RFC 2122 (rfc2122) - Page 3 of 11
VEMMI URL Specification
Alternative Format: Original Text Document
RFC 2122 VEMMI URL Specification March 1997
as specified in Section 3.1. of RFC 1738. If : is omitted, the
port defaults to 575 (client software may choose to ignore the
optional port number in order to increase security). The
part is optional and may be omitted.
This URL does not designate a data object, but rather a multimedia
interactive service. A VEMMI service starts a multimedia session
managing multimedia objects and interacting with the user during the
session. To the difference of other stateless protocols, the link
between the client and the server is usually maintained during the
whole session (although in some cases other mechanisms may be used,
see below).
The is the name of the VEMMI service to activate. This
field is not mandatory and could be omitted for example if the remote
host manages only one VEMMI service or activates a VEMMI service by
default when no service is specified. If this field is omitted in the
URL and the server requests it, it is assumed that the VEMMI client
software will prompt the user for it.
In addition, after the , optional attributes and values
(parameters) associated with the VEMMI service may be specified as
part of the URL. When present, each parameter (attribute/value pair)
is separated from each other and from the rest of the URL by a ";"
(semicolon). The name of the attribute and its value are separated by
a "=" (equal sign). If present, these fields are used to transmit
additional data useful for service selection or to request to perform
a specific processing. For example, the $USERDATA field can be
specified to transmit additional user-specified data to the VEMMI
service.
4) Client/server dialog during service selection
The VEMMI client will interpret the VEMMI URL to connect to the
remote host and to access the specified VEMMI service. After
connecting to the remote system, the host may prompt the VEMMI client
for service name and user identification.
Before starting the VEMMI session, a VEMMI terminal is in 'standard'
mode and may display the data received from the network in a videotex
or telnet terminal window. As the VEMMI session may be started
anytime during an interactive videotex or telnet session, the VEMMI
service selection is performed by a simple dialog between the client
and the server.
The service, username and password information are transmitted by the
client software to the host in answer to the corresponding requests
received from the host. The following behavior is expected from the
Mavrakis, et. al. Standards Track