-











                             RECOMMENDATIONS REPORT

                                   (Revised)

                                 



                                      for







                          File Transfer Via PC Pursuit





                                 (Jan 03, 1989)



























































                       Telenet Communication Corporation

                        Field Operations HQ Tech Support

                                Reston, Virginia











































                                    CONTENTS

                                    --------









                                                                 PAGE

                                                                 ----



     1.0  Introduction...........................................  1





     2.0  Recommendations........................................  2





     3.0  File Transfer Procedures...............................  5





     4.0  Summary................................................  6





     5.0  Troubleshooting........................................  7

























































































                            SECTION 1.: Introduction

                            ------- -   ------------







     Because  of many customer complaints concerning PC Pursuit's inability

     to allow file transfers, Field Operations  was  requested  to  provide

     recommendations  for  file transfer via PC Pursuit. In compliance with

     this request, this document provides the following:



     *  Recommendation on the best file transfer protocols to be used

        with PC Pursuit.



     *  Recommendation on the hunt-confirm sequence and line parameters

        which provide optimum performance of various protocols.



     *  The average transfer rates which can be expected using the

        correct hunt-confirm sequence and optional parameter settings.



















































































                                      - 1 -                                













                          SECTION 2.: Recommendations

                          ------- -   ---------------







     This section outlines the most common  file  transfer  protocols  used

     with  PC  Pursuit. The performance of the protocols in the direct con-

     nect and PC Pursuit environments are also indicated.



     The following protocols were tested via the  Chicago  in-dial  to  the

     Washington DC out-dial; the observations are summarized below.





     XMODEM



     PC Pursuit XMODEM file transfers performed at an average throughput of

     34%  when  the  correct  hunt-confirm  and terminal type was utilized.

     XMODEM does not support flow control, therefore it is  suggested  that

     the  "relaxed"  mode  be invoked if the user's communications software

     permits this feature.





     YMODEM



     The performance of YMODEM file transfers VIA PC Pursuit was  found  to

     have  an  average  throughput of 77% when the correct hunt confirm and

     terminal type is employed.  Although  YMODEM  does  not  support  flow

     control, it uses large 1024 byte packets which the network PAD handles

     quite  readily  under  normal conditions. As a result, YMODEM is rated

     one of the faster protocols for file transfer via PC Pursuit.





     WXMODEM



     WXMODEM file transfers utilizing the correct hunt-confirm and terminal

     type performed well  with  an  average  transfer  rate  of  82%.  This

     protocol  is  capable  of  handling  flow  control which enables it to

     perform with better reliability in the PC Pursuit  environment.  Users

     should  be  aware  that an early version of PROCOMM is known to have a

     software problem which can affect  the  performance  of  WXMODEM  file

     transfers.





     KERMIT



     An  optimum  average  throughput  of  65%  was obtained by KERMIT file

     transfers via PC Pursuit. The throughput was obtained  with  a  packet

     size of 90 and a window size of 31. KERMIT software which supports the

     sliding  window  feature  performs  with  optimum efficiency in the PC

     Pursuit environment.



















                                      - 2 -                                















     SEALINK



     SEALINK file transfers via PC  Pursuit  performed  exceptionally  well

     with  an  average  throughput of 91% with the correct hunt-confirm and

     terminal type. SEALINK supports  flow  control  and  was  specifically

     designed  to  operate  in the networking environment. Some versions of

     SEALINK however, do not provide proper error recovery which could pose

     a problem for some users.





     ZMODEM



     File transfers utilizing ZMODEM protocol via  PC  Pursuit  yielded  an

     average  transfer  rate of 93%. ZMODEM performs well in the PC Pursuit

     environment at the default settings. Depending on  the  type  of  user

     equipment,  ZMODEM  options  may need to be modified to permit optimum

     throughput. The ZMODEM command line used in our test configuration was

     simply as follows:





         Uploads:     DSZ port 1 rz

         Downloads:   DSZ port 1 sz





     The  X.3  PAD  parameters  which  provide  optimum   performance   are

     1:0,4:10,5:1, 7:8,12:1. In addition, flow control (XON/XOFF) should be

     enabled  at  the user PC and the host. It should be noted that in most

     cases these additional PAD parameters are optional and  need  only  be

     employed if the user is experiencing difficulty transferring files via

     ZMODEM.



