PHONELINE HARDWARE ANNOYANCES | Home Networking Annoyances: How to Fix the Most Annoying Things about Your Home Network

SHARING A PHONE JACK

The Annoyance:

I want to add a third computer to our two-computer phoneline network. The room where I need the computer has a phone jack, but the jack is being used by a telephone.

The Fix:

You can share the phone jack between the telephone and the computer by inserting a modular duplex jack into the wall receptacle. This nifty device, which most people refer to as a splitter, has a regular RJ11 plug on one side. Plug that in the jack. The other side has two RJ11 female connectors. Use one connector for the telephone, and the other for a length of telephone cable that you run to the new computer. Splitters are available everywhere you can buy telephone equipment, including your local supermarket.

SHARING A PHONELINE NETWORK ADAPTER

The Annoyance:

One of the computers on our phoneline network is in a bedroom without a telephone. We now want to add a telephone in that room, but the PC is monopolizing the only jack.

The Fix:

You have two methods for solving this problem:

Use a modular duplex jack as described in the previous annoyance.
Use the second connector on your phoneline network adapter.

UNDERSTANDING PHONELINE BANDWIDTH

The telephone cable that runs through your walls has multiple wires, and not all of the wires use the same frequency. When cable can contain and manage multiple frequencies, we call it broadband cable. The technical term for the broadband capacity in telephone lines is Frequency Division Multiplexing (FDM). The Plain Old Telephone Service (POTS) frequency serves any device that requires a dial tone: telephones, fax machines, and modems. Because POTS devices share the same frequency, you can't use two POTS devices at the same time.

High-speed Internet access frequency is for special devices that provide high-speed Internet access, such as DSL and ISDN devices. This is why you can use DSL and a POTS device simultaneously.

The hardware in your phoneline network uses yet another frequency to communicate. Because POTS and high-speed Internet connection devices run on their own frequencies, you can have a phoneline network, POTS services, and a high-speed Internet connection all at the same time.

Your phoneline network adapter has two jacks: one has an icon or a label for the line (the wall jack), and the other has an icon or label for a telephone. Use the line jack to connect the computer to the wall jack, and use the telephone jack for your telephone.

Line Jacks, Telephone JacksDon't Worry About the Labels

The documentation for phoneline adapters insists that you use the right jack for the right purpose: the line jack for the computer, and the phone jack for the phone.

Horsepucky!

My own experience has proven that it doesn't matter. I discovered this during the installation of a phoneline network, when I accidentally used the wrong jacks on an adapter. Everything worked fine! After that, I deliberately switched the jacks. Everything worked fine!

CHAINING COMPUTERS TOGETHER

The Annoyance:

I want to add another computer to our phoneline network, in the same room as an existing computer. The room has only one phone jack, and I'm already using a splitter to share the jack with the telephone.

The Fix:

You can attach the new computer to the existing computer, whether it's in the same room or another room. Run telephone cable from the new computer's network adapter to the second jack in the first computer's network adapter. This is called a daisy chain.

Incidentally, the fact that you can daisy-chain phoneline adapters proves the point made in the sidebar "Line Jacks, Telephone JacksDon't Worry About the Labels."

In fact, if you don't mind stringing telephone cable around the house, you can daisy-chain your entire network to one wall jack. Connect the first computer to the wall jack, and then connect the next computer to the empty jack in the first computer's network adapter. Connect the next computer to the empty jack in the second computer's network adapter, and on and on. This frees up all the other wall jacks in your house for telephones, modems, and fax machines.

Tip: A phoneline daisy chain can accommodate up to 25 computers, but no two computers on the chain can be more than 1,000 feet apart. However, I can't imagine you'd run into that problem in a home network.

USING JACKS FROM DIFFERENT PHONE LINES

The Annoyance:

One of the computers we want to put on our phoneline network is in a room with a jack. However, we wired that jack for a different telephone number. Can we still use it?

