Setting up remote viewing when you have multiple routers

How do I know my network has more than one router, and what do I do?

Many people who have a multiple-router network aren't even aware of it ... until they try to set up their Slingbox. As home networking equipment increases in popularity, it's becoming more common to find home networks that have more than one router.

For example, some DSL modems already have built-in routers, so if you connect another router-equipped device to the network, it then has two routers. If you install a VoIP phone adapter (such as Vonage or AT&T Digital Phone Service) you have two routers in this case as well.

It's important to determine which router is the primary one: it's the one that is closest to a connection to the "outside world." Usually that means that the primary router is:

• connected directly to either a DSL or cable modem, or

• connected directly to the telephone line or cable entry point into your home.

If there's any other device connected to your home network that identifies itself as a "router" (check the manufacturer's label, probably on the bottom or the back of the unit) then you have a multiple-router network. In that case, for your Slingbox to work outside of your home, you must find every router between your Slingbox and "the outside world," and configure each one so that it works with your Slingbox.

The following sections contain background information that you might find helpful as you work on this:

A router designed for home networking serves several important purposes:

• it contains a firewall, which is built-in hardware and software that helps protect your network from outside intrusions

• it often (but not always) has multiple ethernet connections in the back, which gives you a physical way to connect more than one computer

• it coordinates network communications within your home network

• it coordinates the communications between your home network and the Internet (outside of your home network)

Your router has a dual personality; it acts one way to everything outside your home network, and another way to everything inside your home network.

Outside your home network, to your Internet Service Provider (ISP), a router appears to be a single computer ... just as if you'd connected your computer directly to your DSL/cable modem. You can have many computers/devices connected to your router, but to your ISP, you're only using one computer. Your router does that by gathering the individual data streams from each of your computers/devices, then presenting them to your ISP as a single data stream. With a router, you can connect multiple computers to the Internet ... while only paying for one Internet connection.

Inside your home network, the router keeps track of which data goes to which computer/device. Just as it collects outgoing data into a single data stream, it also sorts out incoming data and determines which computer/device the incoming data is intended for. In this way, it makes it seem to each computer/device like it has its own connection to the Internet. The router also connects each computer/device within your network, so they can communicate with each other.

To the Internet and outside world, the router identifies itself using a Public IP address. This public IP address, usually provided by your ISP, is unique throughout the world. An IP address consists of four groups of one-, two-, or three-digit numbers, each separated by a period. For example, 12.34.56.78, or 123.45.6.789. The Gateway address is the IP address of the remote computer (at your ISP) that your computer is connecting to. The gateway address is almost always your IP address with "1" at the end. So if your IP address is 123.45.6.789, your gateway address is very likely to be 123.45.6.1.

Inside your network, the router distributes an internal-use only Private IP address to each of the computers/devices that are connected to your network. Routers of the same brand all use the same private IP address numbers, but it doesn't matter: private IP addresses never go outside of your internal network. Your computers can access the Internet, and each one thinks it has a unique IP address. (Computers won't share IP addresses, but they can only tell if another computer/device is using the same IP address within the same network.)

Finally, ports help a router control access by blocking some data streams while allowing other, very specific streams. Ports aren't actual hardware connections, they're "virtual" entry points within the router's software. They can be specified as part of a URL. For example, in the URL 192.168.1.201:5001, the part after the colon (5001) is the port number. Ports can be "opened" or "closed" as needed. If they're open, they're often programmed to allow only a specific type of network traffic through, and only for a specific purpose.

The Slingbox uses port 5001 when it communicates with your router, so this port needs to be open for your Slingbox to send video outside of your network.

If possible, it's much easier to connect the Slingbox to the primary router, as shown below. That way, you only need to configure that one router (the primary router):

The following diagram is an example of a network in which the Slingbox connected to a router other than the primary one:

While it is much easier to connect the Slingbox to the primary router, in some cases, that isn't feasible (for example, if the Slingbox and the primary router are in different rooms and you're not using a SlingLink or other powerline device to connect the primary router to the Slingbox).

The rest of this article describes how to configure multiple routers so your Slingbox can work outside of your network. But first, here's some terminology that you'll need to know:

You'll use two steps to set up your two-router network for your Slingbox:

• Configure your primary router, which includes assigning an IP address to the secondary router and opening port 5001;

• Configure your secondary router, which includes using the IP address you assigned to the secondary router in step 1, and then opening port 5001.

First: Set up the primary router

1. Open a browser window and access your primary router's configuration screen. (See your primary router's user guide if you are unsure how to do this.)

2. Enter the appropriate username and password, if prompted. (Some routers use a password only, with no username. Check your router's documentation for more information.)

3. The router's setup/configuration screens display in the browser. If you haven't changed the router's default password, this might be a good time to change it! Keeping the manufacturer's default password is a security risk. IMPORTANT: If you do change the password, be sure to make a note of it so you'll be able to find it when you need it.

4. Find the configuration screen where you can assign IP addresses to particular devices within your network (see your router manufacturer's documentation and/or website if you're unsure how to do this). If possible, assign a fixed IP address to your secondary router. (See Important Note at the end of this article). If the primary router needs a MAC Address for the secondary router (this has nothing to do with Apple Macintosh computers) you can probably find the secondary router's IP address on the bottom of its case. If not, see its documentation for more information.

5. Browse the primary router's configuration screens for a section that involves "Port Forwarding" or "Open/Close Ports."

6. Open port 5001 for the IP address you assigned to the secondary router in the previous step.

You're done with the primary router.

Next: Set up the secondary router

1. Open a Web browser window, and access your secondary router's configuration screen, similarly to the way that you did for the primary router.

2. Enter the appropriate username and password, if prompted. The router's setup/configuration screens display in the browser.

3. Find the secondary router's configuration/setup screens for a section that involves the IP address or "Public IP address" that the secondary router receives externally. Normally, you would configure the router to communicate with your ISP, but in this case, you're configuring the secondary router to communicate with the primary router. You will probably need to change the type of IP address that the secondary router receives from DHCP (or "dynamic" IP) to static IP.

4. Enter the IP address that you assigned to the secondary router in step 4. For "Gateway," enter the IP address again from the step above, except change the last number group to "1." For example, for the secondary router 192.168.1.101, the Gateway address is 192.168.1.1. You may also need to fill in values for DNS Server. These values would be the same as for your primary router. Check with your ISP for information on what to enter here.

5. Browse the primary router's configuration screens for a section that involves "Port Forwarding" or "Open/Close Ports."

6. Open port 5001 for the IP address you assigned to the Slingbox.

For example, here's what the Linksys setup page might look like if a device with an IP address of 192.168.1.237 has port 5001 opened:

After you've done this, you're done with this setup procedure.

The best source of information about configuring your primary and/or your secondary router is the documentation that came with the router(s). You might also contact the router manufacturers' websites for more information. Contact Sling Media Technical Support if you have questions about configuring your Slingbox.

Important note about static versus dynamic IP addresses for the secondary router: Setting a static, or permanent, IP address for your secondary router can save a lot of headaches. Otherwise, your primary router will eventually assign to your secondary router an IP address that's different from the one that you used in these steps. When this happens, Slingbox remote viewing will stop working outside of your network. You'll have to reconfigure your secondary router with whatever new IP address that your primary router has assigned ... and keep doing that each time the secondary router is assigned a new IP address by the primary router.