One phone number but multiple simultaneous phone calls? (Using sip trunk)

I’ve just setup freepbx with a sip trunk through sipstation. Works great!

I think I would be able to setup multiple incoming DID’s each having a different phone number (just have a different inbound route setup for each DID) but I haven’t been able to learn how to setup a situation where you have one number with many lines to allow for multiple incoming phone calls.

Do I have to set that up with the phone company or can I get this worked out by just increasing the number of channels on my sip trunk? If I just increase the channel count, do incoming calls still go through the same path (IVR) as the first call?

Anyone aware of any guides or tutorials on this subject?

Conveniently, to your right of your screen, under “Quick Nav” is a link named “Documentation” it is also under “Resources” at the bottom of your screen.

Start there maybe? all will be revealed.

I love these posts where people think you haven’t read the documentation. None of the topics regarding SIP trunks seem to address this issue in the Howto section. The FAQ doesn’t have any topics that appear to address it either. Even the main thread that discusses how to setup FreePBX trunks provided by doesn’t explain anything other than to say: “You do not need to set the Maximum Channels field in your trunks with FreePBX SIP Trunks. If you use more channels than you have purchased, the network will signal congestion properly allowing other fail over trunks to be engaged if you have configured them in your route.”

Anyone care to provide assistance? Dicko, please feel free to ignore this thread and continue to post similar helpful comments to others.

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Then perhaps more particularly from those links:-

Would seem ;particular to your needs. In your case refer to:-

Inbound Routes- The Inbound Routes module is where you tell the PBX how to handle incoming calls. Typically, you tell the PBX the phone number that outside callers have called (“DID Number” or “Direct Inward Dial Number”) and then indicate which extension, Ring Group, Voicemail, or other destination the call will go to.

. . . extension, Ring Group, Voicemail, or other destination . .

are also covered in thst document.

Thank you Dicko. I read that as well. Please notice that this documentation also doesn’t explain one phone number with multiple channels attached. In fact, the word “channel” doesn’t even appear in it. It does explain what an inbound route does which I have already setup successfully with one channel so I think I’m past this.

I’m just trying to find someone that has done multiple sip channels in one trunk with one phone number. I’d like to know how that works.

If I was using regular copper incoming lines from the phone company, I believe I’d have them setup a “hunter” group or something. Since I’m not doing that but, rather, using a sip trunk, I’d like to learn more about multiple channels and how they route when in use simultaneously.

I’ve not only searched freepbx’s forums exhaustively but google overall. Either it’s so simple that nobody talks about or so hard, nobody does it. I’m guessing it’s the former but I’d like to learn that for sure before ordering more channels and experimenting.

A trunk is generally considered to be a collection of “lines” or circuit or channel you get one “line” per copper pair, in NANP land 23 or twenty four channels on two pairs (a T1). A “hunt group” is a bunch of lines that ring in a predefined sequence, they will normally have individual numbers also on each line,SIP trunking does not have that one “line” per pair limitation. in FreePBX a hunt group is called a ring group, you can extend the concept of inbound multiplicity to IVR’s, Queues, Time conditions, Parking Lots, DISA and a whole bunch more. You will have to learn how they differ from each other though. DID’s (Direct Inward Dial i.e. a phone number) are just individul numbers that can be separated at source on the sip trunk and sent wherever you want.

Seriously this is all well documented here and on google and elesewher, maybe is a good start for a newbie, it covers VOIP in general and Asterisk more specifically, some consider it required reading.

Ok. I’ll go ask there.

They won’t answer, It’s more a wiki, but there is plenty of “core” stuff that you can read and get all your questions answered.

If you need more hands on help, then the “Support” link under “Resources”. at the bottom of the this screen, will happily take your money to re-read you all of the basic manuals whose content seems to have so far eluded you:-)

I always find it helpful in trying to resolve a problem to find out exactly what you are trying to do. Not the technical stuff, simply what you are trying to accomplish.

A single phone number can ring multiple phones through the use of a Queue, Ring Groups, or an IVR, if you want the user to have to punch buttons.

The main question…how many channels do you have available? That is the max number of simultanious calls (inbound/outbound) you can have.

Yup. That’s what I’m trying to do: Send all simultaneous calls from the same phone number (which I believe means same SIP trunk) to the same IVR where the user will select their respective options.

So it’s just that simple and there’s no extra configuration - if a caller calling your number is already sent to your IVR, increasing the number of channels will allow multiple inbound callers to use the same IVR at the same time? That’s pretty simple!

No, although as you state it is pretty simple, you still have it confused, the trunk is a “stream” through which one or many “DID’s” can travel to you, each one one or many times. when you get a call from that DID, you arrange with your “inbound routes” where you want that partiular DID to go to. the number of individual calls that can reach you is limited by the number of concurrent channels that you have bought from your vendor, and effectively what bandwidth you have and what codec you care to use.

Please understand the difference, DID’s and Trunks are not the same thing. Many DID’s can ride on the same trunk, trunks limitations depend on the contract you have with your vendor

I think I’ve got a handle on the difference between a DID and a trunk. I already have one DID riding inside a SIP trunk with one channel. Since I only want one phone number but would like to be able to handle more than one call coming into my IVR at the same time (through the same number/DID), I would simply increase the channels of that trunk wouldn’t I?

It’s different with how each carrier bundles. SIP Stations sells unlimited channels. 1 channel = 1 talk path. Trunks can have as many virtual channels as the carrier assigns.

Some carriers charge per minute so they don’t care how many calls you have up on a trunk.

DID’s are phone numbers and they are routed to trunks.

As far as forums are concerned, you should try and ask specific questions. Forums are not intended as tutors in the subject matter. If you are installing an IP phone system we assume you have a basic knowledge of telephony, networking, Linux and IP telephony.

If you come in without these skills (and this is true of any technical forum) you are going to get ignored or flamed.

I personally would, but I read the manual, several times.

Basically increasing the channels is it. Remember, that outgoing calls need a channel too. And…might you also want to get a few extra DID’s so that supervisors, administrators, etc. could have a private direct number?


Basically increasing the channels is it. Remember, that outgoing calls need a channel too. And…might you also want to get a few extra DID’s so that supervisors, administrators, etc. could have a private direct number?

Well … to go further into this question, let’s say I have 10 input channels provided in a trunk, an inbound route directing to a queue where agents are 10 internal SIP extensions, can I answer 10 calls simultaneously ?

Perhaps if you are an male octopus and have a prehensile penis. Otherwise you might need some more people to answer those 10 calls you will be getting on your 10 channels.

But the octopus would have pointed the inbound route to a ring group or a queue.


but which of it’s “fingers” would be pointing in the right direction?

I just have one question…have we been in this business too long?