From news.csc.fi!news.funet.fi!news.kolumbus.fi!news.sprintlink.net!aimnet.com!news2.aimnet.com!usenet Wed Dec 6 13:12:34 1995
Path: news.csc.fi!news.funet.fi!news.kolumbus.fi!news.sprintlink.net!aimnet.com!news2.aimnet.com!usenet
From: JNavas@NavasGrp.com (John Navas)
Newsgroups: comp.dcom.modems
Subject: The Navas 28800 Modem FAQ -- 3/5
Date: Sat, 25 Nov 1995 21:37:01 GMT
Organization: The Navas Group, Dublin, CA, USA
Lines: 692
Message-ID: <49823s$754@news2.aimnet.com>
References: <483f6b$lkt@news2.aimnet.com>
NNTP-Posting-Host: dial-bp1-8.iway.aimnet.com
X-Newsreader: Forte Free Agent 1.0.82
<<cont>>
What are the best (data/fax) comm programs for Windows?
There are several excellent programs, and what is best for one
won't necessarily be best for others.
For data comm, the personal favorites of the author are
HyperACCESS for Windows (commercial from Hilgraeve[200]) and the
near-clone WinComm PRO (commercial from Delrina[201]). Both are
extremely powerful while being very easy to use. For those on a
budget, there is a freeware version of WinComm called WinComm
Lite[202]. (There is also a freeware DOS comm program from Delrina
called FreeComm[203]. Neither WinComm Lite nor FreeComm has been
reviewed by the author.)
Popular shareware alternatives include:
Softerm Plus[204] (X/Y/ZMODEM with SLIP and TCP/IP)
Telix for Windows[205]
UniCom[206]
WinQVT[207] (VT-220 emulator with X/Y/ZMODEM/Kermit)
WinRamp Lite[208] (w/RIP)
For fax comm, the personal favorite of the author is WinFax PRO
(commercial from Delrina[209]). It integrates well with WinComm
PRO, and the two can be purchased in a discounted bundle as the
Delrina Comm Suite. (If you experience fax problems with a USR
modem, see "Any other USRobotics tips?[210]")
FLASH (7/8/95): Delrina[211] is to be acquired by
Symantec[212].
The author does not recommend Procomm Plus for Windows
(commercial from Datastorm). While version 1.xx evolved into a
robust (albeit quirky) data comm program, version 2.xx has
suffered from "featuritis" and has been plagued with many problems
(e.g., greatly excessive locking of memory below 1 Mb [See "PRB:
Avoiding 'Insufficient Memory to Run' Errors[213]"]).
Button[214] [Return to top[215]]
___________________________________
Why do I sometimes have problems connecting?
See below and also "Any other USR tips?[216]".
Why do I sometimes get abruptly disconnected?
Disconnections may be caused by momentary drops of DTR by
certain comm applications. (By default most modems respond to a
drop of DTR by hanging up.)
With most modems you can work around this problem by disabling
DTR (i.e., &D0). Note that when DTR is disabled you have to
escape the modem to command mode and use the "ATH" command to
hang up.
With USR modems you can also use register S25 to work around
the problem (e.g., S25=10 will ignore a DTR drop of less than
10/100 or 1/10 second, which is twice the default of 5/100
second).
For those experiencing disconnects (and/or erratic connection
speeds) when calling Rockwell-based V.FC modems from a USR
28800 (V.FC or V.34) modem, a firmware fix is now available for
the Sportster (dated 4/18/95 or later for USA modems) by
calling USR (708-982-5151); for the Courier, the fix (dated
7/5/95 or later for USA modems) is available by FTP[217]. In
the meantime, the author's workarounds (which may help in some
cases even if you have the updated firmware) are:
Disable V.42 Detect Phase (i.e., S27=48).
-- or --
Disable V.42 completely (i.e., S27=32). If you then sometimes
get non-error-correcting connections, force error-correction
mode (i.e., &M5). You may find that you have to redial several
times to get connected; if so, try the following.
