Modem Troubleshooting - Introduction

Modem Troubleshooting INTRODUCTION

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. (See the access numbers page.)

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.