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Cabletron Systems DMS-100 User Manual

Page 52

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52 Chapter 2: EIU messaging protocols

297-8991-910 Standard 03.01 August 1999

Internet Protocol

The IP control software supports the IP logic, which provides a connectionless
datagram service between hosts. The IP software is designed such that the
same modules provide IP host and IP router functionality. The IP layer
interfaces with the following:

transport layer protocols like TCP and user datagram protocol (UDP) for
providing data flow between transport layer and data link layer

address resolution protocol (ARP) for resolving IP address to subnet
address

Internet control message protocol (ICMP) for handling IP control
messages to and from other IP nodes

The IP routing table is maintained through static datafill in IP tables in DMS-
core and through dynamic routing information available either through
Routing Information Protocol (RIP) or ICMP redirect message.

The IP throttling process is responsible for transmitting queued IP datagrams
to destination nodes, based on the IP throttling configuration in the IP tables in
DMS-core.

Telnet

Telnet is an application protocol for remote terminal access. Telnet software is
implemented in two parts:

a server that resides on the accessed (host) computer

a client that resides on the accessing (remote) computer

The server program listens at a known port for connection from clients. After
a connection is established, the client redirects all keyboard input to the server,
which passes it on to the accessed program. The server intercepts all program
output, and redirects it to the client which prints it on the client machine screen.

The DMS-100 telnet server implementation has the following features:

remote access to the DMS-100 switch through telnet

increased maximum number of simultaneous telnet sessions supported on
the DMS-100 switch

logs that report on the telnet software

dynamic assignment of telnet sessions

Telnet functionality has been implemented in the DMS-100 switch to provide
access to the CI and the MAPCI, which are running on a DMS-core (CM),
from a workstation or other FTP-capable devices on an Ethernet LAN.