-- and/or ---
Disable the highest symbol rates (e.g., S54.5=1S54.4=1S54.3=1).
This will limit your top speed (to 24000 in this example),
depending on how many symbol rates you disable (3429, 3200, and
3000 in this example).
-- also --
With V.FC-only firmware (as opposed to the newer V.34 firmware)
it may help to also disable the 32S-2D map (i.e., S55.2=1).
-- finally --
It may also help to set S10=255.
With a USR 28800 modem, you can determine the technical reason
for a disconnect by issuing the ATI6 command immediately after the
disconnection.
If possible, set these options on a phone number-specific basis.
With comm apps which lack that capability, you may be able to
embed them in the phone number; e.g., "^H^HS27=48DT555-1212". (The
two "^H" backspace characters erase the "DT" in an "ATDT" dial
command so that the "S27=48" will be accepted, and then the
following "DT" replaces the "DT" that was erased; i.e., "ATDT" +
"^H^HS27=48DT555-1212" = "ATS27=48DT555-1212".)
Button[218] [Return to top[219]]
___________________________________
Why do connections sometimes seem to run slower and slower?
The following is a discussion of the so-called "spiraling death"
problem that has been observed on the Sportster 28800 (and
sometimes even the Courier V.34), where the modem will fall back
over time on certain connections to ever lower speeds.
What we are really concerned with here is fall-forward, not
retraining. (See "What is 'retraining'? and What are 'fall-back'
and 'fall-forward'?[220]") Retraining is normally a rare event. So
the problem is really that the Sportster 28800 sometimes does not
fall-forward when it is able to do so. The symptom is that the
Sportster 28800 is sometimes observed to fall back to
progressively lower speeds without ever being observed to fall
forward back to higher speeds. The implication is that line
conditions would have permitted a higher speed, which may or may
not have been true. (It's impossible to say for sure without
elaborate test equipment.)
THE ATO1 CONNECT RESPONSE CONFUSION
Some of the evidence used to support the claim that the
Sportster 28800 doesn't fall forward has been that ATO1 (forced
retraining) returned the modem to a higher speed. The problem with
at least some of these reports is that people have assumed that
the CONNECT response to ATO1 reports the new speed after
retraining. It doesn't, as should be obvious if you notice that
the response appears before the retraining sound (heard with M2)
is completed. The response sometimes shows the previous connection
speed, and sometimes shows the original connection speed, but
never the new speed. The only way to correctly determine the
connect speed after retraining is to escape to command mode and
use the ATI6 command! (See Any other USRobotics tips?[221], Any
Trumpet Winsock tips?[222], and Why can't I get back on-line after
I escape to command mode?[223])
Suppose that a phone connection is such that the Sportster 28800
CONNECTs at a high speed (e.g., 28800), but then falls back to a
lower speed (e.g., 24000) due to line conditions. Escape to
command-mode followed by ATO1 might well make you think that
retraining has returned the modem to the original high speed (due
to a CONNECT 28800 response) when it may well not have.
Disconnecting and reconnecting could produce the same misleading
indications. In other words, these may just be plain old poor
connections. The moral here is that you must use ATI6, and only
ATI6, to check the current connection speed.
Another problem is that ATO1 may not change the current speed,
or may even reduce it, depending on changing line conditions. And
it's hard to keep ongoing auto fall-back/forward from confusing
the issue (unless you use M2 and listen carefully for the sound of
the speed shifts, a small beep or blip in the ongoing carrier
hiss). The only way to know for sure whether or not the speed
changed is to use ATI6 immediately before and after ATO1.
SPORTSTER PROBLEMS
Does the Sportster 28800 fall-forward automatically or not? From
extensive testing (literally hundreds of hours to both USR and
non-USR modems) the author concludes that the answer is: often
yes, but sometimes no. The author has run many tests where the
Sportster 28800 was forced back to (say) 16800, and then it
rapidly fall forward to a much higher speed. But the author has
also run some tests where it stayed at 16800. This seems to be a
function of both line conditions and the modem at the other end of
the connection.
