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Conference 7.286::vtstar_bugs

Title:VTstar defect reporting system
Notice:Welcome to ONTIME
Moderator:HANNAH::ALFRED
Created:Sat Dec 04 1993
Last Modified:Tue May 20 1997
Last Successful Update:Fri Jun 06 1997
Number of topics:527
Total number of notes:2496

526.0. "Buffering/Bursting Problem?" by 2251::DADDIECO (That's Just The Way It Is .....) Fri Mar 14 1997 13:33

    Question:
    
    I'm experiencing some - what appears to be  - "buffering" / "bursting"
    problems - ie when I read a long docuement via Mail for example - it
    paints the screen with the first page or two and then just hangs -
    won't finish the doc. like it's too much data or something.
    
    Any ideas on how I can remedy this?
    
    Thanx ... d.
T.RTitleUserPersonal
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526.1CFSCTC::SMITHTom Smith MRO1-3/D12 dtn 297-4751Sat Mar 15 1997 15:3110
    Sounds like a flow control problem. What settings are you using for:
    
    a) Your TCP/IP package's port speed and flow control type, PPP/SLIP
       compression, and MRU/MTU
    b) Your modem's typical connect speed, error correction, and compression,
       and its DTE speed, flow control type, and speed buffering (if settable)
    c) Your PPP/SLIP server's flow control type, compression type, MRU/MTU,
       and character escaping (e.g., set port ppp lcp map xxxx on a DECserver).
    
    -Tom
526.2SettingsGROOVE::DADDIECOThat's Just The Way It Is .....Mon Mar 17 1997 13:0722
    re: -1
    
    Your TCP/IP package's port speed and flow control type, PPP/SLIP
           compression, and MRU/MTU
    ..... not sure what to do here and where to do it .. please clarify?
    
    Your modem's typical connect speed, error correction, and compression,
           and its DTE speed, flow control type, and speed buffering (if
    settable)
    ..... connect speed set at 115200 - error correction set to ""use error
    control - compress data" --- DTE speed = can't find it? - speed
    buffering = "use FIFO"
    
    Your PPP/SLIP server's flow control type, compression type, MRU/MTU,
           and character escaping (e.g., set port ppp lcp map xxxx on a
    DECserver)
    ...... Use Flow Control = Hardware (RTS/CTS)
    
    Does this help ?????
    
    
    Thanx .... d.
526.3CFSCTC::SMITHTom Smith MRO1-3/D12 dtn 297-4751Tue Mar 18 1997 00:2952
    It seems that you got your answers all from the same place, probably
    your PPP/SLIP dialer/emulator. I don't know what that is or on what
    platform, so I can't help you much with details. What you have seems to
    be right, but you need to check the other places as well.
    
    There are at least 3 places that have relevant settings that must be
    coordinated:
    
    	1) Your dialler/TCP/IP configuration. This will have three sets of
           settings:
    
    	   a) Basic port communications settings, including port speed
    	      (115200), the type of flow control used between your PC and the
    	      modem (hardware/RTS/CTS), number of data (8) and stop (1) bits,
    	      and parity setting (none). This is what your PC uses to talk
    	      to your modem. Note that in order to use a port speed of
    	      115200, you need an internal modem with a built-in UART or
    	      an external modem _and_ a serial port with a 16550A UART.
    
    	   c) Modem initialization and dialling strings (see 2)
    
    	   b) PPP/SLIP/TCP/IP options, including PPP/SLIP compression (on),
    	      MRU/MTU/MSS/RWIN (x/y/y-40/n*(y-40) : 296/296/256/1012,
    	      552/552/512/2048, etc.)
    
    	2) Your modem. Modem characteristics are set by the dialler
           using an "AT..." initialization string prior to the "ATD..." dial
    	   string. The initialization string varies according to the
    	   particular modem, but important characteristics include the DTE
    	   speed (should be the same value as the port speed above), type of
    	   flow control (set to same as above), error correction (on),
    	   compression (optionally on - OK if your port runs at 115200),
    	   and speed buffering (usually on by default). The modem also has
    	   a "connect" speed, which is the speed by which it communicates
    	   with the other modem. Don't confuse this with the DTE speed, which
    	   is the speed between your PC and your modem (and which should be
    	   4 times the maximum connect speed in a V.34 modem).
           
    	3) Your PPP/SLIP server. This will have its own speed and flow control
    	   between _its_ modem and _its_ port. If it's not set to use
    	   hardware flow control and it _is_ running at 9600 bps or better,
    	   you may have trouble with it no matter what you do. In any case,
    	   if it's using XON/XOFF flow control, XON and XOFF characters in
    	   the data stream have to be escaped. In addition, the
    	   PPP/SLIP/TCP/IP parameters at the server should be consistent
    	   with those you set in your PPP/SLIP/TCP/IP package. If your
    	   server is a DECserver, all these things are set using a series of
    	   "set port ppp ..." or "set port slip ..." commands before you
   	   issue the "c ppp" or "c slip" command. Other kinds of servers
    	   will be different.
    
    -Tom