619 lines
26 KiB
HTML
Executable File
619 lines
26 KiB
HTML
Executable File
<HTML>
|
|
<!-- $Id$ -->
|
|
<HEAD>
|
|
<TITLE>The Distribution Nodelist.</TITLE>
|
|
</HEAD>
|
|
|
|
<!-- Background white, links blue (unvisited), navy (visited), red (active) -->
|
|
<BODY
|
|
BGCOLOR="#FFFFFF"
|
|
TEXT="#000000"
|
|
LINK="#0000FF"
|
|
VLINK="#000080"
|
|
ALINK="#FF0000"
|
|
>
|
|
<PRE>
|
|
| Document: FTS-0005
|
|
| Version: 003
|
|
| Date: February 7, 1996
|
|
| Maintainer: David Nugent, 3:632/348@fidonet
|
|
|
|
|
|
The Distribution Nodelist
|
|
|
|
Originally by Ben Baker
|
|
Amended by Rick Moore, 1:115/333@FidoNet, February 5, 1989
|
|
Amended by David Nugent, 3:632/348@FidoNet, February 27, 1996
|
|
|
|
|
|
| Copyright 1986-1996 by the FidoNet Technical Standards Committee.
|
|
All rights reserved. Duplication and/or distribution permitted
|
|
for non-commercial purposes only.
|
|
|
|
This document supersedes and replaces the document known under
|
|
| the names of FSC002, FSC-0002, and FTS-0002. Significant changes,
|
|
| which excludes mere formatting changes, to the previous version
|
|
| of this document have been "redlined" (marked with a vertical
|
|
| bar in the leftmost column).
|
|
|
|
This document defines the format and content of the nodelist for
|
|
the Public FidoNet Network (PFN) as published on Friday of each
|
|
| week. This format is historically known as the "St. Louis nodelist
|
|
| format".
|
|
|
|
The PFN is an international network of independently owned
|
|
electronic mail systems, most with interlocking electronic
|
|
bulletin board systems. The distribution nodelist, or simply
|
|
"nodelist", is the glue which holds the network together. It is
|
|
the PFN's "phone book" and it defines the top-level network
|
|
| structure and is the means by which FidoNet retains its integrity
|
|
| as a point-to-point mail network.
|
|
|
|
|
|
| THE NODELIST
|
|
|
|
The nodelist is published as an ASCII text file named
|
|
NODELIST.nnn, where nnn is a three digit number representing the
|
|
| day-of-year of the Friday publication date, with zeros filling
|
|
| positions to the left if necessary. This file is packed into a
|
|
| archive file named NODELIST.?nn, where 'nn' are the last two
|
|
| digits of day-of-year, and the character at the position of the
|
|
| '?' indicating the type of compression used. Conventions as to
|
|
| which compression method is used for the distributed nodelist is
|
|
| a matter of local policy and is usually determined by each zone's
|
|
| Zone Coordinator.
|
|
|
|
As stated above, NODELIST.nnn is an ASCII text file. It contains
|
|
two kinds of lines; comment lines and data lines. Each line is
|
|
terminated with an ASCII carriage return and line feed character
|
|
sequence, and contains no trailing white-space (spaces, tabs,
|
|
| etc.). The file is terminated with a DOS end-of-file character
|
|
| (character value 26 decimal, or "control-Z").
|
|
|
|
Comment lines contain a semicolon (;) in the first character
|
|
position followed by zero or more alphabetic characters called
|
|
"interest flags". A program which processes the nodelist may use
|
|
comment interest flags to determine the disposition of a comment
|
|
line. The remainder of a comment line (with one exception,
|
|
| treated below) is free-form ASCII text. There are five types of
|
|
| comments flags:
|
|
|
|
| ;S This is of particular interest to Sysops
|
|
| ;U This is of particular interest to BBS users
|
|
| ;F This should appear in any formatted "Fido List"
|
|
| ;A This is of general interest (shorthand for ;SUF)
|
|
| ;E This is an error message inserted by the nodelist generator
|
|
| ; This comment may be ignored by a nodelist processor
|
|
|
|
The first line of a nodelist is a special comment line containing
|
|
identification data for the particular edition of the nodelist.
