NODES

Command

NODES -- Display / Modify the Nodes table.

Synopsis

N[odes] [call | *|+|C|F|H|I|O|N|P|Q|R|S|T]
N[odes] <A | V>    <call>
N[odes] < < | > >  <qual>

Description

The NODES command is used to list the contents of the Netrom nodes table in a variety of different ways, according to the format of the command.

Nodes may be listed in callsign or alias order, and wildcard searches may be performed on either field.

The display may be restricted to those nodes whose NetRom quality is greater or lesser than a specified figure, or to those who are netrom-only, time-only, obsolete and so on. Or the sysop may choose to display only those nodes for whom an IP address or round trip time is known, or those who have frames waiting, or those who have non-zero counters.

The command may also be used to find which nodes are routed via which neighbour node.

Options

N           List all nodes, excluding "hidden" ones
N *         List all nodes, incluing hidden ones
N +         List nodes with both time and qual metrics valid
N > <qual>  List nodes with NetRom Quality greater than <qual>
N < <qual>  List nodes with NetRom Quality less than <qual>
N <call>    List information and routes to target <call>
N A <call>  List nodes advertised by neighbour <call>
N C         List nodes by callsign instead of in alias order
N F         List nodes with a non-zero "Frames" count
N H         List nodes with a non-zero Hop count
N I         List nodes which have an IP address
N O         List Obsolete nodes
N N         List nodes whose only usable metric is Netrom
N P         List nodes whose position is known
N Q         List nodes which currently have frames queued
N R         List nodes for whom a RTT count is known
N S         List nodes with a position, RTT or frame count 
N T         List nodes whose only usable metric is Time
N V <call>  List nodes for whom preferred route is via <call>

Detail

When used without arguments, this command lists all the NetRom nodes (but not KA nodes) known to the router, except those "hidden" nodes whose alias begins with the hash (#) character.

If the argument is an asterisk (*), all nodes, including "hidden" nodes will be displayed.

If the argument is a known node call or alias (e.g. N MLVN), the preferred route to the specified node, and up to two alternative routes will be displayed. Other information, such as the position (in APRS format) and IP address will be displayed if known. The response looks like this:

	G8PZT:KIDDER} Nodes:
        Info for: MLVN:G4FPV
        Pos=5223.21N 00202.13W
 
        Routes to: MLVN:G4FPV  RTT=28  FR=3538  Q=0
          Qty Obs Pt Via      Stt Hop Obs2
        > 150  5   5 G4FPV   1.22  1   4 <
          110  5   9 GB7GH
            0  4   2 G1DKI-7

"RTT" stands for Round Trip Time and is a running average of the time (in seconds) taken to get a response from that node.

"FR" indicates the number of level 3 frames sent to that node.

"Q" is the number of Level 3 frames currently queued for that destination.

A chevron ">" in the left-most column indicates the currently active route.

"Qty" is the overall NetRom path quality to the target node.

"Obs" is the NetRom "obsolescence count", which shows how fresh the information It is a measure of how recently the route was heard about or used. It is usually reset to OBSINIT (usually 5) upon hearing a nodes broadcast from the neighbour node, and decrements by one every time XRPi makes a node broadcast (typically once per hour). If it drops below OBSMIN (usually 3) the route is considered to be obsolete.

"Pt" is the port number for the neighbour.

"Via" is the neigbour node via which the target is reached.

"Stt" is "Smoothed Trip Time", which is the average one-way transit time to the neighbour in seconds. This field may not be present in all cases.

"Hop" is the total no. of hops to the target via this neighbour. It is one more than the number of intermediate nodes. This field may not always be available.

"Obs2" is the obsolescence count for the time domain information (Stt & hops) which is learned via INP3. This info is maintained independently of NetRom "quality" metrics. A node may have obsolete quality metrics, but still have valid temporal metrics. The backward chevron "<" indicates the preferred route, which may differ from the route actually used at that instant.

If the requested nodecall or alias is not in the table, an error message results.

If the specified callsign or alias contains wildcards, a list of matching nodes will be displayed.

"N A <call>" displays the list of nodes "advertised" by <call>, i.e. those nodes the neighbour claims to be able to reach. This is not necessarily the same as the nodes *routed* via that neighbour, because some of the nodes may be advertised with better metrics by other neighbours.

"N C" displays nodes in callsign order instead of the standard alias order. If you wish the nodes to be displayed in callsign order by default, use SORTBYCALL=1 in XROUTER.CFG.

"N F" displays nodes with a non-zero "Frames" count. The frame count is only available for nodes with to whom XRPi has routed some traffic.

"N H" lists the nodes which have a non-zero "hop" count. This hop count is derived from actual measurements, rather than the "hypothetical" count derived from INP3, and is available for only a few nodes at most.

"N I" displays the nodes which have an IP address. In practice this list is likely to contain only XRouter, XRPi and X(Net) nodes.

"N O" lists the "obsolete" nodes, i.e. those for whom all metrics are too "stale" to be used. These nodes are probably off-line or otherwise unreachable.

"N N" displays the nodes whose only usable metric is NetRom quality, i.e. those for whom a trip time is unknown or has gone obsolete.

"N P" lists the nodes whose position is known. In practice, the only nodes which show in this list will be XRouter or XRPi.

"N Q" displays the nodes which currently have frames waiting to be delivered to them. The queues may be the result of link bottlenecks, and the figure is likely to change rapidly.

"N R" displays the nodes for whom a Round Trip Time is known. This is an average value for all connections between XRPi and the target node, and may differ from the current "hypothetical" trip time, derived from INP3 information. The RTT will only be available for nodes which XRPi has connected to.

"N S" displays the nodes for whom some "stats" are known, i.e. position, Round Trip Time or frame count.

"N T" lists the nodes whose only usable metric is Time, i.e. those which have a valid trip time, but for whom the NetRom quality is unknown or is considered obsolete.

"N V <call>" displays the nodes who would be routed via neighbour <call> at the current instant. This choice may change with time, as the metrics fluctuate.

Examples

N           - List nodes except those beginning with #
N *         - List nodes including those beginning with #
N MLVN      - Display routes to MLVN node
N V VK2DOT  - Display nodes routed via VK2DOT
N > 100     - Display nodes with qualities greater than 100

Availability

The NODES command is available to all users.