Celebrate National IT Professionals Day with 3 months of free Premium Membership. Use Code ITDAY17

x
?
Solved

Connect Speed (line vs. port)

Posted on 1998-12-31
14
Medium Priority
?
322 Views
Last Modified: 2013-12-27
When connecting to the net with my 3 Com PCI WinModem, the reported connect speed is usually the line speed (e.g. 33600 bps) as expected.  But sometimes, it is the port speed (e.g. 115200 bps) that is reported.  Can you tell me why this happens and what to do to fix it
0
Comment
Question by:lennyh
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 5
  • 4
  • 4
  • +1
14 Comments
 
LVL 3

Accepted Solution

by:
trath earned 280 total points
ID: 1146332
This is a driver problem. The only way to fix it is to go to the 3com website and download the newest driver for your modem. Even if you have only had your modem for 2 days chances are great that there is a updated driver for your modem.

The address is...
http://www.usr.com/home/online/

choose diver .inf files and find you modem. downlaod and install the driver.
0
 
LVL 3

Expert Comment

by:trath
ID: 1146333
Sorry. Or choose Upgrades/Updates I'm not really sure since US Robotics bought out 3Com
0
 

Author Comment

by:lennyh
ID: 1146334
trath, thank you for your response.  I checked the website, but it wasn't clear that any of the updates were associated w/ my modem.  I sent a note to 3-com.  We'll see if they have anything to say.

Interestingly enough, I have buddies w/ other modems/systems that experience similar connect-speed-reporting anomolies.
0
VIDEO: THE CONCERTO CLOUD FOR HEALTHCARE

Modern healthcare requires a modern cloud. View this brief video to understand how the Concerto Cloud for Healthcare can help your organization.

 
LVL 3

Expert Comment

by:trath
ID: 1146335
Also even though it may say 115200 that doesent mean anything. You connection speed should still be 53***k. The 115200 is the fastest that the windows port recognizes, which is 28,800, because that is the port speed without a compression algorythm.
basicly anything below 28,800 uses no compression Everthing above it does, so your windows is recognizing the actual port speed only, but as long as you have the "use compression" box checked in modem properties you are still connecting at 56k. So

Its a pain but I wouldnt worry about it, its really not w
0
 
LVL 3

Expert Comment

by:trath
ID: 1146336
Sorry didnt complete my thought....
0
 
LVL 3

Expert Comment

by:vikiing
ID: 1146337
Basically, there are three links when you connect to a remote computer:

   Your Computer <--> Your modem <--------> Their modem <--> Their computer


One link is between your computer and your modem, one between the two modems, and one between their modem and their computer. What might surprise you is that each of these three rates can be, and often are, completely different. So you know, DCE stands for Data Communications Equipment (i.e. a modem to modem link) and DTE is Data Terminal Equipment (i.e. terminal to modem link). You are not concerned with the final link, the remote DTE rate. That is up to the  remote site, and does not matter at all to you. Once the data leaves your modem, and is received by theirs, it is out of your hands.

Thus, your DTE speed can be 115200, while DCE link runs at 56K; of course the MAXIMUM speed of THE WHOLE thing you can achieve will be the MINIMUM of the 3 links; if you have a modem running at 14,400 bauds, you'll never get a connection faster than that, no matter the other extreme has a 28, 33 or 56K.





The link between your computer and your modem is

               DTE rate           DCE rate            DTE rate
                38,400             14,400              57,600


0
 
LVL 3

Expert Comment

by:vikiing
ID: 1146338
Opps !!, I left a final line saying "the communication speed will be as faster as 14.4k".
0
 

Author Comment

by:lennyh
ID: 1146339
vikiing, thanks for your response.

I am familiar with the distinction between port speed and line speed.  What I'm puzzled about is why, on only some occasions, the connect speed reported by the modem is the port speed rather than the line speed and what can be done to fix this  In the past, I've tried adding extra AT sequences to the modem string w/o avail.
0
 
LVL 3

Expert Comment

by:vikiing
ID: 1146340
There are a couple of AT commands (some modem don't recognize them) that tells the modem to inform one speed or the other.

When you receive CONNECT XXXX, that "XXXX" can be line or port speed, depending on how the modem is set. You should read your modem's manual to see if it has something like that.

Just only as an example, Zoltrix modems report DCE speed with an ATW2 command; on the other hand, ATW0 (zero) makes modem to report DTE speed instead.
0
 

Author Comment

by:lennyh
ID: 1146341
Thanks for your response.

Perhaps I didn't make myself clear.  Most all the time, the line speed is properly reported as the connect speed.  Only sometimes is the port speed reported as the connect speed. So my questions are: What is it that causes this to happen and how can it be remedied?
0
 
LVL 3

Expert Comment

by:vikiing
ID: 1146342
Parhaps modem is set in different modes depending on the different software packages you use, i.e., a fax program can set modem to report DCE speed, and a terminal program initializes it to show DTE speed.

What is sure: if you use ATZ command, modem will be set at the same state. Thus, CONNECT must show ALWAYS the same value, be it DCE or DTE (but not DCE now and DTE tomorrow in a random scheme).

How to remedy?, that's depends on what is the command your modem uses to specify one report or the other.
0
 

Author Comment

by:lennyh
ID: 1146343
Vikiing, thanks for your response.

I understand your comments regarding the different applications.  In this case, however, the variablitlity in reported connect speed occurs in the same application - my DUN internet dialer.  Lauching the dialer usually results in the line speed (DCE) being reported as connect speed. But once in a while, launching the dialer results in the port speed (DTE) being reported as the connect speed. ??


0
 
LVL 3

Expert Comment

by:vikiing
ID: 1146344
As I've said over there: computers are living creatures... :) :)

0
 
LVL 1

Expert Comment

by:Moondancer
ID: 6875617
GREETINGS!

This question was awarded, but never cleared due to the JSP-500 errors of that time.  It was "stuck" against userID -1 versus the intended expert whom you awarded.  This corrects the problem and the expert will now receive these points; points verified.

Please click on your Member Profile and select "View Question History" to navigate through any open or locked questions you may have to update and finalize them.  If you are an EE Pro user, you can also choose Power Search to find all your open questions.

This is the Community Support link, if help is needed, along with the link to All Topics which reflects many TAs recently added.  Also in the Community Support link is a question on how experts can help, if they wish, on the cleaning of old and abandoned questions.

http://www.experts-exchange.com/jsp/qList.jsp?ta=commspt
http://www.experts-exchange.com/jsp/zonesAll.jsp
 
Thank you,
Moondancer
Moderator @ Experts Exchange
0

Featured Post

Will your db performance match your db growth?

In Percona’s white paper “Performance at Scale: Keeping Your Database on Its Toes,” we take a high-level approach to what you need to think about when planning for database scalability.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

In this tutorial I will show you with short command examples how to obtain a packet footprint of all traffic flowing thru your Juniper device running ScreenOS. I do not know the exact firmware requirement, but I think the fprofile command is availab…
This article will show how Aten was able to supply easy management and control for Artear's video walls and wide range display configurations of their newsroom.
This course is ideal for IT System Administrators working with VMware vSphere and its associated products in their company infrastructure. This course teaches you how to install and maintain this virtualization technology to store data, prevent vuln…
Have you created a query with information for a calendar? ... and then, abra-cadabra, the calendar is done?! I am going to show you how to make that happen. Visualize your data!  ... really see it To use the code to create a calendar from a q…
Suggested Courses

730 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question