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MarkN
Tl Posts:
5

USA
Posted - 3/25/2002 11:31:59 PM  Show Profile  Email Poster  Edit Message
I’m looking for a new ISP and have been dialing in to various ISPs servers to test the line speeds. I’m 7.5 miles from my CO, so my connections to my old ISP are either 31.2K or 28.8K. However, I always get a 28.8K connection to all the new ISP’s I’ve tried (about 12 different numbers). I’ve done line noise tests and based on the results I think I should be getting a faster connection. Here are the nitty-gritty details from a typical test connection:

=======================
ati6
U.S. Robotics 56K FAX INT Link Diagnostics...

Chars sent 0 Chars Received 741
Chars lost 0
Octets sent 0 Octets Received 339
Blocks sent 0 Blocks Received 22
Blocks resent 0

Retrains Requested 1 Retrains Granted 0
Line Reversals 0 Blers 0
Link Timeouts 0 Link Naks 0

Data Compression V42BIS 0/0
Equalization Long
Fallback Enabled
Protocol LAPM
Speed 28800/26400
Last Call 00:00:26

Disconnect Reason is DISC Received

OK
ati11
U.S. Robotics 56K FAX INT Link Diagnostics...

Modulation V.34
Carrier Freq (Hz) 1829/1920
Symbol Rate 3200/3200
Trellis Code 64S-4D/64S-4D
Nonlinear Encoding ON/ON
Precoding OFF/ON
Shaping OFF/ON
Preemphasis (-dB) 6/2
Recv/Xmit Level (-dBm) 15/11
Near Echo Loss (dB) 23
Far Echo Loss (dB) 52
Carrier Offset (Hz) 2520
Round Trip Delay (msec) 10
Timing Offset (ppm) 3584
SNR (dB) 37
Speed Shifts Up/Down/Null 0/0/0
Status :