|
|
The following is an example of the first line of a nodelist:
|
|
|
|
;A FidoNet Nodelist for Friday, July 3, 1987 -- Day number 184 : 15943
|
|
|
|
This line contains the general interest flag, the day, date, and
|
|
| three-digit (zero-filled) day-of-year number of publication, and
|
|
ends with a 5 digit decimal number with leading zeros, if
|
|
necessary. This number is the decimal representation of a check
|
|
value derived as follows:
|
|
|
|
Beginning with the first character of the second line, a
|
|
16 bit cyclic redundancy check (CRC) is calculated for the
|
|
entire file, including carriage return and line feed
|
|
characters, but not including the terminating EOF
|
|
character. The check polynomial used is the same one used
|
|
for many file transfer protocols:
|
|
|
|
2**16 + 2**12 + 2**5 + 2**0
|
|
|
|
The CRC may be used to verify that the file has not been edited.
|
|
The importance of this will become evident in the discussion of
|
|
NODEDIFF, below. CRC calculation techniques are well documented
|
|
| in various technical references, and will not be treated further
|
|
here.
|
|
|
|
The content of the remaining comments in the nodelist are
|
|
intended to be informative. Beyond the use of interest flags for
|
|
distribution, a processing program need not have any interest in
|
|
them.
|
|
|
|
A nodelist data line contains eight variable length "fields"
|
|
separated by commas (,). No space characters are allowed in a
|
|
data line, and underscore characters are used in lieu of spaces.
|
|
The term "alphanumeric character" is defined as the portion of
|
|
the ASCII character set from 20 hex through 7E hex, inclusive.
|
|
The following discussion defines the contents of each field in a
|
|
data line.
|
|
|
|
|
|
Field 1: Keyword
|
|
|
|
The keyword field may be empty, or may contain one of the
|
|
following:
|
|
|
|
Zone
|
|
|
|
Begins the definition of a geographic zone and define its
|
|
coordinator. All the data lines following a line with the
|
|
"Zone" keyword down to, but not including, the next
|
|
occurrence of a "Zone" keyword, are regions, networks, and
|
|
| nodes within the defined zone. Node entries defined
|
|
| immediately after the "Zone" keyword and before the next
|
|
| region or host entry are known as zone adminstrative nodes.
|
|
| These are allocated by the Zone Coordinator for use by nodes
|
|
| in the entire zone; for example, mail gateways between
|
|
| FidoNet zones.
|
|
|
|
Region
|
|
|
|
Begins the definition of a geographic region and defines
|
|
its coordinator. All the data lines following a line with
|
|
the "Region" keyword down to, but not including, the
|
|
next occurrence of a "Zone", "Region", or "Host"
|
|
keyword, are independent nodes within the defined region.
|
|
|
|
Host
|
|
|
|
Begins the definition of a local network and defines its
|
|
| network coordinator. All the data lines following a line
|
|
with the Host keyword down to, but not including, the
|
|
next occurrence of a "Zone", "Region", or "Host" keyword,
|
|
are local nodes, members of the defined local network.
|
|
|
|
Hub
|
|
|
|
Begins the definition of a routing sub-unit within a
|
|
multi-level local network. The hub is the routing focal
|
|
point for nodes listed below it until the next occurrence
|
|
of a "Zone", "Region", "Host", or "Hub" keyword. The hub
|
|
entry MUST be a redundant entry, with a unique number, for
|
|
one of the nodes listed below it, within its hub segment.
|
|
This is necessary because some nodelist processors
|
|
eliminate these entries in all but the local network.
|
|
|
|
Pvt
|
|
|
|
Defines a private node with unlisted number. Private nodes
|
|
are only allowed as members of local networks.