Note that this problem is not absolute -- while some users do
encounter it on some connections, many users never encounter it.
Another possibly related problem that some have reported with
the external Sportster 28800 (not the internal Sportster, and not
either type of the Courier) is that adjusting the speaker volume
control while on-line causes the modem to fall back. Anecdotal
reports suggest that higher connection speeds may be possible if
the volume control is turned all the way down before the initial
negotiation (and left there). Turning off the speaker with M0 is
apparently not effective.
WHAT TO DO
USR now has a fix for this problem:
"Dear USRobotics Customers:
USR has received many comments about a condition identif
ied by some users as Spiraling Death Syndrome. The conditio
ns stated are that the Sportster v.34 modem degrades it's t
hroughput speed as the product heats up.
Although we have been unable to duplicate the problem on
a large scale, we have duplicated these symptoms on a very
intermittent basis. However, the current release of v.34 c
ode (dated 4/18/95) has allowed for greater variances in am
bient temperature swings in addition to greater compatibili
ty to non-USR products. As a result, for the next 30 days,
USR is offering a code upgrade and fulfillment program at n
o cost to our customers. Until June 9, 1995 customers simpl
y need to contact USR at 708-982-5151 and prompt for Techni
cal Support to validate the symptoms. Upon validation, USR'
s Customer Service Department will process the replacement
code order.
Please note that this is a limited time offer. Effective
Monday, June 12, 1995 the standard code upgrade program go
es back into effect. This program requires a $15 fee to cov
er the extraction tool, handling & shipping.
We thank our customers for continued support of USRoboti
cs products and it is our wish to maintain customer support
and loyalty."
The author urges all Sportster 28800 owners to take advantage of
this offer. Even though the original offer has expired, you may
still be able to get a free upgrade if you (politely) insist on
it. Or you can purchase the low-cost upgrade to 33600 (see "U.S.
Robotics announces 33.6 Kbps V.34 software for Sportster[224]"),
which contains all previous improvements.
While waiting for the fix, here are some workarounds to try:
If possible try a different modem to see if the problems
persist or not.
Try to improve your connection -- the Sportster 28800 may be
falling back in response to noise bursts on the line. (See "Why
don't I get 28800 bps speed on my connections?[225]")
If you have the external Sportster 28800, try turning the
volume control all the way down before the initial negotiation.
You can disable fallback on the transmit side (the receive side
is not affected) by setting the undocumented option of S15=2.
The downside is that you may get disconnected if line
conditions deteriorate enough to warrant a fall-back and/or you
may experience more retraining. (This option is documented for
the Courier V.34.)
If you have 11/30/94 or later Sportster firmware (date for USA
modems), you can lock the transmit speed (but not the receive
speed) in a range with &Nn&Un (e.g., &N14&U12 locks the
transmit speed between 28800 and 24000). With an appropriate
range, this may be more reliable than S15=2. (However, it does
not work on the Courier.)
Button[226] [Return to top[227]]
___________________________________
Does USR Adaptive Answer work with Procomm Plus for Windows?
How to get Adaptive Answer to work on USR Sportster modems with
Procomm Plus for Windows 2.xx (PW2.xx):
Adaptive Answer (called Call Selection by USR) works in Class 1
as well as Class 2.0 mode with 28.8 versions of both the USR
Courier and Sportster. PW2.xx does not support Class 2.0 (only
Class 1 and so-called Class 2), so it must be configured for Class
1 fax with USR modems.
The USR Adaptive Answer problem is that Datastorm apparently
assumed that all modems are like Rockwell clones, which can enable
Adaptive Answer while still in data mode. That doesn't work with
USR modems, which require the modem to be in fax mode to enable
Adaptive Answer.
