Connecting DSL Modem to Wireless Router

[anubo]

Hi,

I have a problem with the connection between my DSL Modem (Thomson Speedtouch 706) and wirless router ( DLink DIR-655). I use a PPOE connection,

My DSL modem also had a port for VOIP.

The problem I have is that if my modem connects to the internet using my username and pass all will work but i will have to connect my pc directly to the modem as there will not be any internet from the router.

If is press the disconnect button is the Modem setup page then the VOIP will not work on the modem but the router can access the internet.

Basically I know that only one of them must connect to the internet. What i need to know is how to make my Wireless Router us the connection that the modem had established.

Thanks for your help but I am a bt green with this.

[Cavalier90]

Is a combined router/modem not an option? This is far simpler to sort out and retains internet connection as the login details are in the router.

If I'm not mistaken, if you keep separate units the modem will have to be plugged into a PC (to allow login details to be provided) then other computers on the network access the internet via the router and the PC as a shared device.

[Variable]

On the cable modem you can either use the range that is currently set up or change it. For clarity I will assume you change it but, this gives you an idea of what you need to do. On the modem, assign the LAN side a 192.168.100.1 addess, dunno about the voip setup but you may have to change the DHCP range to 192.168.100.10-192.168.100.150. Statically assign the LAN side modem IP to 192.168.100.1 mask 255.255.255.0. Assign the same DNS servers as you currently use.

Connect to the router, assign the WAN side IP as 192.168.100.2. Gateway would be 192.168.100.1. Assign the LAN side of the router 10.0.0.1 mask 255.255.255.0 with a DHCP lease range of 10.0.0.10-10.0.0.50, gateway would be 10.0.0.1. Assign the same DNS servers as you currently use. Save settings.

On your PC, disable and reenable the NIC. Right click My Network Places, right click your Local Area Connection, disable, then enable.

Your machine should get a new IP in the 10.1.1.10-50 range. Verify connection. The modem is also a router, you have two routers. You need to separate the networks. The modem will give VOIP packets priority.

[classicsoftware]

For this to work, you need to go into the router's firmware and set it for PPPoE and add the user name and password so the system will connect. If your modem also serves as a router, you will need to contact your ISP for instructions to put it in bridge mode so it will serve as modem only.

[anubo]

Ok thanks I will try it out once I am home.

Thanks again

[Variable]

This is probably incorrect. If the modem is the VOIP device as stated, putting it in bridge mode will probably break VOIP.

[classicsoftware]

You can't have two routers. The reason why he can't connect with the router plugged in is the router is not reporting the user name and password as is required with PPPoE. I also suggested he speak with his ISP who would (I hope) not let him place it in bridge mode if that would zap the VoIP.

[Variable]

Sure you can have two routers, you could have as many routers as you want, as long as they are on different networks, this is what the internet is made of. The problem is the devices need to have separate networks on each side, LAN and WAN. The modem does the PPPoE and the router simply hangs off one ethernet port. The problem is likely the two devices have a default LAN DHCP assignment in the same range. If he had a different router it would probably work plug and play.

[classicsoftware]

Sure you can have two routers, you could have as many routers as you want, as long as they are on different networks, this is what the internet is made of.
But he does not have two different networks. he only has one. He would have to have a nic for each.

The problem is the devices need to have separate networks on each side, LAN and WAN. The modem does the PPPoE and the router simply hangs off one ethernet port. The problem is likely the two devices have a default LAN DHCP assignment in the same range. If he had a different router it would probably work plug and play.

In my experience, it does not work that way with PPPoE. You need a user name and password and that is either supplied by the router or the software provided by the ISP. The Telco's around me do not have modems that hold the user name and password.

We'll just have to wait for the ISP to see what is setup actually is....

[Variable]

But he does not have two different networks. he only has one. He would have to have a nic for each

Nope, the networks are defined by the routers. You would only need two Nics if one end point device was on both networks. The modem is a router if it is doing VOIP. He needs two different networks for it to work. So one network for the Modem LAN side and VOIP devices and one network for devices connected to the wireless router.

Now, if he needed wireless end points to connect over VOIP he has a problem. Several in fact. VOIP and encryption is a bad combo unless, you have a lot of throughput and speedy routers. VOIP tags the packets, you have to have a device that recognizes the tagged packets. This is done through VLANS which is done at the switch level. Many consumer grade routers also do VLANS now. So it is possible that this could be done on the wireless router. You would create VLAN 1 for tagged (VOIP) and VLAN 2 (Data) for untagged. You place one physical port in both VLANS. You set up up the same VLANS on the modem or more likely, look at the modem configuration and match that on the wireless router. Tagging and QOS is required for VOIP in a mixed data/voice network. I am intimately familiar with this having set up and troubleshooted several of them now.

In my experience, it does not work that way with PPPoE. You need a user name and password and that is either supplied by the router or the software provided by the ISP. The Telco's around me do not have modems that hold the user name and password

PPPoE is just a method of authentication/encapsulation. You need the modem to connect with PPPoE, if the modem does VOIP and you want to keep this functionality. The wireless router needs to have the WAN side on the same network as the modem and the LAN side of the wireless router needs to be a different network for routing to take place. You cannot put the modem in bridging and have it also do VOIP. VOIP will require routing and priority features. VOIP uses QOS (Quality of Service) to ensure VOIP packets are given higher priority than other data packets.

When I first read the orginal post I typed pretty much what you did, then I read it again and saw that VOIP was on the modem. That changed everything. I deleted my entire post and put in new instructions.