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[SOLVED]multiple remote extensions, same network

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ZenMasta

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I'm testing a scenario where 3cx is in the cloud and all extensions are remote. The problem seems to be that if you have more than 1 extension at the same location, only 1 of the extensions is guaranteed to be able to receive inbound calls, and the rest will not likely ring.

I was playing around with this at home yesterday behind a linksys (ddwrt flashed) router. I had 2 spa504g phones and 1 3cx softphone using tunnel. For only a SHORT period of time, I was able to call in from my cell phone and all 3 extensions would ring. I tried several times and was able to answer the call on each extension with 2 way audio.... but eventually it came down to only one extension ringing and being able to answer the call.

In this same setup, all the extensions can make calls no problem with 2 way audio. It's just the inbound with multiple extensions on the same network that causes the problems. I've tried both at home and at the office and experience the same problem. Whichever phone registers first on port 5060 will accept the inbound calls but any other registrations might ring, but you wont actually be able to answer the call.

How can I overcome this?

[SOLUTION]
CHANGE sip port on individual phone


DISCLAIMER - do not read the rest of my posts unless you want to get extremely confused!!!!
all of the crazy problems I was having were a result of me realizing the phones could not provision remotely, and the new extensions I had attempted to reconfigured were still configured to connect on a lan, so I hadn't configured advanced nat options per this article http://www.3cx.com/blog/voip-howto/remote-extensions/
 
Re: multiple remote extensions, same network

Be sure that you have assigned a unique port number to each set...5060, 5061, 5062...etc.

This is the port of the device, NOT the port that the device contacts 3CX on.
 
Re: multiple remote extensions, same network

how does one accomplish this?
this would require a static private ip and the router would have to support it - yes?
 
Re: multiple remote extensions, same network

Thanks Leejor,

So if I can clarify. 3cx server firewall doesn't need any new allowances?

Changing on the phone only sounds simple enough, I'd just have to provision and then make edits and turn off provisioning. Where do I configure this change on my SPA504g phones?

SIP Tab:
SIP TCP Port Min: 5060
SIP TCP Port Min: 5080


EXT 1 Tab:
SIP Settings>Sip Port: 5060 <----change this??
 
Re: multiple remote extensions, same network

ZenMasta said:
EXT 1 Tab:
SIP Settings>Sip Port: 5060 <----change this??

That's the one.

Have a look at the 3CX log just after a remote device has registered, you will see that it shows the remote public IP and a port number. This is how it will send any SIP messages back to that device. So....you can't have multiple devices using the same port or they all look like the same device to 3CX. The remote router should sort out which set is using each port and forward the messages on without the need for any port forwarding being set up.

However....Depending on your router (I use DD-WRT myself), you may end up having issues if you have too many sets. Some routers can become "confused" when it comes to which set gets the voice packets, resulting in one way audio. the more sets, the more chance of this happening, that's why 3CX came up with the Proxy Manager.

http://www.3cx.com/blog/help/3cx-downloads/

If you are running the DD-WRT VoIP version, there is a Milkfish option which acts much the same way, sorting out multiple devices when you are communicating with one SIP server. You might want to investigate that. I haven't had a need to make use of it myself but did play around with it a couple of DD-WRT versions back.

http://wiki.milkfish.org.sipwerk.com/index.php?n=Milkfish-dd.RouterConfiguration
 
Re: multiple remote extensions, same network

My situation is similar.
Local 3cx phone system.
Remote Extension calls internal - all is well. Works fine.
Local Extension calls Remote Extension - rings on other end - I answer. The local end doesn't know I answered the call. I hang up remote. The Local Extension doesn't know I hung up. Then the remote rings again from the same extension.
In Wireshark, I see an Invite but no Ack sip:ext@ip:port

Local End - Watchguard Firebox
Remote End - Netgear WNR2000 with only 1 handset - Yealink T22. (although I did try changing Local SIP Port for the heck of it to 5070,
I've tried utting it on the DMZ, I've disabled SIP ALG)

What makes this easy for testing is I can do this all from my office - because I have a Static Public IP from our provider in my office, as well as another jack which is the internal network.

The problem will be is I do not know what hardware the remote side will have, as these will be home offices.