Hopefully this problem will be fixed in a maintenance release.
In the meantime the author's workaround to this problem is to put
the USR Sportster modem into fax mode before enabling Adaptive
Answer. (Apparently this method does not work on the Courier.) On
the Setup | Fax Connection screen you will need to set:
Fax class: Class 1
Maximum transmit rate: 9600 [for reliability]
Maximum receive rate: 9600 [for reliability]
Class 1 adaptive answer command: +FCLASS=1+FAA=1 [no AT
or ^M]
Adaptive answer connect message: FAX
Now you should be able to Setup | Auto Answer | Data and Fax.
The command won't take when done online, but don't worry, just
wait for PW2.xx to time out, and then Online | Initialize Data
Modem to get everything working. Startup Host Mode, and you should
be in business. Note: If you leave Auto Answer set to Data and Fax
and put PW2.xx with HOST.WAX as an argument in your Startup group,
PW2.xx will launch and initialize correctly for Adaptive Answer
when you startup Windows.
Be sure to turn off Auto Answer before trying to make a data
call out, or the call will fail since the modem will be in fax
mode. Just Setup | Auto Answer | Off, and then Online | Initialize
Data Modem.
A little bit of a kludge, but it does work on the Sportster.
Button[228] [Return to top[229]]
___________________________________
Any other USRobotics tips?
Warning: USR has indiscriminately slapped the "Sportster" name
on so many different products that the author no longer feels it
is a reliable product guide. For example, recent "Sportster 28800"
and "Sportster 33600" modems have considerably different
S-register settings as compared to the original "Sportster 28800"
product. This invalidates a good deal of advice, including some
of the material in this FAQ.
28800 Sportsters can be inexpensively upgraded to 33600
(including Selective Reject[230], see "U.S. Robotics announces
33.6 Kbps V.34 software for Sportster[231]").
Useful modem commands:
ATI6, issued after a disconnect[232], will tell you the reason
for the disconnect.
ATI6 will tell you your current modem-to-modem connection speed
if you escape (e.g., with "+++") to command mode while online.
With split/asymmetric speeds (see What are split/asymmetric
speeds?[233]), ATI6 will report the two speeds as
receive/transmit. (See also "Why can't I get back on-line after
I escape to command mode?[234]" To display the current
connection speed when using Trumpet Winsock on a SLIP/PPP link,
see "Any Trumpet Winsock tips?[235]")
ATO will return you to on-line mode after you escape to command
mode; ATO1 will also request a retrain[236] (which may help if
line conditions have changed substantially).
ATI7 will tell you what firmware version (date) you have.
For a good description of the output of the ATI6 and ATI11
commands, see the FAQ by USR UK[237].
If you experience problems connecting to certain V.34 modems:
It may help to disable the 3429 symbol rate (S54.5=1), which
confuses certain modems (e.g., Hayes) that are not fully V.34
compliant during negotiation.
It may help to disable V.FC (S56.7=1).
If you experience problems connecting to certain V.34/V.FC
modems, or you otherwise want to connect with V.FC when the
remote modem supports both V.34 and V.FC, disable V.8
(S54.7=1), which effectively disables V.34.
If you have a particular number where you sometimes connect at
a very slow speed but get a much higher speed when you
immediately redial, find out if there is a Hayes modem at the
other end. If so, it may be possible to correct the problem by
updating the Hayes firmware.
If you experience problems connecting to certain older MNP
modems (esp. at 2400 bps), try S15=64. This option is only
documented for the Courier ("Unusual MNP-Incompatibility"),
but may work for the Sportster as well.
If you hear a strange ringing sound after dialing and before
the remote answers, that's Call Indicate. It's a good idea to
disable it (S54.6=1), because it can cause connection problems
with certain modems.
