lawrenc@nvanbc.UUCP (Lawrence Harris) (01/06/88)
We are currently using Gandalf SAM224 modems on our decserver 200's to
provide both dial in and dial out services. However there are lots of
problems getting the baud rate to change correctly when you connect to
a 1200 baud only site. We can get the modems to work at 1200 or 2400
but not both when used for dial out, dial in seems not to be a problem.
Could the readers send me info on what modems they are using on the
DECSERVER 200's and how well they work. I will summarize any replys
and let the readers of this group know the results.
Thanks in advance, Lawrence.
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UUCP: {ihpn4!alberta,uw-beaver}!ubc-vision!van-bc!nvanbc!lawrence
SNAIL: 733 Sylvan Ave., North Vancouver, B.C., Canada, V7R 2E8
PHONE: 1-604-736-9241 (09:00-17:00 PST) 1-604-420-9518 (after 17:00 PST)gil@icus.UUCP (Gil Kloepfer Jr.) (01/09/88)
In article <513@nvanbc.UUCP> lawrenc@nvanbc.UUCP (Lawrence Harris) writes: > >We are currently using Gandalf SAM224 modems on our decserver 200's to >provide both dial in and dial out services. However there are lots of >problems getting the baud rate to change correctly when you connect to >a 1200 baud only site. We can get the modems to work at 1200 or 2400 >but not both when used for dial out, dial in seems not to be a problem. > > [....] > >Thanks in advance, Lawrence. Lawrence, I hate to break the bad news to you but I posted this problem on the net a while back...we all (to my knowlege) came to the conclusion that it could not be done. To those out in net-land who wish to give it their best shot, here are the things that don't work: 1. Dynamic mode with SET TERMINAL/SPEED 2. Split-speed mode 3. Setting the port Autobaud In short, I could only get the port to work at one speed, and that was the one that it was defined for when configuring the port. At Bowne, we use the Maxum Super-modem 2400, which is a Hayes-compatible. However, I tried setting-up the port using a VT220 as a "modem" with NO results. If anyone has any ideas that they have tryed and work, please post them to the net, as well as sending them to Lawrence. I think many would benefit from the info. A quick summary of the problem since some will misunderstand -- we all know that a DECserver-200 will change speeds automatically when someone dials into it and the port is set to autobaud. Our problem is when you want to use the modem to dial-out, and need to use the modem at 300, 1200, and 2400 baud at different times. Yeah, if you're priv'ed on a server port, you can set this manually. However, I think what we're looking for is a means of doing this from the host alone without fooling with the server. +====================================+========================================+ | Gil Kloepfer, Jr. | Net-Address: | | Senior Programmer | {boulder,ihnp4,talcott}!icus!gil | | Bowne Management Systems, Inc. | Voice: Home: (516) 968-6860 | | 235 E. Jericho Turnpike | Office: (516) 248-6840 x796 | | Mineola, New York 11501 | Internet: gil@icus.UUCP | +====================================+========================================+ | Disclaimer: My employers know I'm right, but will never admit to it... | +=============================================================================+
rrk@byuvax.bitnet (01/11/88)
We use Multitech. It took a while to get all the setup correct, but it
works fine all speeds both dorections automatically ajusting.
Ray Whitmer
AMMON::RAYrrk@byuvax.bitnet (01/13/88)
Sometimes I get the feeling that noone is listening...or reading their manuals.
I have stated several times that we are working multiple speeds automatically
on dialout from a DEC Server. If people would read their DECServer manuals,
they would first of all discover, that at least according to DEC, it IS
impossible to support three or more (e.g. 300, 1200, and 2400) dialout speeds
from a DEC Server 200, but it is very easy to get two to work. Right now,
all we do is allocate a reverse LAT port and go into kermit. Then we dial
out. The server will automatically switch between 2400 (set as the primary
outgoing speed) and 1200 (the secondary outgoing speed) without the user
knowing anything, except that the modem sends back a connect message telling
the speed at which connection was accomplished. Read the orange three-ring
DECServer 200 documentation carefully, and follow the instructions. It
was so long ago that we set them up, that I don't remember all the steps,
that's what my manual is for. These modems serve simultaneously as outgoing
and incoming modems, automatically switched by allocating the reverse LAT
or incoming calls (which seem to have full multispeed AUTOBAUD, but I wouldn't
swear it, since our modems don't bother with 300 baud, and from which up
to 8 sessions can be initiated). Did I leave any holes, so that you still
think my modems don't work from my DECServer 200? If you have any specifics
you would like to ask about, such as DECServer port characteristics, after
you set it up BY THE BOOK, I would be more than happy to send them to you,
although I can tell you before hand, that it was done BY THE BOOK. Try
it.
