The Packet Radio
“
2 N 1
”
Handbook
by
Buck Rogers
K4ABT
Section 1
;
Packet Radio “The Basics
”
Section 2
;
The X1J4 System Node Operator’s (SNO) Handbook
Section II
;
TheNET X1J4 System Node Operators Handbook
__ Page 33
Chapter 13 Section II
HOST MODE:
The Host mode supports a local terminal attached to the node. It permits the local terminal to access all of the same
capabilities that a remote user can access. In addition, it supports some specialized "host commands" available only from
the local terminal. For example, it allows
local entry of the password string used by the SYSOP command to validate sysop or network manager credentials.
1)
Esc C
Connects to the HOST node.
2)
Esc
P
Returns PASSWORD
3)
Esc
D
Disconnects (So does;
Bye, Quit, & RESET
)
Often a problem occurs at the end of a QSO when one station wants to disconnect, but not before making certain that the
other station has successfully received the first station's concluding information frames. This often resolves itself with a
last-minute flurry of closing remarks. TheNET
X1
solves this problem in a more respectable fashion.
If two stations are connected to one another via the network and one of the stations disconnects, TheNET
X1
automatically
maintains its connection to the other station until all in-transit information frames have been successfully delivered to that
station. TheNET
X1
disconnects only after all in-transit information has been delivered, or after 15 minutes has
elapsed without any "forward progress" in delivering such information.
AUTOMATIC ROUTING:
When you ask one node for a circuit to a distant node, your CONNECT command specifies the callsign or identifier of the
destination node, but the routing is handled automatically by TheNET
X1
. Automatic routing is handled by the Routing
Manager, and is controlled by its routing table.
The routing table within a node contains a list of all other nodes "known" to the node, together with their mnemonic
identifiers. You can ask to see this list by using a parameter NODES command. The routing table can keep track of
hundreds of other nodes (limited only by the size of available memory and any constraints imposed by the network
manager).
If you want to connect to an especially distant node, it is possible that your local node doesn't know of its existence as it is
not listed in the local NODES display.
In this case, you can use CONNECT to obtain a circuit to a known node nearer the desired destination, and then issue
another NODES command to get a list of the nodes known to that node. This process can be repeated if necessary. For
each known node, the routing table can contain up to three alternate ways to route traffic to that node. The node knows the
quality of each alternate route, and always attempts to use the "best" (i.e., highest quality) route to a destination. However,
if a node or path becomes unusable due to equipment failure or poor propagation, the Routing Manager automatically
switches to an alternate route (if available) to circumvent the outage. Such routing changes are handled dynamically,
usually without disrupting circuits in progress.
The routing table maintained by each node consists of two dynamically allocated threaded lists: the destination list and the
neighbor list. The destination list contains an entry for every other node "known" to this node. This is the list displayed by
the NODES command. The neighbor list contains an entry for only those "neighboring" nodes to which this node has a
direct link.