Some users have reported that resetting the modem before each
call improves the chances of a good connection. To do this, use
ATZn instead of AT&Fn. The options for ATZn are:
Z - reset and load profile Yn
Z1 - reset and load profile 0
Z2 - reset and load profile 1
Z3 - reset and load &F0 defaults
Z4 - reset and load &F1 defaults
Z5 - reset and load &F2 defaults
In other words, ATZ4 is a good alternative to AT&F1. Gen
erally the only problem is that you can't put more commands
on the same line with ATZn as you can with AT&Fn; e.g., yo
u can do AT&F1S11=55 but not ATZ4S11=55. If you have a comm
program that can issue more than one initialization string
(e.g., HyperACCESS for Windows or WinComm PRO), you can si
mply put additional commands in a second command string; e.
g., ATZ4 followed by ATS11=55.
If you experience faxing problems, in addition to the other
suggestions in this document (e.g., "What about third-party comm
drivers for Windows?[238]" and "Any other Windows tips?[239]")
you should make sure that you have firmware dated 4/18/95 or
later. (For a firmware upgrade, call USR at 708-982-5151.)
Otherwise, it might help to initialize the modem with S36=0. If
you are using Delrina WinFax, you might also try limiting your
send and receive speeds to 9600 bps by adding the following to
the [General] section of your WINFAX.INI file:
MaxTxSpeed=9600
MaxRxSpeed=9600
With the Sportster (not the Courier), watch out for which
profile you have set. If Y1 is set (which selects profile 1
rather than profile 0), and you do (say) ATS11=55&W, and then
later use ATZ to initialize your modem, you won't get the S11
setting you saved! The reason is that &W always saves to the
profile 0, while ATZ loads whatever profile Yn is set to, in
this case profile 1.
Options that are controlled by dipswitches are not saved in
NVRAM (profiles 0 and 1). If you want them to be in a known
state without worrying about the dipswitches, you should set
them in your initialization string (e.g., E1Q0V1S0=0&C1&D2 for
the default settings).
Button[240] [Return to top[241]]
___________________________________
Any other Windows 3.x tips?
An upgrade to Windows for Workgroups 3.11 or Windows 95 is
probably the best way to improve Windows communications.
To improve transmit (upload) performance and/or fax reliability
under Windows for Workgroups 3.11, put the following in the
[386Enh] section of your SYSTEM.INI file:
COMnTXFIFO=1
where n is the number of your modem COM port (e.g.,
COM2TXFIFO=1). This enables use of the 16550 Transmit FIFO.
(See "Do I need a 16550 UART? What is a UART?[242]")
Be careful not to confuse Windows (standard) 3.11 with Windows
for Workgroups 3.11 -- version numbers notwithstanding, they
are not the same. Windows (standard) 3.11 is essentially
Windows 3.1 with a few bug fixes (that do not directly affect
modem communications), whereas Windows for Workgroups 3.11 has
a considerably different internal architecture.
If you get "Insufficient Memory to Run" errors when starting
new applications when you still have sufficient Free Memory and
System Resources (as displayed by Program Manager Help |
About), one of your running applications is probably locking an
excessive amount of memory below 1 Mb. (See "PRB: Avoiding
'Insufficient Memory to Run' Errors[243]") Utilities are
available to deal with this problem:
Memfix[244] (GNU "copyleft" license)
MemPlus[245] (Shareware US$40)
MoreMem[246] (Shareware US$40)
If you experience lockups or strange behavior, try setting
MaxBPs=400 (or more) in the [386Enh] section of your SYSTEM.INI
file.
Contrary to "urban legends" it is possible to have a DOS
application temporarily take over a COM port from a Windows
application; i.e., it is possible to use a DOS program like
DSZ[247] to handle ZMODEM file transfers for a Windows comm app
with a less efficient ZMODEM implementation. The key to doing
this is to set ComxAutoAssign=0, where x is the number of your
modem COM port (e.g., Com1AutoAssign=0), in the [386Enh]
section of your SYSTEM.INI file. (Because the exact details
will vary from comm app to comm app, the rest of the exercise
is left to the reader.)
