About 56k Modems

Disconnections from the Internet and Other 56k Issues

The issues surrounding frequent disconnections from the Internet when using a56k modem are not unusual. 56KB modems are discussed in great detail on all thenews groups and are a general discussion of most ISPs. The facts are that 56KBmodems are generally less reliable than its older V.34 counterpart. In order foryou or anyone with any ISP to establish a reliable 56k connection is dependenton many items. We have seen a general upgrade in most customers speeds andconnection reliability as V.90 firmware has evolved. We continue to upgrade ourV.90 code as the industry and standards evolve.

cheap hotels in WarsawThe issues with reliability are usually one or more of the following issues:

1. Modem and Modem Firmware

2. Phone line

3. Phone line interference or padding devices

1. Most modems (even brand new) come with a version of V.90 code which wasdeveloped based on certain standards when initial engineering of the modembegan. V.90 has been changed substantially. Most modem manufactures offerfrequent changes to their firmware as standards change and bugs are identified.We suggest you update your modem firmware to have the most stable and reliableconnections possible.

There are two main types of modems on the market. Hardware and software basedmodems. Software based modems are by far the most frequently sold modems. Theyclaim many great things, such as, you will never have to upgrade them, insteadjust download the latest updates. These software modems use a modem card thathas less chips on it and therefore costs less to make and sell. The costbenefits are far outweighed by the reliability and speed issues with thesemodems. The actual communications, error correction and compression, plusV.8-V.90 codes all happen within your CPU. Many modems can tax your CPU to amuch greater extent than a hardware modem (some software modems or WinModem as3COM calls them, are better than others). One fact about software modems isthat, if your system is not working perfectly or you are running heavyapplications, such as graphical games, your connections are going to be muchless reliable.

2. Phones line are completely out of the control of ACS Online. They are avery frequent cause of disconnections. The main problem is that phone linequality is changing all the time. Your modem should respond to the changes andslow down and or ask the other modem to resend information not properlyreceived. This is the function of error correction. Many 56Kb modems willdisconnect as phone line problems get worse, instead of slowing down. A firmwareupdate for your modem may help. 56KB technology (V.90, kflex, X2) all rely onthe same phone line elements. They require no more than one analog to digitalconversion. These A/D conversions happen between your line and US West's mainswitch. Unfortunately as new subdivision and new phone services are added to thearea, US West can and does change the routes to and from certain houses.Basically they change the switch or switches you go through. If you have morethan one A/D conversion you will either see slow speeds or disconnects. You donot generally have any control over this part of the connection. Most phonecompanies not very receptive to making changes to benefit data communications.

3. Padding devices are products applied to a line that cause lines to behavedifferently. A common padding device is used by US West to clean phone linebuzzes. It is placed on your subdivisions phone connection or house. There areseveral other padding devices that they use. One padding device that you use isa caller Id box. Caller Id takes two parts, first US West needs to set up theservice for you on your line and second you attach the device to your line.Caller ID is a common problem for 56KB modems. The technical reason is asfollows. Telcos use either RBS (Robbed bit signaling) or SS7 (Signal System 7)to achieve caller id. In either case the basics are to take one bit per 6 8bitsamples and transmit caller id info. Your 56KB modem assumes that all bits arefor its use and many will disconnect when RBS or SS7 are present on the line.The caller ID box itself can be the problem. They are in fact a padding devicethat take power off the line, plus they have a signal on the line looking forRBS/SS7 information. We have had several cases where users unplugged therecaller id and stopped getting disconnected, although in a perfect world youwouldn't have the signaling on the line either.

The more phones or phone line devices (answering machines) you have on theline, the less power is available for communications as well. Again in a perfectworld you would reduce your number of devices down to your computer.

In troubleshooting disconnection problems, our suggestion would be to upgradeyour modems firmware to the latest code available. Unplug all of your phone linedevices including caller id, answering machines and phones, then try yourconnections again. See if that helps. If not, my suggestion would be to put inyour extra settings the AT commands necessary to achieve a v.34 connection. Thiswill generally fix any issues.

If this doesn't fix the problem either, we would suggest a different modem.

Alojamiento en posada/pension/parador MikonosOur connections to US West are via T1-Pri lines and are monitoredconsistently for problems. US West has certainly had some issues over the years;however they are not very often or for very long. Our system is currently atless than one half capacity and our bandwidth is presently fairly low with a lotof growth room. We have updated our V.90 code regularly as reliable updates areavailable. Any speed issues as far as throughput are concerned are verydifficult to monitor.  Unfortunately using any TCP level monitoring to seethroughput will give you false readings. If you want to get a pretty good metricof speed, download a 1mb file from the same source 10 times a 10 different timeperiods, then do it again from another source. Divide and average and this willbe a pretty close metric of speed. If you were to do this with a different ISPor at a different time period with us, you could figure out some issue withspeed. The reporting happening on your IE or Netscape browser is based on TCPfeed back and then a mathematical guess by the browser, which is why the finishtimes are never correct.

 If you have any questions please call or office or direct them by email to: support@acsol.net