Rebooting Motorola VT1000v

Posts: 10 · Vonage Forum Associate Joined: Feb 12, 2004 Posts: 10

Diamer:

Here's how I understand it:

If you turn off NAT in the vt1000, it can't serve as a gateway for anything behind it. Once NAT is turned off in the vt1000, it can only be accessed by directly connecting a pc to its LAN port. To communicate with the vt1000 the pc would have to have a fixed ip address of 192.168.102.2. Since there is no NAT in the vt1000 however, the vt1000 could not translate the 192.168.102.2 address to something that could be passed to the internet. (192.168.x.x is a private subnet that can't be externally routed without Network Address Translation.)

If you turn off NAT on the MTA, (and the MTA is in front of the router) it is either going to get an external ip address through dhcp or you have to assign it the one static ip address you have received from your broadband provider. Assuming you give the MTA the static ip address, then the router is going to have to get its external ip address through dhcp. Now you have two independent devices with two independent external ip addresses. Neither device would be serving as a gateway for the other. In this setup, if your pc is behind the router, then the router is going to be providing NAT for the pc and the pc's ip address will be within the router's private subnet. The private address of the router would serve as the gateway address for the pc.

To help visualize all this you could think of it this way: With NAT turned off on the MTA and the MTA in front of the router, it is almost like there are two independent channels coming from the cable modem into your network. One line runs to the MTA, the other runs to the router.

If you turn NAT on in the MTA, then there is a single channel running from the cable modem to the MTA and from the MTA to the router. In this setup the MTA assigns the router an address in the MTA's private subnet.

You also have the option of placing the MTA behind the router. In this setup the router can be given the static external ip address you have received from your broadband provider, and then the pc and the MTA (both behind the router) will receive addresses within the router's private subnet.

The no NAT mode isn't documented, and we've been floundering around quite a bit as a result!

Posts: 1 · New Forum Member Joined: Nov 11, 2004 Posts: 1

Quote:

You can leave the ATA between your cable modem and your router. Just disable NAT/DHCP on the ATA (put in in pass-trough mode) and let your router manage the Internet traffic. I have not had a single problem with my ATA since I did this. My calls quality is also better with this setup since it provides QoS.

From Vonage support:

Quote:

In regards to your question about QoS and NAT, if you have disabled NAT, you are disabling the feature of the device to function as a router which will disable QoS.

-- so who has it correct?

Posts: 66 · Full Forum Member Joined: Dec 15, 2003 Posts: 66

Quote:

From Vonage support:

In regards to your question about QoS and NAT, if you have disabled NAT, you are disabling the feature of the device to function as a router which will disable QoS.

Eh?

-- so who has it correct?

I think the Vonage guy is wrong. I currenly use my Moto VT1005 with NAT turned off. The Moto gets one public address and my D-Link router plugged into the Moto gets another (my ISP will provide 2 IP addresses). I was getting bad outbound voice quality before when I had the Moto inside of my router. Since going to the current config as described above, outbound voice quality is much better during high-bandwidth uploads. I think the QOS (for outbound voice only) works regardless of the Moto config.

The downside of all this is that neither the Moto nor Vonage can do anything about inbound voice quality. If you are doing a high-bandwidth download, you may hear severe inbound voice distortion or loss.

Bob

Posts: 66 · Full Forum Member Joined: Dec 15, 2003 Posts: 66

Here's my physical config:

Internet -> Moto -> D-Link router -> PC1,PC2