     The  following  page  summarizes  file  transfer  performance  of  the

     protocols tested. The protocols are  listed  in  order  (PCP  best  to

     worst)  in  two categories: 1) performance via direct connect, 2) per-

     formance via PC Pursuit utilizing the  recommended  hunt  confirm  and

     parameter  settings  shown.  It  should  be  noted  that  the optional

     parameters need only be employed if a user experiences  problems  with

     transferring a particular file.









































                                      - 3 -                                













                      SECTION 3.: File Transfer Procedures

                      ------- -   ------------------------





     This  section  outlines  the step by step procedure for executing file

     transfers via PC Pursuit. These procedures must be followed exactly to

     achieve optimum transfer rates. The optional X.3 parameters  shown  on

     the  previous  page  indicates  the  parameters which provide the best

     transfer rates as well as reduce the possibility of aborts.







     STEP 1.:    Set PC communications software to 8 bits, no parity,

                 1 stop bit, full duplex. At this time, the user may wish

                 disable or enable local (XON/XOFF) flow control depending

                 on the type of protocol to be used.



     STEP 2.:    Dial local rotary with the communications software

                 set at the desired speed.



     STEP 3.:    Upon connect use the correct hunt confirm sequence:

                     At 300/1200bps use - <CR D CR>

                     At 2400bps         - <@ D CR>

                     NOTE: "D" MUST BE UPPER CASE.



     STEP 4.:    At prompt "TERMINAL = " enter  <D1> and return.



     STEP 5.:    At the "@" prompt enter the destination mnemonic,

                 out-dial speed, ID and password.  It is important

                 that out-dial speed matches in-dial speed.

                 DO NOT MIX IN-DIAL AND OUT-DIAL SPEEDS.



     STEP 6.:    If OPTIONAL X.3 pad parameters are to be changed, do

                 so at this point by entering <@ CR>. To set parameters

                 as prescribed perform the following:



                 To set parameters enter <SET parameter,parameter>

                     Example: SET 7:8,4:10,5:1,7:8,12:1

                 To read parameters enter <PAR?>



                 Return to out-dial port by entering

                 <CONT>.



     STEP 7.:    Upon connecting to the destination pad, ensure

                 communication with the out-dial modem by entering <ATZ>.

                 The destination modem will respond with "OK".



     STEP 8.:    Enter <ATD> and the local number you wish to dial.



     STEP 9.:    Queue host file transfer and start file transfer.



     Please note that these are the basic steps needed to achieve  success-

     ful  file  transfers.  Since  communications  software  may  vary from

     package to package, additional steps may be  needed  to  initiate  the

     start of the file transfer at the user software level.









                                      - 5 -                                













                              SECTION 4.: Summary

                              ------- -   -------





     Extensive testing has resulted in identifying the expected performance

     of  six  file  transfer  protocols  when  used  with PC Pursuit. These

     protocols have been  determined  to  perform  satisfactorily  with  PC

     Pursuit  when  the  correct hunt-confirm, terminal type and parameters

     are employed.



     It is the recommendation of Field Operations  that  customers  be  in-

     formed of the correct logon procedures and the protocols which provide

     the  most  reliable  file transfers. Customers should also be reminded

     that PCP users can expect a small degree of  network  delay  which  is

     considered  a  common  characteristic  of packet switched networks. In

     addition, users should also be informed that poor quality voice  grade

     telephone lines can adversely affect file transfer sessions.



     Field  Operations is one of many Telenet groups dedicated to providing

     customers with complete support for PC Pursuit. Field Operations  will

     offer assistance with file transfer problems providing the customer is

     willing  to  release a copy of the problem software as well as provide

     the pertinent information necessary to resolve the problem.









































































                                      - 6 -                                













                          SECTION 5.: Troubleshooting

                          ------- -   ---------------







     If you are experiencing trouble with PC Pursuit  check  the  following

     items:



     * Verify the correct hunt-confirm sequence



     * Verify user software comm parameters are set to 8 bits, no parity and

       1 stop bit.



