Cisco ATA 192 routing traffic to another Router: How-To

[FS5400]

Hi everyone,

I would like to know how the ATA 192 is supposed to be configured to achieve the goal as follows:

- use it as the first device attached to ISP endpoint (ahead of my main LAN Asus one): is the bridge mode the correct one? As far I am concerned, the ISP configuration as PPPoE must be used for this purpose to get connected over the Internet, mustn't be?

- the Asus router is plugged in on the LAN port: does it need to be on the same LAN subnet only? Or is there a different set-up?

- the LAN set-up on the ATA has to bridge the ISP internet traffic as it is to the Asus router: which is the most secure way to do that? 1. static IP of the router on the LAN of the ATA 2. DMZ -> IP of the router 3. WAN set-up redirecting the traffic over the port 80 only?

Could you please even share a schema of how the network should look like?

Best Regards

[Dan Lukes]

There's no "best answer" to your question. It depends on your requirements, services and protocols you are using, features offered/supported by your ISP and features supported by ASUS router and IPv4/IPv6 addressing scheme you are using. So many unknown conditions.

As just generic blind shot - connect WAN port of ATA192 to your LAN (e.g. behind ASUS router you already have). Don't use ATA192 as router, just as ATA.

But better advice is - ask your local network administrator for help. Or someone who understand how the things works. Such expert will be able to consider your local conditions and will advice you something that will fit your requirements.

[FS5400]

Dear Mr. Lukes, Thank you for your reply. I tried this afternoon configuring the ATA behind the router as you suggested on the post. The issue I have been experiencing is that the ATA cannot get the external IP (the public IP dynamically assigned by the ISP). 0. On the router the SIP ALG is disabled and the port forwarding is enabled for port 5061 over UDP protocol as provided by ISP VoIP line parameters. Moreover, I have assigned a reserved local network IP for ATA on DHCP settings. The ISP credentials are set here and I can access the Internet and the ATA configuration portal to its IP behind the router with no issues.1. The ATA is acting in NAT (instead of bridge) mode. As network settings below the main:
- Network Setup > IPv4 Settings > Connection Type: here I have Automatic Configuration - DHCP. Is that correct?
- Network Setup > IPv4 Settings > DNS Server Order: DHCP - Manual
- Network Setup > Advanced Settings > VLAN: VLAN enabled and value set 1036
2. The ISP is using IPv4 and it is Vodafone Italy broadband network via FTTH. Below you find the parameters: 
- DNS SRV query: enabled -> parameter found and configured accordingly. LINE 1 > Proxy and Registration > Use DNS SRV: YES.

- Packetization Time: 20ms -> parameter found and configured accordingly. LINE 1 > RTP Parameters > Packet Size: 0.020. Is also RTP Tx Packet Size Follows Remote SDP to be kept YES (default)?
- Expire Time: 3600 -> parameter found and configured accordingly
- DSCP Marking (decimale): 34 -> Could not find this parameter? Any clue?
- Register fetch/Fetching bindings: NO -> Could not find this parameter? Any clue?
- DTMF: AVT (RFC 2833), InBand, SIP INFO -> parameter found and configured accordingly. LINE 1 > AUDIO CONFIGURATION > DTMF Process AVT/INFO set to YES. DTMF Tx Mode: BAND + INFO

- VAD (Voice Activity Detection): non presente -> Could not find this parameter? Any clue?
- 100rel support (PRACK) RFC3262: enabled -> parameter found and configured accordingly. LINE 1 > SIP Settings > SIP 100REL Enable: YES

- Supporto UPDATE (RFC3311): enabled -> looks enabled by default. It should be OK
3. Use Local Addr In From: Is this parameter not using the external IP received from the router? Or is this nothing to do with the error obtaining the ISP public IP? What could you suggest to fix this issue? Even though what I have reported is barely correct, please help me figuring out what is the few parameters Unfortunately, I do not have a network admin as I am using the device within my house and I realized too late for giving it back. I am aware that this product fit small business companies better, but I cannot do anything than sorting it out somehow hopefully with some help of the community.Best regards