Changing IP address of connections from AWS towards SIP

[vichar]

Hello all,

We have installed a PBX on AWS and connected it to our on-prem Router via VPN.

My on-prem router is connected to the SIP provider via another on-prem MUX device.

All connections are working fine, EXCEPT, my SIP provider has a condition that all connections to their server must originate from a specific IP that they have assigned to us.

Since AWS machine is connected via VPN, all calls from PBX are picking up the IP of the AWS machine.

For resolving this, i need to change the IPs of all connections from AWS to SIP.
Someone suggested i need NAT loopback/reflection for this.

Please guide how can this be done?

Regards.

[balaji.bandi]

In your case, ask for some reserved IP from AWS, give those IP address to SIP provider, For your PBX IP do static NAT with that Public IP.

https://docs.aws.amazon.com/vpc/latest/userguide/VPC_NAT_Instance.html

[vichar]

Thanks Balaji. 

However, that is already tried. The SIP provider will allow communications only from the IP that they have provided. 

[balaji.bandi]

Is that IP routed to your network ?  Still i try to get my head around,

[vichar]

It is a private IP assigned to their MUX device which is installed in our premises. We have connected it to our cisco router's WAN port and assigned WAN IP with the same one. 

[balaji.bandi]

what is the issue now then ?

[vichar]

The issue is, when calls generate from the PBX in AWS, it's taking the IP of the AWS machine to the SIP provider. 

What we require is NATing / Changing the IP of all communications generating from AWS machine, to the IP provided by SIP. 

[balaji.bandi]

We need to understand how is your setup and routing, AWS to internet and MUX to provider.

Do you have any HLd diagram,  how are you peering with SIP provider, is the MUX also located in AWS or onsite ?

[vichar]

[balaji.bandi]

Where the calls originating from ? If the calls originating from Client, you need make routing decision for that calls to send to MUX- in RV042.

[vichar]

All outgoing calls are originating from PBX. clients will communicate with pbx via internet and call will generate from pbx. And from pbx will go via vpn to cisco rv042, and then to mux, and then to sip provider from where will connect to external number. 

Someone suggested packet forwarding for replacing AWS IP to mux ip in on-prem environment (maybe via a router or a firewall software). Does it make sense? What is your suggestion, if otherwise.