Hi, I'm a computer engineer with basic knowledge of telecom. Actually, less then basic to be honest. I've been playing around with Asterisks for a few weeks with 2 FXS and 2 FXO cards, and having a bit of fun making a home PBX. I'd like to know how I could apply this new knowledge to, for example, developping a PBX solution for this following hypothetical company: - Exactly 72 employees each with a direct telephone number that goes directly to their phone. Ex: Bob is 444-555-6666 and Lisa is 444-555-6667. Let's say they don't have a PBX yet. - Statistically, the max number of outside lines ever busy at the same time was 24 (how conveniently T1-like). They don't want to change their business cards, so 444-555-6666 should still reach Bob, but now by going to the PBX first. The PBX should recognize that the call was made to 444-555-6666 and switch it to Bob automatically. Bob should see the Caller ID of the caller on his phone. This is it. Conceptually, not very complicated. My guess is I would need (and this is where I need confirmation from somebody in the know): - Asterisk PBX - A Digium T1 line for a connection to the phone service provider (I'm in Canada, so let's say Bell Canada for argument's sake) - A T1 line from Bell Canada (or other) - Something (not sure what) on the outside to connect to those 72 phones (3 T1 cards internally connecting to a wire panel, in turn connected to 60 phones? Is this it? Do I need anything else? Follow-up questions: a) Is is possible to have 72 numbers associated to a single T1 (more numbers than lines)? b) Will Asterisk be able to recognize (and how?) which number the call came on, so it can run the right dial plan? c) This migth be a Canada-specific answer, but I'll try: When leasing a T1 line, does the regional code have to be based on geohraphy? Could I have a T1 with 416 (Toronto) numbers located in Montreal (514)? I sure hope my questions weren't too "newbie-like". I fear they are, but I've really tried finding the info on the web. I certainly wouldn't be insulted if the only reply I got was a link to a decent Web site explaining all this. Mike
Hi, I'm a computer engineer with basic knowledge of telecom. Actually, less then basic to be honest. I've been playing around with Asterisks for a few weeks with 2 FXS and 2 FXO cards, and having a bit of fun making a home PBX. I'd like to know how I could apply this new knowledge to, for example, developping a PBX solution for this following hypothetical company: - Exactly 72 employees each with a direct telephone number that goes directly to their phone. Ex: Bob is 444-555-6666 and Lisa is 444-555-6667. Let's say they don't have a PBX yet. - Statistically, the max number of outside lines ever busy at the same time was 24 (how conveniently T1-like). They don't want to change their business cards, so 444-555-6666 should still reach Bob, but now by going to the PBX first. The PBX should recognize that the call was made to 444-555-6666 and switch it to Bob automatically. Bob should see the Caller ID of the caller on his phone. This is it. Conceptually, not very complicated. My guess is I would need (and this is where I need confirmation from somebody in the know): - Asterisk PBX - A Digium T1 line for a connection to the phone service provider (I'm in Canada, so let's say Bell Canada for argument's sake) - A T1 line from Bell Canada (or other) - Something (not sure what) on the outside to connect to those 72 phones (3 T1 cards internally connecting to a wire panel, in turn connected to 60 phones? Is this it? Do I need anything else? Follow-up questions: a) Is is possible to have 72 numbers associated to a single T1 (more numbers than lines)? b) Will Asterisk be able to recognize (and how?) which number the call came on, so it can run the right dial plan? c) This migth be a Canada-specific answer, but I'll try: When leasing a T1 line, does the regional code have to be based on geohraphy? Could I have a T1 with 416 (Toronto) numbers located in Montreal (514)? I sure hope my questions weren't too "newbie-like". I fear they are, but I've really tried finding the info on the web. I certainly wouldn't be insulted if the only reply I got was a link to a decent Web site explaining all this. Mike
On Oct 20, 2005, at 1:15 PM, Micha?l Gaudette wrote:> I'm a computer engineer with basic knowledge of telecom. Actually, > less then basic to be honest. I've been playing around with > Asterisks for a few weeks with 2 FXS and 2 FXO cards, and having a > bit of fun making a home PBX. I'd like to know how I could apply > this new knowledge to, for example, developping a PBX solution for > this following hypothetical company:Welcome! Asterisk can definitely do what you are looking for, and save this hypothetical company money in the process, I bet. (The T1 should be cheaper than 72 analog phone lines, if that's how they are doing it...).> - Exactly 72 employees each with a direct telephone number that > goes directly to their phone. Ex: Bob is 444-555-6666 and Lisa is > 444-555-6667. Let's say they don't have a PBX yet. > - Statistically, the max number of outside lines ever busy at the > same time was 24 (how conveniently T1-like)Well, this is a hypo, but 24 simultaneous calls is a bit close to the maximum for comfort. I would want a few extra lines available for growth, unexpected peak calling usage, etc. (What happens in an emergency/serious problem at multiple customers, or anything else unexpected where call volume spikes?)> . They don't want to change their business cards, so 444-555-6666 > should still reach Bob, but now by going to the PBX first. The PBX > should recognize that the call was made to 444-555-6666 and switch > it to Bob automatically. Bob should see the Caller ID of the > caller on his phone.Yes, this will easily work via the T1. Your Provider will send the DNIS information when the call comes in. Normally they provide the last 4 or last 7 digits of the dialed number (Choose seven. We used to have 4, but we ended up with two numbers that had the same last 4 digits.) Asterisk uses this info to route the call to the correct phone. CallerID will come in, too, but a T1 can only provide CallerID Number, not name. A PRI is necessary for CallerID Name.