OK
aty11

3300 17

3750 36
OK

Here’s the modem log from the connection:
=======================
03-25-2002 23:12:38.90 - U.S. Robotics V92 Fax PCI in use.
03-25-2002 23:12:38.92 - Modem type: U.S. Robotics V92 Fax PCI
03-25-2002 23:12:38.92 - Modem inf path: USROBO~1.INF
03-25-2002 23:12:38.92 - Modem inf section: Modem_00D3PnP
03-25-2002 23:12:39.19 - 115200,N,8,1
03-25-2002 23:12:39.19 - 115200,N,8,1
03-25-2002 23:12:39.19 - Initializing modem.
03-25-2002 23:12:39.19 - Send: AT<cr>
03-25-2002 23:12:39.19 - Recv: AT<cr>
03-25-2002 23:12:39.19 - Recv: <cr><lf>OK<cr><lf>
03-25-2002 23:12:39.19 - Interpreted response: Ok
03-25-2002 23:12:39.19 - Send: AT&F1E0Q0V1&C1&D2S0=0<cr>
03-25-2002 23:12:39.20 - Recv: AT&F1E0Q0V1&C1&D2S0=0<cr>
03-25-2002 23:12:39.20 - Recv: <cr><lf>OK<cr><lf>
03-25-2002 23:12:39.20 - Interpreted response: Ok
03-25-2002 23:12:39.20 - Send: ATS6=8<cr>
03-25-2002 23:12:39.20 - Recv: <cr><lf>OK<cr><lf>
03-25-2002 23:12:39.20 - Interpreted response: Ok
03-25-2002 23:12:39.20 - Send: ATS7=60S19=0L0M1&M4&K1&H1&R2&I0B0X4<cr>
03-25-2002 23:12:39.21 - Recv: <cr><lf>OK<cr><lf>
03-25-2002 23:12:39.21 - Interpreted response: Ok
03-25-2002 23:12:39.21 - Dialing.
03-25-2002 23:12:39.21 - Send: ATDT;<cr>
03-25-2002 23:12:40.50 - Recv: <cr><lf>OK<cr><lf>
03-25-2002 23:12:40.50 - Interpreted response: Ok
03-25-2002 23:12:40.50 - Dialing.
03-25-2002 23:12:40.50 - Send: ATDT#######<cr>
03-25-2002 23:13:17.56 - Recv: <cr><lf>CONNECT 28800/ARQ/V34/LAPM/V42BIS<cr><lf>
03-25-2002 23:13:17.56 - Interpreted response: Connect
03-25-2002 23:13:17.56 - Connection established at 28800bps.
03-25-2002 23:13:17.56 - Error-control on.
03-25-2002 23:13:17.56 - Data compression on.
03-25-2002 23:13:17.69 - 115200,N,8,1
03-25-2002 23:13:44.08 - Remote modem hung up.
03-25-2002 23:13:44.08 - Recv: <cr><lf>NO CARRIER<cr><lf>
03-25-2002 23:13:44.08 - Interpreted response: No Carrier
03-25-2002 23:13:44.15 - Hanging up the modem.
03-25-2002 23:13:44.15 - Send: ATH<cr>
03-25-2002 23:13:44.15 - Recv: <cr><lf>OK<cr><lf>
03-25-2002 23:13:44.15 - Interpreted response: Ok
03-25-2002 23:13:44.15 - 115200,N,8,1
03-25-2002 23:13:44.15 - Send: AT#UD<cr>
03-25-2002 23:13:47.15 - Recv: <no response>
03-25-2002 23:13:47.15 - WARNING: Unrecognized response. Retrying...
03-25-2002 23:13:47.15 - Send: AT#UD<cr>
03-25-2002 23:13:47.30 - Recv: <cr><lf>DIAG <2A4D3263 00=10><cr><lf><cr><lf>D
03-25-2002 23:13:47.30 - WARNING: Unrecognized response. Retrying...
03-25-2002 23:13:47.30 - Send: AT#UD<cr>
03-25-2002 23:13:47.32 - Recv: 7 15=34><cr><lf><cr><lf>DIAG <2A4D3263 16=00 1
03-25-2002 23:13:47.32 - WARNING: Unrecognized response. Retrying...
03-25-2002 23:13:47.32 - Send: AT#UD<cr>
03-25-2002 23:13:47.35 - Recv: G <2A4D3263 34=6720 35=7080><cr><lf><cr><lf>DI
03-25-2002 23:13:47.35 - WARNING: Unrecognized response. Retrying...
03-25-2002 23:13:47.35 - Send: AT#UD<cr>
03-25-2002 23:13:48.36 - Recv: 00 57=00000016><cr><lf><cr><lf>DIAG <2A4D3263
03-25-2002 23:13:48.36 - ERROR: Unable to recover from unrecognized response.
03-25-2002 23:13:48.36 - Session Statistics:
03-25-2002 23:13:48.36 - Reads : 1750 bytes
03-25-2002 23:13:48.36 - Writes: 120 bytes
03-25-2002 23:13:48.36 - U.S. Robotics V92 Fax PCI closed.
=============================

With an SNR of 37 and an A/D-D/A value of 19 (36-17), I don’t see why my connection is always 28.8K. I know my computer and modem (USR 56K Performance Pro – 3CP5610A) are working fine because when I took my PC to work (1/2-mile from the CO) I was able to get 46K connections every time. I am using the latest drivers for my modem. Is there something else shown in these settings that could explain why my connections are so slow?

If anyone has any advice on things I can try to speed up the connection, I’d love to hear about it. The difference from 28.8K to 31.2K isn’t much, but when your speeds are that slow, every little bit helps.

