someone asks for something different, like CTI, or phones-at-home, or a network based speeddialling system, or IVR and the little system goes out of the window.

the money involved in purchasing 2 TDM400 cards isn’t huge, but if you’re thinking about expanding at any time, go for the TDM2400 card instead.

as you probably have a PC in front of you for every call, you could also consider softphones to keep the cost down. chances are, they’ll keep the call quality down too, but they are OK to start.

other options would be to buy 4 X100P clones on eBay and install those for your lines, then buy a couple of Linksys PAP2s to connect your 4 devices. all in all, that would bring your expenditure down to a few hundred bucks, and you can always add in additional hardware later.

I’d get 1 TDM400P and 4 SIP phones if it was me, i think. As you say, it’s going to cost you roughly the same, but you’re actually moving forward, rather than dragging your feet with backwards compatibility.

I’d say that an operation the size of yours is a good size to start out with Asterisk. However, you will need to develop a reasonable level of expertise with it in order to be able to run it in a production environment.

Of course, sticking with POTS lines at first, rather than switching straight over to internet telephony is good, because it means you can unplug the lines from Asterisk and plug the old phones back in if anything goes wrong. That gives you the breathing space to learn Asterisk in a more or less non-critical environment.

If you haven’t already done so, read this book: … +Telephony

I would suggest buy one all FXS tdm400 for your lines (leave fax and modem alone) and buy IP phones for your workers. Softphones suck most of the time, it’s alot nicer to have a real handset. You can get good sip phones pretty cheap, $85 for a sipura 841 or $100 for a grandstream gxp2000, both are quite capable.

The fact is, phone systems (especially ones with feature sets comparable to Asterisk) are very expensive. To get an Asterisk-equivalent PBX out of a major vendor would cost several thousand dollars, $10k-$20k when you scale it up.

If you aren’t prepared to spend at least a few hundred bucks then you could try softphones and x100 clone cards but you aren’t going to be nearly as happy with the result.

I would have to agree with Ironhelix. Softphones suck. Who wants to boot up a PC just to make a phone call? And definately leave the fax and modem off the Asterisk system. Unless your planning on needing faxes delivered remotely through fax to email, there’s no benefit to putting them through there at all. You can always route the fax into the Asterisk for fax to email delivery some day in the future, but your first step should minimally disruptive.

Go with Willkemp’s suggestion for the parts. A TDM400P and 4 sip phones would be just what you want. The only other things you’d need would be a decent server and a good ethernet switch (which, being an IT company you probably have lying around).

Put it all together with a nice front end IVR menu for callers (“To reach so-and-so, press 1”…) and all the basic features like voicemail, music on hold, conference, and transfer.

Bung all of your analog lines into it, and you’re all set. When you get feeling frisky, you can add things like fax to email delivery, or find me services. ("To ring so-and-so, press 1 " will ring his desk and mobile phone.) The new features will cost nothing more than the time you take to implement them, and new phone stations cost no more than the individual phone and 1 ethernet port.

The per station cost (for SIP phones) is considerably less than traditional PBX costs. Ports on a PBX or key system are generally very pricy, as are the phones they support.

The whole thing can be had for less than $1000US. (Assuming you have a decent server and ethernet switch already.)

Opinion follows: Stop reading now if you’re not interested.

When everyone talks about Asterisk as “the future of telephony”, it’s both correct and misleading. Asterisk is really more like the “next step of telephony” than the future. In the future, we’ll all just plug our VOIP phones into the network, register them with our “messaging server” (probably modified email servers) and just dial everyone by network/email/phone addresses. (Dialing: The PSTN companies will have been reduced to being gigantic network providers, and the VOIP companies (Vonage, et al) won’t be around because their only reason to exist is to connect your internet based call back to the PSTN. With no PSTN left, they’ll be through.

Right now the best thing for VOIP to do to gain acceptance, is to emulate the services we know and love. So, that’s what it’s doing. However, we’ve all plugged 2 VOIP phones into switches and, simply by dialing an IP address, made one phone ring the other phone. No Asterisk or VOIP company necessary.

It won’t be long before we’re doing that on a larger scale with a different address scheme. We just have to learn to let go of the idea of phone numbers being the address of a phone call. Once we do that, the future will be here.

Will someone PLEASE kick the soapbox out from under me?

actually no, i agree almost 100%. I think there will be an additional abstraction layer, or at least a way to keep an address when you switch providers or ISPs. I look forward to the day when a cell phone is little more than a wireless network interface with a voip client loaded on it, and they’ll probably all be PDAs then. I think that Jabber/XMPP will be a big part of that future, and it will find some way of happily interoperating with SIMPLE. With an email-like address, or perhaps some sort of abstracted address, you will be able to reach a person’s voice, email, and IM functions. That will be fun, and Asterisk will help get us there.