Good general resources are Microsoft's:
"Windows 3.1 and Serial Communications[248]" (also available by
FTP[249]).
"Windows 3.1 Serial Communications Q & A Part 2[250]"
The Windows Resource Kit[251] is also good, particularly the
SYSTEM.INI section, which is viewable on the Web:
Windows 3.1 Resource Kit SYSTEM.INI [386ENH] Section A-L[252]
Windows 3.1 Resource Kit SYSTEM.INI [386ENH] Section M-Z[253]
Button[254] [Return to top[255]]
___________________________________
What are "voice" modems?
UNDER CONSTRUCTION -- PLEASE BE PATIENT.
So-called voice modems fall into three categories:
Modems that can function as an answering machine or voice-mail
system.
Modems that can transmit data or voice over the same
connection. (Radish "VoiceView")
Modems that can transmit data and voice simultaneously over the
same connection. (DSVD)
Modems in the first category have been on the market for some
time. Modems in the second and third categories are just coming
onto the market -- expect a continuing stream of new product
announcements.
See "MODEMS: THE MAKE-IT-HAPPEN MACHINES FOR THE ULTIMATELY WIRED
OF THE 90'S[256]"
Button[257] [Return to top[258]]
___________________________________
What is ISDN?
UNDER CONSTRUCTION -- PLEASE BE PATIENT.
The most likely successor to V.34, ISDN provides up to 2-4 times
the speed of V.34 over a standard local telephone line by using
digital, rather than analog, signals. Years in the making, ISDN is
finally being widely deployed in the U.S. at the time of this
writing. To use ISDN you will need special, expensive equipment. A
problem is that ISDN transmissions are typically not compressed;
as a result, with compressible data the speed of a V.34 modem is
often comparable to a single ISDN channel. In the opinion of the
author, V.34 will probably be a cost-effective alternative to ISDN
for some time to come. ISDN information is available at:
Ascend[259]:
Pipeline 25[260]
Pipeline 50 ISDN[261]
Bellcore's National ISDN site[262]
Dan Kegel's ISDN Page[263]
IBM[264]:
WaveRunner[265] and WaveRunner PCMCIA[266] (see also "Mwave at
Watson[267]")
7845 ISDN NT-1 Extended[268]
ISDN*tek Home Page[269] (ISDN products)
Pacific Bell's ISDN User's Guide[270]
PSI InterRamp[271] (large ISDN ISP)
Motorola ISG[272]:
BitSURFR[273]
BitSURFR Pro[274]
Racal-Datacom BRI 2000[275]
Surf Communications[276] (ISDN access)
3Com Impact ISDN Digital Modems and Adapters[277]
Usenet comp.dcom.isdn[278]
USRobotics[279]:
Sportster ISDN 128K[280]
Courier I-modem with ISDN/V.34[281]
ZyXEL[282]:
Elite 2864[283]
Elite 2864I[284]
See "MODEMS: THE MAKE-IT-HAPPEN MACHINES FOR THE ULTIMATELY WIRED
OF THE 90'S[285]"
Button[286] [Return to top[287]]
___________________________________
What are SDSL, ADSL, and HDSL? {Updated!
UNDER CONSTRUCTION -- PLEASE BE PATIENT.
SDSL (symmetric-digital-subscriber-line), ADSL
(asymmetric-digital-subscriber-line), and HDSL (high-bit-rate,
digital subscriber line) are new telco technologies that have the
potential to blow ISDN[288] away. See:
ADSL Forum[289]
"AT&T modem handles TV, 6 Mbit Internet access on copper
wire[290]"
"AT&T Paradyne unveils powerful multimedia 'modern modem'[291]"
"AT&T Paradyne VideoSpan can put video onto copper
networks[292]"
Button[293] [Return to top[294]]
___________________________________
<<cont>>