Ray Whitmer
AMMON::RAYADCDRW%SPEEDY@UNCG.BITNET ("Don Wright, AdCC, x5835") (01/13/88)
> > > >We are currently using Gandalf SAM224 modems on our decserver 200's to > >provide both dial in and dial out services. However there are lots of > >problems getting the baud rate to change correctly when you connect to > >a 1200 baud only site. We can get the modems to work at 1200 or 2400 > >but not both when used for dial out, dial in seems not to be a problem. > > > > [....] > > > >Thanks in advance, Lawrence. > >Lawrence, > >I hate to break the bad news to you but I posted this problem on the net >a while back...we all (to my knowlege) came to the conclusion that it could >not be done. > [...] > Well, I do know if *one* way.... What I've done is to use a modem which can do speed conversion (FOUL!). I'm using the Multi-Tech 224 EH modems which have MNP error correction. As an added bonus with the error correction option, you get the ability to configure the modem's serial port speed to function independently of the modem's actual communications speed. In other words, you can have the modem taking to the other modem at 1200 while the modem talks 2400 to your decserver. So then all you gotta do is set up your decserver port to autobaud DISABLED and set the speed to match the serial port speed on the MODEM and let the modem handle the differences in speed both dialin and dialout. At our site, when you dial in, the modem first wakes up at 2400, drop to 1200, 300, and finally 110 (gag) until it matches the originating modem. Due to the speed conversion inside the modem, the decserver port always sees 2400. On dialout, the decserver port and the serial port on the modem still remain at 2400 and the communications speed of the modem matches whatever it hooks to -- again the modem speed conversion doing all the work. I don't have any experience with other modems with this feature; maybe other MNP modems work similarly (?). Hope this has helped. Don Wright VAX Systems Manager Administrative Computer Center University of NC at Greensboro WRIGHTD@UNCG.BITNET
gil@icus.UUCP (Gil Kloepfer Jr.) (01/16/88)
In article <57rrk@byuvax.bitnet> rrk@byuvax.bitnet writes: >Sometimes I get the feeling that noone is listening...or reading their manuals. >I have stated several times that we are working multiple speeds automatically >on dialout from a DEC Server. If people would read their DECServer manuals, >they would first of all discover, that at least according to DEC, it IS >impossible to support three or more (e.g. 300, 1200, and 2400) dialout speeds >from a DEC Server 200, but it is very easy to get two to work. Uh huh. Simple as pie. I did read that three-ring binder and they tell you how to connect to everything under the sun except a multi-speed voice-grade modem. They SAY that the alternate speed stuff is correct...but... (read-on) >Right now, >all we do is allocate a reverse LAT port and go into kermit. Then we dial >out. The server will automatically switch between 2400 (set as the primary >outgoing speed) and 1200 (the secondary outgoing speed) without the user >knowing anything, except that the modem sends back a connect message telling >the speed at which connection was accomplished. Magic...I say.. Absolute magic. Now, can you tell me how the MODEM knows what this speed is? Unless I am gravely mistaken, you have to establish a speed that you wish to use on the modem BEFORE you dial-out. At least this is so on a Hayes-compat. modem. This is what most of us are using to dial-out I think. Unless you have a modem that does speed conversion for you, or you use a special line on the RS232 port which handles speed (no, I didn't look further into this because it wasn't satisfactory this way), there is NO WAY for the SERVER to know what speed you wish to communicate with the remote system at. Unless it is magical, of course. >Read the orange three-ring >DECServer 200 documentation carefully, and follow the instructions. It >was so long ago that we set them up, that I don't remember all the steps, >that's what my manual is for. These modems serve simultaneously as outgoing >and incoming modems, automatically switched by allocating the reverse LAT >or incoming calls (which seem to have full multispeed AUTOBAUD, but I wouldn't >swear it, since our modems don't bother with 300 baud, and from which up >to 8 sessions can be initiated). Did I leave any holes, so that you still >think my modems don't work from my DECServer 200? If you have any specifics >you would like to ask about, such as DECServer port characteristics, after >you set it up BY THE BOOK, I would be more than happy to send them to you, >although I can tell you before hand, that it was done BY THE BOOK. Try >it. > > Ray Whitmer > AMMON::RAY Ray, most of us are not total idiots and don't need to be spoken to in such a pathetic manner. First off, I have set my DECserver BY the God Damn BOOK. I took several hours with the assinine book, trying to find what I was looking for. I was able to get something working, but it didn't resemble anything like "multiple" (2) speeds. When I got something intelligent from the port, the only way I could dynamically switch speeds was by being privileged on the server and setting the speeds by hand. This is unsatisfactory. The ONLY way I can see that you can be using this method is by the RS232 speed control line (no flames if this is an invalid assumption, I don't have THE BOOK, THE DECSERVER or THE COMPUTER