Ok, here’s my 2 cents worth. Buy 1 tdm card. Dump three of the 4 pstn lines (think of the rental savings here) Have your remaining line on a divert to your IP dialing phone number. Populate the tdm card with one FXO module as a failover incase broadband dies. You then have the option of 3 fxs modules to plug analogue phones into, and with the money you saved, have a sip phone for yourself. Pay back in about 9 months :smiley:

The only problem with this is my ISP bundles 4 analog lines along with the 1mbps SHDSL service at a very low price, they don’t give it to you any cheaper if you don’t want the analogs, so I may as well use them.

They are actually using some type of different technology to bring those lines in - whether it is VOIP or something else I don’t know, but they deliver a single copper pair, plug their router in, and the router presents up to 8 analalog phone ports and an ethernet port for the data.

One of my questions relates to my headsets. I have purchased 3 Plantronics headsets for us, as talking and typing can be quite essential. The analog phones I have ( have a builtin headset port, so I don’t need to use an amplifier from Plantronics (costs more than the headset from memory) - am I going to find an IP phone with the same type of port in the low end of the market?


ahhh… their ‘router’ is really a DSL modem, a router, and a 4 port ATA all in one device! You should call them and see if they’ll let you get the SIP cridentials, that way you could link your * server straight into their system without the POTS ports.

As for headsets, your link is light on specs. Most headsets these days use a 2.5mm 3-conductor headset port (looks like a normal discman stereo headphone jack but is thinner and less deep). This is a standard port and many phones feature this type of port, or can provide one with an inexpensive adapter. If it’s something else, i’d need a picture of it and the headset plug. here is what a 2.5mm headset plug looks like (link blatantly stolen from google imagesearch) I believe the new Grandstream 101 has such a port. The grandstream gxp-2000 has a 3.5mm port but it can be converted with a $3 adapter from radio shack. Many other phones have a 2.5mm port.

The headset that I have is: … prod440052

It has a little RJ11 style jack to plug into the side of the phone, I don’t have my digital camera with me though.

Found it on the net:

[quote=“IronHelix”]ahhh… their ‘router’ is really a DSL modem, a router, and a 4 port ATA all in one device! You should call them and see if they’ll let you get the SIP cridentials, that way you could link your * server straight into their system without the POTS ports.


I doubt they are going to be keen to play ball on that, but it would be interesting to try.

I am actually interested to know exactly how they do deliver the service. They have been having some problems over the last few months with the lines just failing, every time I call to yell at them they tell me it is a problem with the PSAX (sp?)

The equipment they put onsite for me is a Verilink 8508S IAD, as I mentioned before it has 8 analog ports and an ethernet port.

Is this enough info for anyone to know what they use, and whether theoretically I could use an Asterisk box instead of having the router present the analog lines for me?

Actually, I’ve tested and used headsets with VOIP phones.

I’ve tested Plantronics Supra and Encore headsets on several VOIP phones.

Specifically, the Sipura 841, the Cisco/Sipura/Linksys-941, the Grandstream-2000, and the Polycom IP500.

With the exception of the Polycom IP500, they all use a 3.5mm plug. (Which is nicely the same as, and compatible with, your mobile phone headset.) The Polycom uses an RJ-14 and needs an amplifier.

To adapt the Plantronics headset, you need to buy one of these:

The only downside I’ve found is that the cord length can be a bit short. The cable that Safetyboy found is intended to give headset cords their length. However, Plantronics makes extensions, (with a quick disconnect on each end) or you can just buy a 3.5mm extension.

All of the phones answer by simply pressing the “headset” button. None of the annoying adapting in the middle of a handset cord.

They all work quite well. I had to raise the headset gain in the 841 and the 941, but after I did that, it was just the same as my non-VOIP phone on my desk.

Here’s the datasheet link about the product:

Interesting story to share since we’re talking about what the future is:

I was talking to a recruiter I’ve used in the past (both hiring and being hired) at Robert Half International (for those who don’t know them they are a very large source of contract and permanent technology skills in the US.)

He mentioned they had just purchase a new phone system and had passed on the Cisco solution and decided on ShoreTel. He thought they were the largest ShoreTel site to date – 120 sites! Pretty impressive given the momentum and heft Cisco brings to the table.