> This is it. Conceptually, not very complicated. My guess is I > would need (and this is where I need confirmation from somebody in > the know): > - Asterisk PBX > - A Digium T1 line for a connection to the phone service provider > (I'm in Canada, so let's say Bell Canada for argument's sake)Yes, but you could use a Sangoma card, too.> - A T1 line from Bell Canada (or other) > - Something (not sure what) on the outside to connect to those 72 > phones (3 T1 cards internally connecting to a wire panel, in turn > connected to 60 phones?You could use: 1.) IAX or SIP softphones 2.) SIP Hardphones (Cisco, Polycom, etc.) 3.) Analog phones connected to a Channel bank, connected to a T1 card. If you choose option 3, you could buy a quad-span T1 card from Sangoma or Digium and use one port for the incoming T1 or PRI and the other three for extensions. Then if you need to add another incoming T1 for incoming/outgoing calls or extensions, you could add another T1 card. you could also use ADSI screenphones if you choose, though many would prefer SIP hardphones at that point.> Is this it? Do I need anything else?Well, experience, patience, and a working dialplan will all be important! I would personally recommend a GUI configuration tool, such as AMP, IPManager, or something of the like. This, of course, depends on your preferences, though, so feel free to hand-code if you so desire. For something like this as your first serious production install, you might want to consider hiring a consultant.> Follow-up questions: > a) Is is possible to have 72 numbers associated to a single T1 > (more numbers than lines)?Yes. You will have to port the existing analog numbers to the T1, which will disconnect the existing analog line. What you might want to do is start with one phone number and port it to the T1. plug the user's phone into the asterisk server, and make sure it works as expected. Then port another ten numbers and make sure that they all work. Keep porting numbers in groups of ten, twenty, or whatever you feel comfortable. That way if something doesn't work, you will only have 1, 10, or however many people whose phones are not functional, not all 72.> b) Will Asterisk be able to recognize (and how?) which number the > call came on, so it can run the right dial plan?Yes, see comment about DNIS above.> c) This migth be a Canada-specific answer, but I'll try: When > leasing a T1 line, does the regional code have to be based on > geohraphy? Could I have a T1 with 416 (Toronto) numbers located in > Montreal (514)?Not certain. We have phone numbers from throughout the state (all in the same Area Code) ported to our T1, so a customer can dial a local number but the call still comes in to our central office. Whether this is possible between area codes, though, I don't know.> I sure hope my questions weren't too "newbie-like". I fear they > are, but I've really tried finding the info on the web. I > certainly wouldn't be insulted if the only reply I got was a link > to a decent Web site explaining all this.No, but again, you might want to consider hiring a consultant before you tackle something like this. At the very least, take it slowly as I suggested above. Tom ------------------------------------ Tom Rymes Cascade Link Systems www.cascadelinksystems.com (603) 375-1414 Technology solutions for small & medium sized businesses
>Exactly 72 employees each with a direct telephone number that goes >directly to their phone. Ex: Bob is 444-555-6666 and Lisa is 444-555-6667. >Let's say they don't have a PBX yet.Easy as pie with a PRI/T1. Typically the telco assigns a DID (Direct Inward Dial) number to the PRI and Asterisk parses the last 4 digits of the DID to assign it to an extension in the incoming context. So for a number that is 555-1212, Asterisk will expect a statement like this in the incoming context: Exten => 1212,1,Dial(somewhere internal) This extension number is only valid for the incoming context so of course you can have an external "extension" that corresponds with the DID and an internal extension number that the user can dial other phones with. They are mutually exclusive.> Statistically, the max number of outside lines ever busy at the same time >was 24 (how conveniently T1-like). They don't want to change theirbusiness>cards, so 444-555-6666 should still reach Bob, but now by going to the PBX >first. The PBX should recognize that the call was made to 444-555-6666 and >switch it to Bob automatically. Bob should see the Caller ID of the caller >on his phone.Yup see above. You need to assign all of the existing numbers as DID's on the PRI.>Asterisk PBX - yes>A Digium T1 line for a connection to the phone service provider - actuallya Digium or compatible PRI/T1 *card*>A T1 line from Bell Canada (or other) - yes >Something (not sure what) on the outside to connect to those 72 phones (3 >T1 cards internally connecting to a wire panel, in turn connected to 60 >phones?If you are using IP phones then you leverage your existing Ethernet infrastructure. If it is 72 regular, analog phones then you need an FXS Channel Bank. Google for it. Try to convince them to use IP phones, they rock.>Is this it? Do I need anything else?Experience and patience. And a backup to help you out if you are stuck like a consultant on -biz>Is is possible to have 72 numbers associated to a single T1 (more numbers >than lines)?Yes, up to 10K per PRI assuming 4 digits are passed by the PRI, sometimes you can get 7, ask your telco Will Asterisk be able to recognize (and how?) which number the call came on, so it can run the right dial plan? Yes, see above This migth be a Canada-specific answer, but I'll try: When leasing a T1 line, does the regional code have to be based on geohraphy? Could I have a T1 with 416 (Toronto) numbers located in Montreal (514)? Talk to your telco. They can probably do it but you will most likely have to eat the long distance. hth