address for all.

   2.4  Type-of-Service

      Applications MUST select appropriate TOS values when they invoke
      transport layer services, and these values MUST be configurable.
      Note that a TOS value contains 5 bits, of which only the most-
      significant 3 bits are currently defined; the other two bits MUST
      be zero.

      DISCUSSION:
           As gateway algorithms are developed to implement Type-of-
           Service, the recommended values for various application
           protocols may change.  In addition, it is likely that
           particular combinations of users and Internet paths will want
           non-standard TOS values.  For these reasons, the TOS values
           must be configurable.

           See the latest version of the "Assigned Numbers" RFC
           [INTRO:5] for the recommended TOS values for the major
           application protocols.




 



RFC1123              APPLICATIONS LAYER -- GENERAL          October 1989


   2.5  GENERAL APPLICATION REQUIREMENTS SUMMARY

                                               |          | | | |S| |
                                               |          | | | |H| |F
                                               |          | | | |O|M|o
                                               |          | |S| |U|U|o
                                               |          | |H| |L|S|t
                                               |          |M|O| |D|T|n
                                               |          |U|U|M| | |o
                                               |          |S|L|A|N|N|t
                                               |          |T|D|Y|O|O|t
FEATURE                                        |SECTION   | | | |T|T|e
-----------------------------------------------|----------|-|-|-|-|-|--
                                               |          | | | | | |
User interfaces:                               |          | | | | | |
  Allow host name to begin with digit          |2.1       |x| | | | |
  Host names of up to 635 characters           |2.1       |x| | | | |
  Host names of up to 255 characters           |2.1       | |x| | | |
  Support dotted-decimal host numbers          |2.1       | |x| | | |
  Check syntactically for dotted-dec first     |2.1       | |x| | | |
                                               |          | | | | | |
Map domain names per Section 6.1               |2.2       |x| | | | |
Cope with soft DNS errors                      |2.2       |x| | | | |
   Reasonable interval between retries         |2.2       |x| | | | |
   Allow for long outages                      |2.2       |x| | | | |
Expect WKS records to be available             |2.2       | | | |x| |
                                               |          | | | | | |
Try multiple addr's for remote multihomed host |2.3       | |x| | | |
UDP reply src addr is specific dest of request |2.3       | |x| | | |
Use same IP addr for related TCP connections   |2.3       | |x| | | |
Specify appropriate TOS values                 |2.4       |x| | | | |
  TOS values configurable                      |2.4       |x| | | | |
  Unused TOS bits zero                         |2.4       |x| | | | |
                                               |          | | | | | |
                                               |          | | | | | |

















 



RFC1123                  REMOTE LOGIN -- TELNET             October 1989


3.  REMOTE LOGIN -- TELNET PROTOCOL

   3.1  INTRODUCTION

      Telnet is the standard Internet application protocol for remote
      login.  It provides the encoding rules to link a user's
      keyboard/display on a client ("user") system with a command
      interpreter on a remote server system.  A subset of the Telnet
      protocol is also incorporated within other application protocols,