The Fix:

Sorry, all the computers on the network must operate on the same telephone line. Oh, waitI'm supposed to provide a "fix." OK then. Use the "other" wires in the jack with the different phone number. Open the jack and find the wire pair combination that matches the first phone line (you just have to match the colors). Put them into a jack (you can buy one anywhere), and connect the computer to that jack. Use your favorite Internet search engine to find one of the many web sites that illustrate do-it-yourself wiring.

TELEPHONE CABLE PROBLEMS

The Annoyance:

My phoneline network stopped exchanging data. At the same time, the telephones had a lot of static. Why would static on the phone line cause a problem with my phoneline network? I thought they didn't use the same part of the telephone lines.

The Fix:

The squirrels that chewed away the insulation on the telephone cable aren't fussy, and when they gnaw they don't go after only the wires producing a dial tone. If you don't have squirrels, substitute the same lack of discrimination for corrosive liquids that eat away the cable in underground conduits. When telephone cable has a problem, all the wires and all the frequencies on the cable share the problem. Call your telephone company for assistance.

CREATE A MINI PHONELINE NETWORK

The Annoyance:

We have an Ethernet network on the first floor of our house, and we want to add two computers on the second floor. I can't face the task of moving all that cable through the walls and rooms. Someone told me that if the rooms on the second floor have telephone jacks, I could create a phoneline network and connect it to the Ethernet network. This seems too good to be true.

The Fix:

Most things that seem too good to be true are false (ever fall for any of the stuff offered in pop-up ads?). Happily, this case is different; it's true, and it's a great solution to your problem. In addition to the network adapters for the upstairs computers, you'll have to buy a phoneline bridge. A bridge is a network device that bridges two network topologiesin this case, your Ethernet and phoneline networks. All manufacturers of network devices sell bridges, and you can expect to spend about $50.

Set up your phoneline network on the second floor by plugging both computers' network adapters into the telephone jacks. Then, on the first floor, connect the bridge to both networks. The back of the bridge has ports for each connection you need (see Figure 1-4).

Figure 1-4. Connect cables to ports to merge your phoneline network with your Ethernet network.

Connect the bridge's phoneline port to a wall jack with telephone line. Connect the bridge's LAN port to your Ethernet hub/switch/router with Ethernet cable. Read the documentation for the bridge and the Ethernet device to see whether you have to use special ports (such as an uplink port). Most phoneline bridges have an uplink port in addition to a LAN port.

Tip: You can also use a phoneline bridge to connect your phoneline network to a wireless network by connecting the bridge to a wireless access point.

PHONELINE PORTS ARE LABELED HPNA

The Annoyance:

I can't figure out which port to use to connect to the phone jack. None of my phoneline devices has a port labeled Phoneline, Phonejack, or Jack.

The Fix:

Look for a port labeled HPNA, which is the official term for a phoneline port that uses the specifications set forth by the Home Phoneline Networking Alliance. This group sets standards for phoneline networking. You can learn more about the alliance by going to its web site, http://www.homepna.org.

Tip: If you have a computerized telephone system (a PBX system), you can't run a phoneline network. The wiring into the jacks is different from the wiring in ordinary run-of-the-mill jacks, and phoneline network devices can't accommodate the differences.

EVEN UNUSED PHONE LINES CAN RUN A PHONELINE NETWORK

The rule for phoneline networks is that all the computers must be on the same phone line. If you have multiple phone numbers in your house, you have to be careful to connect all the computers to the same line.

However, the phone line you use doesn't need to be an active telephone line (a line that's been assigned a number and has a dial tone). You can use the spare telephone pair on any jack (the telephone cable has multiple pairs of lines, and a "pair" is a specific combination of colors).

As long as all the computers are connected to the same telephone pair, you can have a phoneline network. This works because the phoneline adapter doesn't use the part of the phone wire that the telephone uses. The part the adapter uses isn't connected to a dial tone.