Thanks, Mark

PS: This is a great site. I've learned a tremendous amount in the past week!

charles
Tl Posts:
5879

USA
Posted - 3/26/2002 1:45:34 AM  Show Profile  Email Poster  Edit Message
Have you had a second line installed? If you have tried your pc at another location and got a good connection than it is your phone line. Try unhooking all phones from there jacks.Are you using any type of surg device for the phone line? You could hook to the telco box out side to see if it is in the house line also.
greggae
Tl Posts:
8

USA
Posted - 3/26/2002 5:41:12 AM  Show Profile  Email Poster  Edit Message
It was my understanding that your SNR needed to be above 45 to get a v90 connection. You might want to try an RFI filter from Radio Shack. See this thread: http://forum56.com/topic.asp?whichpage=6&pagesize=15&forum_title=USR&topic_ID=2737&forum_id=7&Topic_title=USR+5610A+GARBLED+NOISE
Troubled_user
Tl Posts:
263

USA
Posted - 3/26/2002 1:20:34 PM  Show Profile  Email Poster  Edit Message

true. 37 is a marginal SNR, meaning that you would get between 29.2 V90 and 28800/31200 V34.

please attach an ATy11 and an ATi11 hyperterminal result, also

MarkN
Tl Posts:
5

USA
Posted - 3/26/2002 3:34:29 PM  Show Profile  Email Poster  Edit Message
Thanks for the replies everyone. Here's a little more info:

I only have one phone line in my house. The phone line comes in to my garage and feeds right to a jack. A short phone line jumps to another jack, and the line from there feeds throughout my house. I moved my computer to the garage and plugged it into the first jack. That disconnected all the other phone lines/equipment in my house, but I still got the same results.

I was expecting a higher speed based on some information I found at http://www.modemhelp.net A chart there shows the following:

SNR Expected "Stable" Speed
40+ 33,600 - 56,000
37-40 33,600-56,000 (a little unstable at high speeds)
34-37 31,200-33,600
31-34 28,800-31,200
29-31 26,400-28,800
28-29 24,000-26,400

With an SNR around 37, I was expecting a connection from 31,200 to 33,600. I know I won't get V.90 speeds, but I'd be happy with something in this range. I've even gotten an SNR of 46 on a few connections, but the speed is always 28.8K.

Responses to other comments:
----------------------------
I have to 3 lights with dimmers, but they were all turned off when I did the tests.

The ati11 and aty11 results are part of my original posts.

Any other thoughts/ideas, or am I stuck with 28.8K? :(

- Mark

MarkN
Tl Posts:
5

USA
Posted - 3/26/2002 3:34:43 PM  Show Profile  Email Poster  Edit Message
Bah, double post.
Edited by - MarkN on 3/26/02 3:37:20 PM
Bob Starnes
Tl Posts:
4360

USA
Posted - 3/26/2002 9:46:39 PM  Show Profile  Email Poster  Edit Message
Might try disabling V.90 and X2, use S32=98 in the Extra Settings. Then try a connection to see if you get a little better speed.

greggae
Tl Posts:
8

USA
Posted - 3/27/2002 5:49:13 AM  Show Profile  Email Poster  Edit Message
Try the filter from Radio Shack. It's only $11 and I bet they'd let you take it back if it doesn't work. I had no dimmers, overhead fans or anything obvious interferring. My SNR was the same as yours. I now get connections of 50.6 almost every time. It may not work for you, but if you read the link I provided you will see that there is clearly a problem with noise on the 5610A and B.
greggae
Tl Posts:
8

USA
Posted - 3/27/2002 5:58:47 AM  Show Profile  Email Poster  Edit Message
Also forgot, to really exclude a problem in your house wiring, you need to check at the box on the outside of your house. If it is relatively recent, there should be a jack in the box that you can plug into with a phone and listen for noise. By doing that, you connect directly with the line on the street. Your jack inside your garage is still connected to the rest of the wiring in your house and will likely give you a similar result if there is noise on the line. Unfortunately, it means you have to listen for audible noise and that is sometimes not real obvious. Just listen to the dial tone and see if you hear any static, crackling, buzzing etc. You can do that within your house also. With close attention, mine could be heard through the PC speaker when the modem was connecting. Good luck.
Troubled_user
Tl Posts:
263

USA
Posted - 3/27/2002 1:31:46 PM  Show Profile  Email Poster  Edit Message
>34-37 31,200-33,600 connects

It is VERY rare to get a V34 connection above 28800. My modems could all hang on to 50-52 with no problem, but they only connect at 28800 in V34 mode. My SNR is 57

MarkN
Tl Posts:
5

USA
Posted - 3/27/2002 11:04:14 PM  Show Profile  Email Poster  Edit Message
Thanks again for the replies.