     * If problems with file transfer only, try the optional ITI PAD parameters.







     If all else fails, then call Telenet Customer Service and report the

     problem. Be prepared to provide the following:



      * Type of communication software

      * Type of PC, make and model

      * Type of modem

      * Call origin (in-dial city)

      * Call destination (out-dial city)

      * Speed in

      * Speed out

      * Type of session

      * Time of failure

      * Date of failure

      * Point of failure in session

      * Out-dial number

      * Network Addresses (shown at login, and by command "STAT"

                           when connected to out-dial port)



     Additional information may be required depending on the nature of

     the problem.













































                                      - 7 -                                





                                  FILE TRANSFER

                              PERFORMANCE STATISTICS



  General Communication Parameters = 8 bits

                                     1 stop bit

                                     N no parity



  Terminal Type = D1



  |          PERFORMANCE STATISTICS DIRECT CONNECT       |
  |                                                      |
  |                                                      |
  |                                                XFR   |
  | PROTOCOL    SPEED  SECONDS      CPS       BPS  RATE  |
  |======================================================|
  |                                                      |
  | ZMODEM UP    1200   ***394   114.36   1143.55   95%  |
  | ZMODEM UP    2400   ***199   226.41   2264.12   94%  |
  | ZMODEM DN    1200   ***394   114.36   1143.55   95%  |
  | ZMODEM DN    2400   ***196   229.88   2298.78   96%  |
  |                                                      |
  | SEALINK UP   1200   ***418   107.79   1077.89   90%  |
  | SEALINK UP   2400   ***200   225.28   2252.80   94%  |
  | SEALINK DN   1200   ***400   112.64   1126.40   94%  |
  | SEALINK DN   2400   ***205   219.79   2197.85   92%  |
  |                                                      |
  | WXMODEM UP   1200   ***405   111.25   1112.49   93%  |
  | WXMODEM UP   2400   ***205   219.79   2197.85   92%  |
  | WXMODEM DN   1200    **277    96.12    961.16   80%  |
  | WXMODEM DN   2400   ***216   208.59   2085.93   87%  |
  |                                                      |
  | YMODEM UP    1200   ***387   116.42   1164.24   97%  |
  | YMODEM UP    2400   ***194   232.25   2322.47   97%  |
  | YMODEM DN    1200   ***385   117.03   1170.29   98%  |
  | YMODEM DN    2400   ***199   226.41   2264.12   94%  |
  |                                                      |
  | KERMIT UP    1200   ***553    81.48    814.76   68%  |
  | KERMIT UP    2400   ***287   156.99   1569.90   65%  |
  | KERMIT DN    1200   ***571    78.91    789.07   66%  |
  | KERMIT DN    2400   ***295   152.73   1527.32   64%  |
  |                                                      |
  | XMODEM UP    1200   ***425   106.01   1060.14   88%  |
  | XMODEM UP    2400   ***219   205.74   2057.35   86%  |
  | XMODEM DN    1200   ***436   103.34   1033.39   86%  |
  | XMODEM DN    2400   ***228   197.61   1976.14   82%  |
   =======================================================


  * Optional PAD parameters which optimize performance

  ** File size = 26624   *** File size = 45056




|                                               PERFORMANCE STATISTICS VIA PCP                    
                  |

|                                                                                                 
                  |

|                                                HUNT             OPTIONAL ITI                    
                  |

|                                         XFR  CONFIRM   FLOW     X.3 PAD                         
                  |

| PROTOCOL   SPEED SECONDS    CPS      BPS  RATE  SEQUENCE CONTROL  PARAMETERS               NOTES
                  |

|=================================================================================================
==================|

|                                                                                                 
                  |

| ZMODEM UP   1200  ***399  112.92  1129.22  94%  CR D CR  XON/XOFF *1:0,4:10,5:1,7:8,12:1 *Host a
terminal XON/XOFF |

