Communication between 3CX and Cisco Voice Gateway

[AAA2]

Hello All,
As am new to 3CX, am trying to connect 3CX with my office's existing cisco voice gateway with PRI connectivity and require assistance in configuraion. Cisco gateway is 2921 with VIC2-4FXO card.

Also, in 3CX do we need to create a SIP trunk or a gateway? How do we check connectivity between 3CX and voice gateway?

Trying for call flow as below

Outgoing calls:
3CX Extension(registered on 3CX) --> cisco voice gateway--> PSTN

Incoming
PSTN--> cisco voice gateway --> 3CX Extension

Thanks you

 

[leejor]

If you do some searches, on the forum. there have been a number of posts about connecting 3CX to a Cisco CME (if that is the hardware you are currently using). As I recall, none have worked correctly for all call types, even using a 3CX Bridge trunk.

https://www.3cx.com/community/threads/call-manager-express-3cx.10585/

https://www.3cx.com/community/threa...pbx-to-cisco-router-gateway-by-ip-to-ip.1487/

 

[AAA2]

If you do some searches, on the forum. there have been a number of posts about connecting 3CX to a Cisco CME (if that is the hardware you are currently using). As I recall, none have worked correctly for all call types, even using a 3CX Bridge trunk.

https://www.3cx.com/community/threads/call-manager-express-3cx.10585/

https://www.3cx.com/community/threa...pbx-to-cisco-router-gateway-by-ip-to-ip.1487/

Thanks for the reply.

I did go through the forums mentioned earlier but that only confused me more..

So it is safe to tell that interconnecting cisco gateway with 3CX does not work at all??

i don't have CME. i have CUCM registered with h323 protocol on the voice gateway. I am trying to achieve the call connectivity via sip with 3CX and if all works fine then plan to remove CUCM. So i needed to understand do i need to create a sip trunk or a gateway on 3CX? Would really appreciate if i can know the difference in any 3CX document, if any.

This is my gateway config.

voice service voip
sip

voice class codec 1
codec preference 3 g723r63 bytes 96
codec preference 4 g726r16 bytes 80

voice-port 0/0/1
no battery-reversal
timing hookflash-out 50
connection plar opx 101


dial-peer voice 20000 voip
preference 1
destination-pattern 10.
voice-class codec 1
session protocol sipv2
session target ipv4:137.116.168.147------> 3CX IP
dtmf-relay rtp-nte
no vad

dial-peer voice 10000 pots
preference 1
destination-pattern .T
port 0/0/1


sip-ua
retry invite 3
retry response 3
retry bye 3
retry cancel 3
timers expires 300000
registrar ipv4:137.116.168.147 expires 300
sip-server ipv4:137.116.168.147:5060

 

[leejor]

To allow direct dialling of 3CX extensions from the CUCM you would normally create a Master Bridge trunk in 3CX, then have a SIP trunk in the CUCM register to it.

However, there are posts specifically about 3CX and the CUCM, and most document issues, not encountered bridging some other PBXs. Some posts seem to indicate that a 3CX Generic SIP trunk may allow calls one direction, from 3CX to the CUCM, but not back to 3CX extensions

https://www.3cx.com/community/threads/help-trunk-between-3cx-and-cisco-ucm.46979/

https://www.3cx.com/community/threads/3cx-integration-with-cisco-cme.67681/

https://community.cisco.com/t5/ip-telephony-and-phones/cucm-11-5-sip-trunk-to-3cx/td-p/3043547

 

[AAA2]

To allow direct dialling of 3CX extensions from the CUCM you would normally create a Master Bridge trunk in 3CX, then have a SIP trunk in the CUCM register to it.