|
|
|
|
Hold
|
|
|
|
Defines a node which is temporarily down. Mail may be sent
|
|
to it and is held by its host or coordinator.
|
|
|
|
Down
|
|
|
|
Defines a node which is not operational. Mail may NOT be
|
|
sent to it. This keyword may not be used for longer than
|
|
two weeks on any single node, at which point the "down"
|
|
node is to be removed from the nodelist.
|
|
|
|
<empty>
|
|
|
|
| The field contains no text (not the sequence "<empty>"),
|
|
| and defines a normal node entry.
|
|
|
|
| Only one of these may be used in any individual data line.
|
|
|
|
|
|
Field 2: Zone/Region/Net/Node number
|
|
|
|
This field contains only numeric digits and is a number in the
|
|
range of 0 to 32767. If the line had the "Zone", "Region", or
|
|
"Host" keyword, the number is the zone, net, or region number,
|
|
and the node has an implied node number of 0. Otherwise, the
|
|
number is the node number. The zone number, region or net number,
|
|
and the node number, taken together, constitute a node's FidoNet
|
|
address.
|
|
|
|
Zone numbers must be unique. Region or net numbers must be unique
|
|
within their zone, hub numbers unique be within their net, node
|
|
| numbers unique within their net (and region, for regional
|
|
| independent nodes, zone for zone administrative entries). Duplicate
|
|
node numbers under different hubs within the same net are not
|
|
allowed.
|
|
|
|
|
|
Field 3: Node name
|
|
|
|
This field may contain any alphanumeric characters other than
|
|
commas and spaces. Underscores are used to represent spaces, and
|
|
a comma delimits the end of the field. This is the name by which
|
|
the node is known, usually as determined by the node or the
|
|
coordinator responsible for compiling the segment.
|
|
|
|
|
|
Field 4: Location
|
|
|
|
This field may contain any alphanumeric characters other than
|
|
commas and spaces. Underscores are used to represent spaces. This
|
|
field contains the location of the node. It is usually expressed
|
|
as the primary local location (town, suburb, city, etc.) plus the
|
|
identifier of the regional geopolitical administrative district
|
|
(state, province, department, county, etc.). Wherever possible,
|
|
standard postal abbreviations for the major regional district
|
|
should be used (IL, BC, NSW, etc.).
|
|
|
|
|
|
Field 5: Sysop name
|
|
|
|
This field may contain any alphanumeric characters other than
|
|
commas and spaces. Underscores are used to represent spaces. This
|
|
is the name of the system operator.
|
|
|
|
|
|
Field 6: Phone number
|
|
|
|
This field contains at least three and usually four numeric
|
|
sub-fields separated by dashes (-). The fields are country code,
|
|
city or area code, exchange code, and number. The various parts
|
|
of the phone number are frequently used to derive cost and
|
|
routing information, as well as what number is to be dialed. A
|
|
typical example of the data in a phone number field is
|
|
1-800-555-1212, corresponding to country 1 (USA), area 800
|
|
(inbound WATS), exchange 555, and number 1212.
|
|
|
|
Alternatively, this field may contain the notation
|
|
"-Unpublished-" in the case of a private node. In this case, the
|
|
| keyword "Pvt" must appear at the start of the line.
|
|
|
|
|
|
Field 7: Baud rate
|
|
|
|
This field contains one of the values: 300, 1200, 2400, 9600,
|
|
| 19200, or 38400.
|
|
|
|
| This baud rate is indicative only of the maximum baud rate that
|
|
| may be expected when connecting to a node and is generally of use
|
|
| only where a calling node needs to adjust the baud rate used to
|
|
| dial to the caller's modem speed in order to achieve a
|
|
| connection, a requirement that with modem technology available in
|
|
| 1996 is rarely if ever needed. This information is largely
|
|
| superseded by modem protocol flags (see next section) where any
|
|
| two nodes using a common protocol may have other expectations
|
|
| with regards to actual transfer rates. Use of the baud rate field
|
|
| alone is therefore depreciated.
