Remote IP Phone Audio Issue

[Nicholaus Abate]

Hello Everyone,

I'm new to 3CX and VoIP and I've been creating a VoIP lab. I'm having an issue with my remote IP phone. If I dial an outside number or if an outside number calls in I cannot get any audio from that connection. If I dial an extension there is no issues. Also, to note the system running the SBC has a Windows Client Softphone running and I'm not having any issues with that.

The Remote IP Phone and the PBX are in different VLANS, but under the same public IP.

Thanks,

Nic

 

[leejor]

Does this affect outside calls to other extensions (all?), or just the one? Are you using SIP trunks? have you successfully run the 3CX Firewall checker? Is there any firewall running, on the local LAN, that could be blocking ports?

 

[Saqqara]

What phones are you using ? How have you provisioned them - manually or by dhcp 66 option / entering the provisioning url in the phone

Any port blocking between the vlans ?

Try enabling ' PBX Delivers Audio' under Options tab for the extension

 

[Nicholaus Abate]

First, thanks for the replies!!

• This affects only outside calls to and from this extension only.

• I'm using the basic setup as show in the "Basic Training" Webinar

• The PBX sits in the DMZ and there is only Windows Firewall and the built in Firewall in the Modem/Router. Rules have been created in both

• The PBX failed the firewall checker (port 5060 is being mapped to another). Like I stated above there is a rule to map 5060 to 5060 so I'm not sure why it's failing. That is the only test it fails.

• The IP phone and the SBC are in behind Firewalls and rules have been created

• I'm using Polycom SP331 ( know they are no longer supported, buts that what we had here for testing)

• there is no port blocking between these two VLANs

• I provisioned this phone first on the local LAN (using the provisioning link) then moved it to the remote network.

• Note I did try to provisioned it on the remote networking using the FQDN and the IP address of the SBC - The PBX did not see the IP Phone

• I just tried ' PBX Delivers Audio' and still nothing.

*update - that extension got a voicemail today at 10am that I made at 12pm yesterday.

 

[Saqqara]

Look at the limitations of this phone -
https://www.3cx.com/sip-phones/polycom-soundpoint-450-550-560-650-670/ stun and sbc is not supported

Very confused, on your network setup

1. Are you sure the SBC server is being used - what setup have you selected when setting up the phone in the 3CX management - considering SBC is not supported on this phone.

As you just have vlans and all ports are open - with this you just configure the phones as local lan - and use option 66 on the dhcp server

2. Wher do the firewall come into the network, as you say 'The IP phone and the SBC are in behind Firewalls and rules have been created'. Is the firewall creating the vlans ?.

3. Is there any reason 3CX server is in the DMZ ?. What ports have you opened up between the DMZ and the other networks (vlans). I would move it to your internal network and protect it via your firewall.
https://www.3cx.com/docs/manual/firewall-router-configuration/

Things to do

You need to resolve the firewall test.

Are you running the correct firmware -
https://www.3cx.com/sip-phones/polycom-soundpoint-450-550-560-650-670/

What SIP provider, has this been setup correctly

Note : Windows Client Softphone does not use the SBC, uses port 5090 direct to the 3CX server

 

[eddv123]

I have known before that using the SBC and Windows client consecutively to cause clashes, for example SIP phone will register over the SBC where client will lag.

As a test perhaps try disabling in the client "use tunnel" and have a direct SIP connection (again as a test) you will need to open the relevant ports up if you try this.

Also again as a test try disabling the Windows firewall on the PBX server as well, I would not have this on unless you are using your PBX internet facing (public IP directly on the PBX server itself).

Despite this Polycom phones are not supported in the method you are using them in, they will not work across the SBC unless you manually configure each of them and point them at the SBC (not recommended.

Either get a supported phone like a Yealink https://www.3cx.com/sip-phones/ or perhaps (if they are on the legacy list) use a VPN tunnel with DHCP Option 66 or Manually adding the provisioning link into the phones themselves: https://www.3cx.com/sip-phones/dhcp-option-66/

 

[Nicholaus Abate]

I will try to put the suggestions in place next week and run some more tests and will update.

Thanks Again