However, there are posts specifically about 3CX and the CUCM, and most document issues, not encountered bridging some other PBXs. Some posts seem to indicate that a 3CX Generic SIP trunk may allow calls one direction, from 3CX to the CUCM, but not back to 3CX extensions

https://www.3cx.com/community/threads/help-trunk-between-3cx-and-cisco-ucm.46979/

https://www.3cx.com/community/threads/3cx-integration-with-cisco-cme.67681/

https://community.cisco.com/t5/ip-telephony-and-phones/cucm-11-5-sip-trunk-to-3cx/td-p/3043547

Apologies if i confused you. I don't want 3CX to speak with CUCM. I only want 3CX to speak with our cisco voice gateway for PSTN access. We are having existing CUCM in our environment and planning to replace it with 3CX.

3CX server--> Voice gateway--> PSTN.

My question is how do i communicate 3CX with our Voice Gateway via SIP trunk or Adding a gateway on 3CX or a bridge?

I've also provided my voice gateway config earlier. Would really appreciate if you can check and let me know if am missing something from the voice gateway side of communication to 3CX.

Thanks

 

[cobaltit]

Wouldn't it be easier to just replace the Cisco Voice Gateway with a 3CX supported device like a Patton?

 

[AAA2]

Wouldn't it be easier to just replace the Cisco Voice Gateway with a 3CX supported device like a Patton?

Yeah i have that option but cost matters and people here are not ready for any additional hardware. As CUCM is quite expensive within its own hierarchy, they want me to replace it with 3CX which is very simple & one of the best software pbx solution.

 

[leejor]

Sorry, I was under the impression that you intended to keep the gateway working with the CUCM and wanted to bridge calls to 3CX until you could fully configure 3CX.

Not having used either myself, I can only go by the experience of others. If the Gateway can connect via SIP, then you may be able to get it to work, depending on your level of expertise, and how much time you are willing to spend on it. Again, if you search, there are a number of posts on Cisco gateways, and 3CX. While some may not be the same model, some may be similar enough that you can get an idea of what settings might allow it to work. No guarantees that it will, however.

https://www.3cx.com/community/threa...pbx-to-cisco-router-gateway-by-ip-to-ip.1487/

https://www.3cx.com/community/threads/cisco-2811-voice-gateway.20157/

https://www.3cx.com/blog/voip-howto/cisco-voip-configuration/

https://www.3cx.com/community/threads/config-for-cisco-as-a-pstn-gateway.23045/

 

[cobaltit]

Cost does matter for sure, but I assume your labor has a price. Replacing the gateway with a 3CX supported device is the clearest path forward. It would allow you to plug whatever PSTN service you have into the 3CX supported gateway, and test. If it doesn't work as expected, you swap right back.

 

[AAA2]

Thanks for the replies.

I am trying to understand the architecture of 3CX flow post installation, that would clear the hiccups logically.

 

[AAA2]

Thanks for the replies.

I am trying to understand the architecture of 3CX flow post installation, that would clear the hiccups logically.

Specially when its installed on Azure cloud. How does the communication occur between existing environment and 3CX on Cloud. Any ports need to be opened for communication? Not sure if am on right track of understanding the architecture.

 

[AWS2P]

Gateways are not usable with cloud PBX, pbx needs to be on premise.
With cloud you need an SBC on your phone use location. Only port used is 5090 when SBC

 

[AAA2]

Gateways are not usable with cloud PBX, pbx needs to be on premise.
With cloud you need an SBC on your phone use location. Only port used is 5090 when SBC

If you mean i need to create an SBC first, then a SIP trunk to my gateway with internal IP? I am thinking about the communication with my internal IP's if 3cx is on cloud. Will it work directly?

 

[AWS2P]

gateways are only supported with on premise PBX, even with SBC it's not usable.
But for sure if you have almost 2 deskphones to use then an SBC is the best and simplest choice to do

 

[AAA2]

ok so how about integrating between 3cx and my existing cucm? do i need an SBC or bridge or SIP trunk? Little confused here. Do we have any tool in 3cx where we can check the reachability of the other end?

 

[58voip]

@AAA2 we did make it by creating SIP Trunk between 3CX and CUCM. You can have a try with the guide at https://en.58voip.com/connecting-3cx-cisco-cucm/