|
|
|
|
|
|
Field 8 - Flags
|
|
|
|
This optional field contains data about the specific operation of
|
|
the node, such as file requests, modem protocol supported, etc.
|
|
Any text following the seventh comma on a data line is taken
|
|
collectively to be the flags field. The required format is zero
|
|
or more sub-fields, separated by commas. Each sub-field consists
|
|
of a flag, possibly followed by a value.
|
|
|
|
The following flags define special operating conditions:
|
|
|
|
Flag Meaning
|
|
|
|
CM Node accepts mail 24 hours a day
|
|
MO Node does not accept human callers
|
|
| LO Node accepts calls only from valid listed node
|
|
| numbers in the current FidoNet nodelist
|
|
|
|
|
|
The following flags define modem protocols supported:
|
|
|
|
Flag Meaning
|
|
|
|
| V21 ITU-T V21 300 bps full duplex
|
|
| V22 ITU-T V22 1200 bps full duplex
|
|
| V29 ITU-T V29 9600 bps half duplex
|
|
| V32 ITU-T V32 9600 bps full duplex
|
|
| V32b ITU-T V32bis 14400 bps full duplex
|
|
| V33 ITU-T V33
|
|
| V34 ITU-T V34 28800 bps full duplex
|
|
|
|
H96 Hayes V9600
|
|
HST USR Courier HST up to 9600
|
|
| H14 USR Courier HST up to 14400
|
|
| H16 USR Courier HST up to 16800
|
|
MAX Microcom AX/96xx series
|
|
PEP Packet Ensemble Protocol
|
|
| CSP Compucom Speedmodem
|
|
| ZYX Zyxel series
|
|
| VFC V.Fast Class
|
|
| V32T V.32 Terbo
|
|
|
|
NOTE: Many V22 modems also support Bell 212A.
|
|
|
|
If no modem flag is given, Bell 212A is assumed for 1200 bps
|
|
systems, ITU-T V22bis is assumed for 2400 bps systems.
|
|
|
|
|
|
The following flags define type of error correction available. A
|
|
separate error correction flag should not be used when the error
|
|
correction type can be determined by the modem flag. For
|
|
| instance, a modem flag of HST implies MNP, V32b implies V32 and
|
|
| V42b implies V42. Therefore MNP+HST, H14+MNP, H16+MNP, V32+V32b
|
|
| and V42+V42b flag pairs are redundant and should not be used.
|
|
|
|
Flag Meaning
|
|
|
|
MNP Microcom Networking Protocol error correction
|
|
| V42 ITU-T LAP-M error correction w/fallback to MNP 1-4
|
|
| V42b ITU-T LAP-M error correction w/fallback to MNP 1-5
|
|
|
|
|
|
The following flags define the type(s) of compression of mail
|
|
packets supported.
|
|
|
|
Flag Meaning
|
|
|
|
MN No compression supported
|
|
|
|
| NOTE: While FidoNet nodes usually exchange mail
|
|
| using a variety of different file compression
|
|
| formats negotiated between individual systems, the
|
|
| presence of this flag indicates the INABILITY TO
|
|
| RECEIVE MAIL compressed using the SEA ARC version 5
|
|
| compression format and/or named according to the
|
|
| ARCmail 0.6 mail bundle naming method. This is, by
|
|
| convention, the most common mail compression format
|
|
| in use within FidoNet. The presence of this flag
|
|
| would normally indicate that all mail should be sent
|
|
| uncompressed unless there is some overriding
|
|
| arrangement with the receiving system.
|
|
|
|
The following flags indicate the types of file and file update
|
|
requests supported.
