Visara LINCS Features - Manual (Page 39)

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Chapter 5. Host Connectivity
707021-001
DNS names have a hierarchical organization, consisting of domains nested within one another.
Names are written from bottom to top, with dots separating the levels.
The root of the tree is currently maintained by the Network Information Center. If you want to
join the Internet you must contact the NIC to get the authority to be a member. NIC will grant
you access and the root name server will be updated with this information. There is usually a
name server at each node in the DNS structure tree. A name is defined by listing each label
separated by dots all the way to the root label.
Labels must be 63 characters or less and domain names must be less than or equal to 255
bytes, however LINCS will limit the length of a DNS name in a query to 128 bytes. A canonical
name response received from the name server that is greater than 128 bytes will be retransmitted
fully in another query attempt. The label must start with a letter, end with a letter or digit, and
have as interior characters only letters, digits, and hyphen.
LINCS is compliant with RFC1035 and RFC1034
TELNET
TELNET hosts on a TCP/IP network can be accessed from all authorized CUT-type devices
on a LINCS node. Hosts can be attached locally or through a routed network. The TELNET
feature on LINCS provides physical connection to an Ethernet or token ring network. LINCS
can provide terminal server functionality for up to 256 TELNET sessions.
This allows a CUT terminal to “connect” to a TCP/IP host computer which supports TELNET
applications. The devices attached to a LINCS node appear as a client to the host TELNET
server application.
The TELNET session functionality is very similar to an ASCII session. The main difference is
the LAN connection provides a much faster communication link between a host computer and
a CUT terminal compared with the asynchronous ports on a LINCS node. Most ASCII features
supported by LINCS are supported by the TELNET feature. This includes ASCII Concurrent
Print and ECHO print.
LINCS allows configuration of up to 10 sessions per device. With the proper hardware installed,
any of the 10 sessions can be TELNET sessions. This allows one device to support up to 10
TELNET sessions concurrently. Each TELNET session can connect to any one of several IP
hosts concurrently. Up to 16 IP hosts classes are supported on each LINCS node. The session
connections can be distributed among the 16 IP hosts in any manner.
During the session the CUT terminal will emulate IBM 3101, DEC VT2XX, VT1XX, VT52,
DG210 and DG410 terminals. After connection, the interface to the user has the same look
and feel of an ASCII session.
TELNET sessions use the same translate tables and keyboard interface defined for ASCII
sessions. This enables the TELNET sessions to support all off-line and language features
provided for ASCII host sessions.
To disconnect the terminal from the TELNET host, you can use either method available to an
ASCII session. This includes EXSEL-D or disconnect via SETUP mode.
LINCS supports RFC854, RFC855, RFC856, RFC857, RFC860 and RFC1091.