| ZMODEM UP   2400  ***200  225.28  2252.80  94%   @ D CR  XON/XOFF *1:0,4:10,5:1,7:8,12:1 *Host a
terminal XON/XOFF |

| ZMODEM DN   1200  ***398  113.21  1132.06  94%  CR D CR  XON/XOFF *1:0,4:10,5:1,7:8,12:1 *Host a
terminal XON/XOFF |

| ZMODEM DN   2400  ***204  220.86  2208.63  92%   @ D CR  XON/XOFF *1:0,4:10,5:1,7:8,12:1 *Host a
terminal XON/XOFF |

|                                                                                                 
                  |

| SEALINK UP  1200  ***420  107.28  1072.76  89%  CR D CR  XON/XOFF *7:8,1:0               *Host a
terminal XON/XOFF |

| SEALINK UP  2400  ***202  223.05  2230.50  93%   @ D CR  XON/XOFF *7:8,1:0               *Host a
terminal XON/XOFF |

| SEALINK DN  1200  ***402  112.08  1120.80  93%  CR D CR  XON/XOFF *7:8,1:0               *Host a
terminal XON/XOFF |

| SEALINK DN  2400  ***207  217.66  2176.62  91%   @ D CR  XON/XOFF *7:8,1:0               *Host a
terminal XON/XOFF |

|                                                                                                 
                  |

| WXMODEM UP  1200  ***406  110.98  1109.75  92%  CR D CR  XON/XOFF *7:8,1:0               *Host a
terminal XON/XOFF |

| WXMODEM UP  2400  ***263  171.32  1713.16  71%   @ D CR  XON/XOFF *7:8,1:0               *Host a
terminal XON/XOFF |

| WXMODEM DN  1200  ***469   96.07   960.68  80%  CR D CR  XON/XOFF *7:8,1:0               *Host a
terminal XON/XOFF |

| WXMODEM DN  2400  ***214  210.54  2105.42  88%   @ D CR  XON/XOFF *7:8,1:0               *Host a
terminal XON/XOFF |

|                                                                                                 
                  |

| YMODEM UP   1200  ***467   96.48   964.80  80%  CR D CR     NONE  *7:8,1:0                      
                  |

| YMODEM UP   2400  ***252  178.79  1787.94  74%   @ D CR     NONE  *7:8,1:0                      
                  |

| YMODEM DN   1200  ***461   97.74   977.35  81%  CR D CR     NONE  *7:8,1:0                      
                  |

| YMODEM DN   2400  ***263  176.00  1760.00  73%   @ D CR     NONE  *7:8,1:0                      
                  |

|                                                                                                 
                  |

| KERMIT UP   1200  ***558   80.75   807.46  67%  CR D CR  XON/XOFF *7:8,1:0                      
                  |

| KERMIT UP   2400  ***285  158.09  1580.91  66%   @ D CR  XON/XOFF *7:8,1:0                      
                  |

| KERMIT DN   1200  ***579   77.82   778.17  65%  CR D CR  XON/XOFF *7:8,1:0                      
                  |

| KERMIT DN   2400  ***297  151.70  1517.04  63%   @ D CR  XON/XOFF *7:8,1:0                      
                  |

|                                                                                                 
                  |

| XMODEM UP   1200  ***985  45.74   457.42   38%  CR D CR     NONE  *7:8,1:0                      
                  |

| XMODEM UP   2400  ***636  70.84   708.43   30%   @ D CR     NONE  *7:8,1:0                      
                  |

| XMODEM DN   1200 ***1001  45.01   450.11   38%  CR D CR     NONE  *7:8,1:0                      
                  |

| XMODEM DN   2400  ***636  70.84   708.43   30%   @ D CR     NONE  *7:8,1:0                      
                  |

==================================================================================================
===================


  * Optional PAD parameters wich optimize performance   ** File size = 26624   *** File size = 450
6



Time left = 39 minutes and 31 seconds
Current download area = pcp

Current upload area = upload
Allowable daily download limit = 4904507 bytes


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