Modems And Connections Essay Research Paper The

Modems And Connections Essay, Research Paper

The issues discussed here often overlook the very basic things you need to get a modem connection – if you’ve never used a modem, or you are doing a new installation, you may want to seek more basic help and troubleshooting information first. There are MANY factors that affect modem connection speed. A 33.6 modem will rarely get 33.6 connections (it requires a very clean line and clean routing to the server modem); 28.8 and 26.4 are more common. Similarly, a 56k modem will rarely get 56k – most people are getting 42-49.3k; a lucky few are getting rates in the low to mid-50’s. The large group that is getting no 56k, or rates below 40k is the focus here. Low (*40k) rates can indicate a digital impairment that is not correctly compensated for by modem firmware. It can also be related to the quality of your modem and premises telephone wiring. Other devices (phones, answering machines, fax, etc.) plugged in to the same line (even though not in use) can also cause lower speeds. If the impairment is at the ISP or specific to the routing to that ISP, you may be able to get higher rates calling other #s (ISPs). And problems can also be related to the type of equipment and firmware in the modems you are calling.

The way many of us use modems has changed dramatically in the last few years: Today, the vast majority of our connections are to a single local ISP access number as opposed to calling many (local and toll) BBS and information providers. Effective troubleshooting must isolate the problem, and part of my approach calls for checking connections with as many servers as possible.

As used herein, 56k refers to dial-up modems operating faster than v.34 rates. V.34 allows up to 33.6k connections (although 33.6 is rare; 28.8 is the more common maximum you will get with v.34). The lowest Flex, x2 and V.90 rate is 28000 (most 56k modems will not connect at a lower than 32k initial rate before reverting to a v.34 connection). And before you start with the steps below, make sure you have your modem installed correctly, and set the port speed (”maximum speed” in Control Panel-*Modems-*Properties) to 57,600 or 115,200.

Call Waiting & Your Modem

Many of today’s modems can recover from significant line noise hits – including the call waiting tone that you may get if you have the call waiting feature on your line.

If you have call waiting, in most areas, you are able to disable it prior to placing a call by dialing a code (usually *70) before dialing your ISP’s number. If a person tries to call you while you are on the net, they will get a busy signal.

If you don’t disable call waiting and your modem doesn’t disconnect on the call waiting tone, the caller will hear your phone ringing and ringing and ringing.

You might be able to get your modem to disconnect on call waiting tone by lowering the modems disconnect on loss of carrier register. Consult your modem documentation for the register and values. Most modems use S10 for the disconnect on loss of carrier with a value of 7(msec); you could try a lower value (down to 1) by adding s10=# in extra settings. Similarly, if you’re getting bumped when a call comes in and you want the modem to stay connected, you would increase the value.

What’s a 56k-compatible line. (New 2-Mar-99)

One of the requirements listed on at least one brand of 56k modems is “A 56k-compatible line” – without defining what such a line is.

Pretty slick. It’s true that some telephone lines/facilities will prevent 56k from working, but there is no way for the average member to easily determine whether his line is ‘56k-compatible’!

If you get a 56k modem, and you get 56k connections, you can safely say that you (presently) have a 56k-compatible line. However, if you don’t get 56k connections, you cannot correctly assume that your line is not ‘56k-compatible’.

Possible reasons for not getting a 56k connect can include:

The firmware in your modem isn’t working properly for your line conditions

The firmware in your modem isn’t ‘compatible’ with the firmware in the server modem you are calling

The firmware in one of the modems isn’t ‘compatible’ with the digital portion of the telephone network being used

Your line is not ‘56k-compatible’

In some of the above circumstances, you would be able to achieve a 56k connect with a different modem, or calling a different V.90 server.

56k Modem manufacturers have generally defined a ‘56k-compatible line’ as being one that has only 1 D/A conversion (or 1 A/D conversion), and your local loop is less than 3. miles. You may be able to get an answer – not always correct – if you ask your telco for the loop length and if your line has more than 1 A/D conversion. There is no ‘requirement’ or standard procedure for getting this information from a telco. But, even if you find you have only 1 A/D conversion (a ‘56k-compatible line’), you may still not be able to get a 56k connect with any 56k modem if your telco introduces certain types of digital impairments.

What 56k Connect Rate Should You Expect.

56k Modems rarely connect close to 56k. In the US, FCC-imposed power give most 56k modems a maximum potential for a 53.3k connection. This was supposedly lifted for V.90 modems now that an international standard is out an

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