I have the settings as in the article - SIP Server, Nat Traversal to use STUN, RPort, Keep Alives...
I also can not use the Proxy Manager as these locations run on Mac Book Pro's.

Any ideas...
 
Re: multiple remote extensions, same network

craigreilly said:
Local Extension calls Remote Extension - rings on other end - I answer. The local end doesn't know I answered the call. I hang up remote. The Local Extension doesn't know I hung up. Then the remote rings again from the same extension.
In Wireshark, I see an Invite but no Ack sip:ext@ip:port

If you are just dealing with one extension , at the remote location, having problems, then it sounds like it could be a router issue, but at the local end. If the remote set shows as registering, using the public IP of the remote router and the unique port number (on that network), then 3Cx should be able to get messages through, which seems to be the case, as the set rings.

Your problem is that 3Cx is not receiving a message when the set is answered, the no Ack, or hung up, from what I gather. Be sure that all of the necessary ports are forwarded at the local end. It might be a local router/firewall option that need to be changed too.

Unless they are being misdirected then it would appear something is blocking messages sent from the far end.
 
Re: multiple remote extensions, same network

Strange I see nothing in my hostwatch for the WatchGuard coming from PBX IP 10.0.0.12 or to Public IP when I make that call.
So I try by Port - nothing on 5000,5060,9000-9049.

And any calls made on my VOIP trunk do not show in the HostWatch. Strange....
 
Re: multiple remote extensions, same network

Hey leejor,
I incremented the port on one of the extensions and I think we're in business. I'll be testing periodically throughout the day but so far so good. Thanks!


[edit 2] the 3rd extension finally registered, but it's still showing the lan ip instead of the public IP like the other extensions do. Despite this oddity, I can make and receive calls on that extension, BUT after extension 100 or 103 picks up the call, the LCD on extension 101 is stuck showing the inbound call from the ringgroup... even after the call is completed.

You can see the extension status in 3cx it will show that extension stuck Dialing OUT.
After a few minutes it will say Internal Server Error and have that busy signal.... I was typing as that happened so I didn't get a chance to take a pic, it only lasted a few seconds.

If I disconnect power to extension 100, it still shows registered on the server, it takes a while before it drops off, unlike other extensions which would usually drop off almost instantly.

[edit] I just attempted this on a 3rd extension and I'm having some issues.

1) I set port to 5062
2) phone will not auto provision so I had to change IP's manually
3) when it finally registered, instead of showing my public IP it showed the lan IP
4) after rebooting phone/restarting all services it is not registering anymore.

I'll keep fenagling :)
 

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Re: multiple remote extensions, same network

It seems now even with ext 100 disconnected, I am still having the problem with ext 101 status showing dialing instead of ringing on an inbound call
 
Re: multiple remote extensions, same network

OMG this whole situation is REALLY bizarre and it's really blowing up in my face.

I looked more closely and when I saw extension 101 was "dialing out" it was using a different trunk (i had a conflict in outbound rules) going out but since that trunk hadn't been configured yet the call wasn't successfull.

Lets say I make an inbound call from a pots/cell phone example 8311234567

Well now, the extension status, instead of saying Ringing, they say dialing, and they are attempting to call the number that was calling in!!

I thought I was golden this morning, now feeling a little hopeless.

So here's what I did
1) I deleted the obsolete outbound rules for the other gateways so I only have 2 OB rules for my 1 voip provider
2) I also went ahead and deleted those pstn devices (fxo gateways)

3)powered off all extensions
4) restarted all services in 3cx

5) powered up ext 101
6) made inbound call to see if there were any problems - so far so good

7) powered up ext 103
8) made inbound call, both extensions rang, I could answer each one on separate occasions everything seemed fine

9) confirmed registration on both phones showing up as public IP on ports 5060 and 6061

9) hesitantly I powered up ext 100 (at this point I'm feeling like this is a bad seed haha)
10) it didn't register
11) double checked provisioning (disabled provisioning) and set port to 5062/submit/rebooted
12) phone registeres on port 5062 but with lan ip....
13) make inbound call - extensions 100 and 101 ringing, ext 103 dialing (the number that called in)

14) punch small kitten

15) if I disconnect ext 100 the problem moves over to ext 103.

It seems like the only way to get things working "normally" again is by disconnecting all phones and restarting all services. If I simply restart all services with phones still connected the problem persists.
 
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