|
|
|
|
Flag Meaning
|
|
|
|
XA Bark and WaZOO file/update requests
|
|
XB Bark file/update requests, WaZOO file requests
|
|
| XC Bark file requests, WaZOO file file/update
|
|
XP Bark file/update requests
|
|
XR Bark and WaZOO file requests
|
|
XW WaZOO file requests
|
|
| XX WaZOO file/update requests
|
|
|
|
|
|
The following flag defines gateways to other domains (mail
|
|
networks).
|
|
|
|
Flag Meaning
|
|
|
|
Gx..x Gateway to domain 'x..x', where 'x..x` is a string
|
|
of alphanumeric characters.
|
|
|
|
NOTE: Valid values for 'x..x' are assigned by the FidoNet
|
|
| International Coordinator or the person appointed as
|
|
| Internetworking Coordinator by the FidoNet
|
|
| International Coordinator. Current valid values of
|
|
'x..x' may usually be found in the notes at the end
|
|
| of the current FidoNet nodelist. The most common
|
|
| gateway flag is "GUUCP", to denote a gateway to the
|
|
| Internet mail system that gates on behalf of the
|
|
| fidonet.org internet domain.
|
|
|
|
|
|
The following flags define the dedicated mail periods supported.
|
|
They have the form "#nn" or "!nn" where nn is the UTC hour the mail
|
|
period begins, '#' indicates Bell 212A compatibility, and '!'
|
|
indicates incompatibility with Bell 212A.
|
|
|
|
Flag Meaning
|
|
|
|
| #01 Zone 5 mail hour (01:00 - 02:00 UTC)
|
|
#02 Zone 2 mail hour (02:30 - 03:30 UTC)
|
|
| #03 Zone 4 mail hour (08:00 - 09:00 UTC)
|
|
#09 Zone 1 mail hour (09:00 - 10:00 UTC)
|
|
#18 Zone 3 mail hour (18:00 - 19:00 UTC)
|
|
| #20 Zone 6 mail hour (20:00 - 21:00 UTC)
|
|
|
|
NOTE: When applicable, the mail period flags may be strung
|
|
together with no intervening commas, e.g.. "#02#09"
|
|
| or "!02!09". Only mail hours other than that
|
|
standard within a node's zone should be given. Since
|
|
observance of mail hour within one's zone is
|
|
mandatory, it should not be indicated.
|
|
|
|
|
|
The following flag defines user-specific values. If present,
|
|
this flag MUST be the last flag present in a nodelist entry.
|
|
|
|
Flag Meaning
|
|
|
|
Ux..x A user-specified string, which may contain any
|
|
alphanumeric character except blanks. This string
|
|
may contain one to thirty-two characters of
|
|
information that may be used to add user-defined
|
|
data to a specific nodelist entry.
|
|
|
|
| NOTE: Ux..x flags are the mechanism by which new flags may
|
|
| be experimentally introduced into the nodelist for a
|
|
| trial period to assess their worth. They are
|
|
| therefore of a temporary nature, and after their
|
|
| introduction they are eventually either promoted
|
|
| to a non-U flag or dropped from use altogether.
|
|
|
|
The FTSC recognizes that the FidoNet International Coordinator is
|
|
the ultimate authority over what appears in the FidoNet nodelist.
|
|
Also, FTSC is by definition a deliberative body, and adding or
|
|
changing a flag may take a considerable amount of time.
|
|
Therefore, the FidoNet International Coordinator may temporarily
|
|
make changes or additions to the flags as defined in this
|
|
document. The FidoNet International Coordinator will then consult
|
|
with FTSC over the changes needed to this document to reflect
|
|
these temporary changes.
