Small Call Center

I’m looking to setup a small call center that will need up to 85 phone extensions. I have experience with Gentoo Linux and I am very interested in Asterisk. Basicly I need to be pointed in the right direction as far as what kind of hardware I will need.

I would like to implement Voip with this call center so any providers anybody has any good experience with would be much appreciated.

I am a newbie when it comes to asterisk and voip so please bare with me :smile:

If you are planning on doing outbound dialing, there are two GPL asterisk-based dialers:
Gnidialer -

If you are planning on using VOIP trunks, how many concurrent calls do you plan on having as a peak and what kind of internet connection do you have?

You will probably be best off getting two P4 servers if you will have 85 extensions on all the time.

Initially I will start out with about 15 extensions and will have a max of 30 concurrent calls. I plan on having a T1 connection if not two. As things expand I should not have more than 170 concurrent calls.

Also, what other hardware would be needed other than the P4 servers?

Thank you for the reply

You don’t really need any other hardware other than your P4 servers if you are using VOIP trunks. You can use softphones on computers for phones or any number of the dozens of hardphones out there:

For VOIP service I would recommend IAX trunks(native Asterisk VOIP) from BinFone- They are not the cheapest provider(they do special quotes for call centers) but they have consistently great quality and wonderful customer service.

If you are using VOIP you will need to pick a codec, I recommend GSM, it’s not the highest compression, but it is good quality and takes less CPU to use meaning more seats per server for your call center.

What kind of Digital Interface Card would you recommend?

Will you be using Voice T1s or E1s instead of VOIP for your carrier?

I recommend Digium and Sangoma cards for T1/E1 connectivity. They each have their strengths and we have both in production at our company.

I think I’m a little confused. If I use voip all I would need is a 10/100 nic?

Yes and no, If you only want VOIP and don’t need very reliable music on hold or conferencing then you only need an ethernet card(10/100). but if you do want very solid music on hold or conferencing(which you will probably want for a call center) then you need at least a $15 X100P analog card to provide reliable system timing. You can get these off of ebay quite cheap and you don’t need to hook them us to anything other than having them in the PCI slot on your server with the zaptel module for it loaded.

So aside from the music on hold card. I would need two 10/100 nics, one that is connected to my voip provider and one that is connected to my switch right?

That should work. But if you have it behind a firewall you would only need one NIC card.

Yea, you only need 1 nic card. The same nic card can handle all your SIP traffic. Are you going to connect to your ‘call center’ via VoIP or via regular PSTN connection? Just curious by what you mean by T1. Data T1 or voice t1

I will be using a data T1 using voip. Also, does anybody do QoS over there switch and router or just the router?

Lets say that i use a IAX/SIP TRUNK with the provider.
Then i don;t need any kind of T1/E1 interface right?
How many concurrnt calls do you think i will be able to handle with a broadband connection of 5MB(download) and 768K(upload).


correct, you don’t need any T1/E1 interface boards for VOIP trunks(IAX or SIP)

As for how many concurrent channels you will be able to get running over that, in theory you could easily run 24 channels across 768k, but you may find that the fluctuations of latency and speed on your connection will give you bad audio if you try to run that many channels at once.