🚀 go-pugleaf

irvine@ks.sysnet.com (Chuck Irvine) wrote:

>
>
>I'm have two modem related problems. One is that I consistently get
>slow connects with by new sportster 28.8 (V.34+). It's never any
>better than 21.6, often is 19.2, and sometimes is 16.something. Some
>say that this isn't indicative of a problem (other than bad phone
>lines), but the troublesome thing is that only a week ago I was using
>an external supraExpress 28.8 and never got a connection below 26.5,
>and sometimes connected at 28.8. 
>
>Now here's the new thing. I find that if I connect to our USR Courier
>28.8 at whatever happens the connect speed, i.e. 21.6, 19.2, or 16.x,
>then my windows based news readers fail. For example, using Free agent
>connecting to a 28.8 modem if I try to get new headers for subscribed
>news groups, Free Agent reports that the groups no longer
>exist. However, if I reconnect on a 14.4 modem, the new headers come
>across just fine. Other windows news readers behave similarly - they
>work at 14.4 and don't at 28.8. 
>
>Curiously, I am encountering no known problems with any other tcp/ip
>applications. 
>
>If anyone can help me solve this problem, well that would be
>great. Actually, at this point even hints on how to start debugging
>the problem would be very much appreciated. 
>
>Thanks,
>-- 


Chuck -

	I had similar problems with my USRobotics V.34 modem -
until i got the settings right??? mine are -
 
      ATS=0&B&N&H1&I&M4&K&C1&D2&R2&SQV1X4&A3M0

S=0	no answer incomming calls
&B0	switch to serial port rate of remote modem
&N0	negotiate highest possible connection rate
	(up and down during session)
&H1	hardware flow control (a must for 28.8)
&I0	disable XON/XOFF flow control of received data
&M4	ARQ mode ON (modem to modem error correction
	- a must for 28.8)
&K0	Data compression disabled (this made my connection
	more reliable than turning compression on - dubious 
	benefits anyway - no flames)
&C1	send CD signal on connect - drop on disconnect
&D2	must send DTR to accept commands
&R2	Hardware flow control of received data enabled
&S0	DSR always on
Q0	display result codes
X4	result code select
&A3	protocol codes are added 	
M0	silence 

	I have played with these too much and don't want to
touch them any more. When I started ARQ wasn't on and believe
it or not sometimes it worked at 28.8 (mostly a bit lower 26.4 
I think)  - but it was terribly unreliable - bad connects - broken
connects - just hang - timeouts!!!

	Switched on ARQ - much better - but still some problems
- bad connects etc... Can't remember when I turned on Hardware
flow control - a definite improvement. but still unreliable - so
started dropping features - drop data compression (ouch!) -
drop XON/XOFF - drop anything else you can think off - you
want reliability!   Even tried to drop the &N0 negotiation during 
session but could never force a fixed baud rate at &B1&N14
(28.8) highest I could force was 14.4 &N8 (half speed - but
reliable).

	What I was trying to do was stop the modems thrashing
each other with error blocks, NAKS, compression, re-negotiate
baud rate etc.. because I was pushing for 28.8. Line stats can
be looked at with ATI6 - watch 'blocks resent!', blers (block errs?)
and NAKs - you will also get the true line speed.   Its no good
getting a higher connection speed if you use up all your bandwidth
resending blocks of data - and a good chance one end will timeout
or get confused.

	Anyway I came-up with the above settings. One thing I
did notice was that if your ISP was very busy (but you still got a 
modem connection at 20 something)  and went online with Agent
- Agent would send a packet (I don't know what - I turned on comm
trace in my Trumpet Winsock) and then about 4-5 secs later it would
re-send the packet, and so-on every 4-5 secs - the busy ISP machine
would get swamped with no hope of keeping-up with the requests.
Having swamped the ISP (even though retry time set at 60secs) Agent
would always timeout the connection.

	When this happened I would switch to &B1&N8 force 14.4
no negotiation. And mostly the ISP machine could keep-up and I'd
get a good connection.

	Doesn't sound very satisfactory and I've gone on longer
than I intended.

	alan.fay@pop3.hiway.co.uk