|
|
|
|
|
|
The following are examples of nodelist data lines:
|
|
|
|
Host,102,SOCALNET,Los_Angeles_CA,Richard_Martz,1-213-874-9484,2400,XP
|
|
,101,Rainbow_Data,Culver_City_CA,Don_Brauns,1-213-204-2996,2400,
|
|
|
|
|
|
| THE NODEDIFF
|
|
|
|
| With more than thirty-five thousand nodes as of this date (1996),
|
|
| the nodelist, even in archive form, is a document of substantial
|
|
| size. Since distribution of the nodelist occurs via electronic
|
|
file transfer, this file is NOT routinely distributed. Instead,
|
|
| when a new nodelist is prepared weekly, it is compared with the
|
|
previous week's nodelist, and a file containing only the
|
|
differences is created and distributed.
|
|
|
|
| The distribution difference file, called NODEDIFF.nnn, where nnn
|
|
is the day-of-year of publication, is actually an editing script
|
|
which will transform the previous week's nodelist into the
|
|
current nodelist. A definition of its format follows:
|
|
|
|
The first line of NODEDIFF.nnn is an exact copy of the first line
|
|
| of LAST WEEK'S nodelist (i.e. the first line of the nodelist to
|
|
| which the current difference file applies). This is used as a
|
|
first-level confidence check to insure that the correct file is
|
|
being edited. The second and subsequent lines are editing
|
|
commands and data.
|
|
|
|
There are three editing commands and all have the same format:
|
|
|
|
<command><number>
|
|
|
|
<command> is a 1 letter command, one of A, C, or D.
|
|
|
|
<number> is a decimal number greater than zero, and defines the
|
|
number of lines to be operated on by the command. Each command
|
|
appears on a line by itself. The commands have the following
|
|
meanings:
|
|
|
|
Ann Add the following nn lines to the output file.
|
|
Cnn Copy nn unchanged lines from the input to the output
|
|
file.
|
|
Dnn Delete (or skip) nn lines from the input file.
|
|
|
|
The following illustrate how the first few lines of a
|
|
| hypothetical NODEDIFF.213 might look:
|
|
|
|
;A Friday, July 25, 1986 -- Day number 206 : 27712
|
|
D2
|
|
A2
|
|
;A Friday, August 1, 1986 -- Day number 213 : 05060
|
|
;A
|
|
C5
|
|
|
|
This fragment illustrates all three editing commands. The first
|
|
line is the first line from the previous nodelist, NODELIST.206.
|
|
The next line says "delete the first two lines" from
|
|
NODELIST.206. These are the identification line and the line
|
|
following it. The next command says "add the next two lines" to
|
|
NODELIST.213 at the "current" location. The two data lines are
|
|
followed by a command which says "copy five unchanged lines" from
|
|
NODELIST.206 to NODELIST.213. Notice that the first line added
|
|
| will ALWAYS contain the new nodelist CRC, so that the software
|
|
| applying the changes to the old nodelist may check the result of
|
|
| its editing.
|
|
|
|
Since only the differences will be distributed, it is important
|
|
to insure the accuracy of the newly created nodelist. This is the
|
|
function of the CRC mentioned above. It is sufficient for a
|
|
program designed to perform the above edits to pick the CRC value
|
|
from the first line added to the output file, then compute the
|
|
CRC of the rest of the output file. If the two CRCs do not agree,
|
|
one of the input files has been corrupted. If they do agree, the
|
|
probability is very high (but not 100%) that the output file is
|
|
accurate.
|
|
|
|
For actual distribution, NODEDIFF.nnn is packed into an archive
|
|
| file named NODEDIFF.?nn, where 'nn' are the last two digits of
|
|
| day-of-year, and '?' indicates the compression format used.
|
|
|
|
|
|
| NODELIST COMPILATION
|
|
|
|
| This section is included for tutorial reasons and is not intended
|
|
| as a definition of any specific method by which FidoNet MUST
|
|
| compile its weekly nodelist. It merely represents an attempt to
|
|
| document the method by which it currently does so. It is intended
|
|
| to be explanatory, and seeks to answer commonly asked questions,
|
|
| such as how the nodelist is compiled and where the information
|
|
| comes from, why the nodelists used in different FidoNet zones are
|
|
| not the same document, and why the difference file generated for
|
|
| use in one FidoNet zone cannot be applied to the nodelist
|
|
| generated for use in a different zone, even though the week
|
|
| numbers match.