in front of me, I just got back from vacation and am AT HOME). With Hayes-compatibles, and most other smart modems, the speed is determined by a particular sequence of characters being transmitted at a certain speed before a connection is established. This being the case, there has to be a way of setting the port speed, as in SET TERMINAL/SPEED=xxx LTAy:, **BEFORE** a connection is made. This is what "The Book" doesn't seem to address. They are more concerned with dedicated modems conecting remote systems, and downgrading speed when telephone line noise is bad. There is another book called the VMS 4.6 release notes. This book says, in not so many words, that the SET TERMINAL/SPEED=xxx for a LAT device doesn't work. They give some examples of what DOES work. (anyone out there have them and care to quote?). PS: Yes, we DO listen. I posted an article months ago, when I was working on this. Nobody had any concrete solutions. I tried and was unsuccessful, and so I scrapped the idea, in the interest of wasted time. +====================================+========================================+ | Gil Kloepfer, Jr. | Net-Address: | | Senior Programmer | {boulder,ihnp4,talcott}!icus!gil | | Bowne Management Systems, Inc. | Voice: Home: (516) 968-6860 | | 235 E. Jericho Turnpike | Office: (516) 248-6840 x796 | | Mineola, New York 11501 | Internet: gil@icus.UUCP | +====================================+========================================+ | Disclaimer: My employers know I'm right, but will never admit to it... | +=============================================================================+
grenfell@dalcsug.UUCP (Phil Grenfell) (01/18/88)
I have done alot of work on TANDEM computers that do *not* allow you to
change the baud rate of the serial ports without shutting down the
entire computer and running a SYSGEN program that takes about an hour.
Our solution to these autobaud problems was to buy Paradyne modems. Paradyne
has a line of Hayes compatable modems that allow you to fix the
host-modem baud rate independantly of the modem-(remote modem) baud rate.
For example you could set your hosts serial port to 9600b and not worry
about what speed people dial into you at or what speed you connect at when
dialing out. These are the only modems I know of that do this and it is
a really super feature.
Note: I am not related to Paradyne Corp. in any way. I'm just a satisfied
customer.rrk@byuvax.bitnet (01/20/88)
I didn't mean to offend anyone by my posting. I posted essentially the
same information that I posted now three times previously and no one
acknowledged that the questions had either been properly or improperly
addressed. I can see that my response was out of line, but the fact remains
that the DECServer 200 communicates properly and automatically at both dial
in and out speeds.
With 1 DECServer devoted to nothing but modems (in an isolated room), it would
be very difficult to manually switch speeds on the DECServer, fortunately,
the DECServer appears to do this on outgoing calls as well as incoming when
the fallback speed is correctly set. I don't have the book in front of
me right now either, but I believe that after the modem begins communication
at the proper speed, the port also decides to communicate at either the
primary speed or the fallback speed (probably using a process similar to
autobaud). We have nothing but RS232 cables between the DECServer and the
modems.
I was insistent about the book, because it (according to my best recollection)
explicitly mentions use of the fallback speed in connection with multispeed
modems, dialouts, I believe. The book, definately (again, my best
recollection) does NOT say how to do a SET TERM/SPEED=xxx. I dial out
frequently to 1200 and 2400 baud systems. The only time I have to go in
the computer room is when too many modems get hung (about once every two
weeks). Why do a SET TERM/SPEED=nnn when the port/modem can switch by itself?
I will look it up in the book and post the page number.
Ray Whitmer
AMMON::RAYJOE@FHCRCVAX.BITNET (Joe Meadows) (01/20/88)
I'd like to respond to an earlier discussion about multiple speed
incoming/outgoing modem use on a DEC Server 200.
The manual does clearly state thet it can support TWO speeds, a
primary speed and a secondary speed. I assumed this was true for incoming
calls only, however, I was wrong. I have a Hayes 2400 baud modem set up
with a primary speed of 2400, and secondary speed of 1200. Incoming calls
switch correctly (note that you need pin 12 (or 23 I think, but 12 is the
more correct one) wired up for the modem to be able to tell the server
wether it is running in high or low speed. Much to my surprise my outgoing
calls also were switching to 1200 when I called slow machines. Actually,
to be honest, I haven't called out to a machine that has a 2400 baud modem,
so I could actually have screwed something up, but I doubt it very much,
since (a) my primary speed is 2400, hence I do an AT command at 2400 baud
(from server to modem), the modem switches to 1200 baud (and lowers the
signal on pin 12, indicating low speed) and so the server (noticing the
pin 12 state change) starts sending and receiving at 1200.
Since only one pin designates low or high speed, the modem
can only switch between two speeds. To support more than two speeds
you would need a smarter modem, someone suggested a paradigm, I believe
a Telebit trailblazer would also do the trick.
Cheers,
Joe Meadows Joe@fhcrcvax.bitnet