Bob: I used the S32=98 init string and tried several test calls, but it had no affect. I'm somewhat new to modem problems, so forgive me for asking but how could this have helped? I always get V.34 already. Is this one of those secrets that sometimes allows a modem to get better V.34 connections?

gregae: I'm going to buy an RF phone line filter tomorrow and see if it has any affect. The tests I did from my garage were. The phone line comes out of the ground, through the garage wall, and into the back of a phone jack -- no splits at this point. A short phone cable jumps from the front of that jack to the front of another. Out the back of that one is the lines that run throughout the house. By plugging my computer into the first jack, all the equipment in my house was disconnected and my PC was the only thing plugged in.

Troubled_user: I didn't realize V.34 connections were limited to 33.6K and that those speeds were rarely achieved. I guess I should be thankful that I got 31.2K for a while.

Thanks again to everyone -- I've learned a lot from all the information. If anyone has any more tips, please post them.

- Mark

charles
Tl Posts:
5879

USA
Posted - 3/28/2002 12:31:54 AM  Show Profile  Email Poster  Edit Message
You might get a modem that support K56 and a ISP that supports it.It is a downgrade from V90 but better than V34.
greggae
Tl Posts:
8

USA
Posted - 3/28/2002 5:56:30 AM  Show Profile  Email Poster  Edit Message
Good luck Mark. The place in your garage may be the right box afterall. Do you have a box outside? If you don't, then this indeed may be the phone company's box. If you disconnect the jack there and all your internal stuff is disconnected, you have probably tested it in an OK place.
That filter may not do the trick, but for me at least it was a $10 gamble that was worth it. I has spent countless hours trying to get that SNR higher. Let me know how it comes out.
charles
Tl Posts:
5879

USA
Posted - 3/28/2002 7:31:34 AM  Show Profile  Email Poster  Edit Message
http://modemsite.com/56k/x2-adconversion.asp


http://www.frostbyte.com.au/public/support/linequality.html

charles
Tl Posts:
5879

USA
Posted - 3/28/2002 7:56:17 AM  Show Profile  Email Poster  Edit Message
Examine the values of 3300 and 3750 from the Y11 screen. These values indicate the
degree of “rolloff” in signal power at the high end of the frequency spectrum.
Subtract the value for 3300 and from the value of 3750. If the difference is equal to or
greater than 25, that is very good evidence of an additional analog-to-digital conversion
If the value is betwen 20 and 25, you MAY have too many A/D, D/A conversions and you may not be able to achieve 56k speeds.
signal-to-noise ratio (SNR)

A measure of link performance arrived at by dividing signal power by noise power.
Typically measured in decibels. The higher the ratio, the clearer the connection.
Edited by - charles on 3/28/02 9:25:37 AM

timoch
Tl Posts:
16

Posted - 3/28/2002 10:11:46 AM  Show Profile  Email Poster  Edit Message
I have the choice of dialup numbers, one in my town and another a few miles away. The local number gives a SNR of 46 and connects at 45333, and the other gives a SNR of 37 and usually connects at 31200. On the occasions when the latter connects higher, the SNR is up to 42, but the connection becomes unstable and often retrains. I've found that the Radio shack filter doesn't help the SNR, only RF noise. I live in a fairly new house, but did help the SNR marginally by disconnecting all of the wire connections in the phone lines, burnishing them, applying anti oxidant compound, and reinstalling. In the process, I did find a couple of loose connections which may have had some resistance.
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