|
|
|
|
| Nodelists are compiled via a distributed method, which follows
|
|
| the same structure as the FidoNet coordinator hierarchy. At the
|
|
| lowest level, network coordinators maintain a list of the nodes
|
|
| in their network and are responsible for the addition, removal
|
|
| and correction of individual node's listings in their "segment"
|
|
| (as portions of the full nodelist are called). In some larger
|
|
| networks, it is common for this job to be shared with hub
|
|
| coordinators appointed by the net coordinator, though the
|
|
| responsibility for those hub segments still remains with the
|
|
| network coordinator.
|
|
|
|
| At a nominated day during the week, before the regional level
|
|
| segment is submitted to the zone coordinator, individual net
|
|
| coordinators submit their segments to the regional coordinator
|
|
| who subsequently compiles these segments and transmits the merged
|
|
| copy to the zone coordinator. These are combined by the zone
|
|
| coordinator with the separate segments of other zones and
|
|
| compiled into that zone's version of the world nodelist. This
|
|
| world nodelist is then compared with the previous week's version,
|
|
| a difference file is generated and subsequently distributed
|
|
| throughout the zone.
|
|
|
|
| In some cases, in the interest of saving in transmission times
|
|
| and therefore costs, the compilation process itself may be better
|
|
| served by the submission of DIFFERENCE FILES rather than full
|
|
| net- or region-level segments. Each coordinator therefore retains
|
|
| a copy of the previously submitted segments and applies
|
|
| difference files to those to derive the new one. This process is
|
|
| exactly identical to the NODEDIFF/NODELIST scenario described
|
|
| earlier in this document, with the same first line and CRC
|
|
| validation method used to guard the integrity of the nodelist
|
|
| segments.
|
|
|
|
| For a number of reasons, it is important that publication of the
|
|
| nodelist be as timely as possible. These reasons include: the
|
|
| nodelist is a definitive list of valid FidoNet addresses that may
|
|
| receive mail, and must therefore be as correct and up-to-date as
|
|
| possible to save nodes the unnecessary expense of mail routed to
|
|
| possibly non-existing addresses; the nodelist contains the list
|
|
| of telephone numbers that may be called by any user of the
|
|
| FidoNet nodelist and should therefore be accurate so as not to
|
|
| unduly annoy owners of those phone numbers should a listed node
|
|
| go down and an unsuspecting telephone subscriber inherit the same
|
|
| telephone number.
|
|
|
|
| Given this constraint, the expense of international calls and the
|
|
| fact that FidoNet is a worldwide network that exists in many time
|
|
| zones, it may be unreasonable to expect the compilation of the
|
|
| nodelist to be delayed until each zone coordinator can transmit
|
|
| their most up-to-date zone segment to a central authority for
|
|
| compilation and subsequent redistribution in any week. For the
|
|
| sake of expedience, each zone instead maintains its own separate
|
|
| world nodelist which contains a compilation of the current zone's
|
|
| latest segments and including the most current copy to hand of
|
|
| all other FidoNet zone's segments. The zone level nodelist
|
|
| generated each week by each zone coordinator is then transmitted
|
|
| to all other zone coordinators for inclusion into their separate
|
|
| world nodelist as timing permits.
|
|
|
|
| In theory, then, the only difference between nodelists
|
|
| distributed in each zone in any week are accounted for by timing
|
|
| differences in the exchange of each zone's separate segment. In
|
|
| practice, other constraints may interfere with timeliness, such
|
|
| as the difficulty and expense of international telephonic
|
|
| communications. Also, another point of variance is introduced by
|
|
| the fact that each zone usually includes its own zone segment
|
|
| first into its world nodelist to assist - amongst other things -
|
|
| software that uses the nodelist for index generation. Some
|
|
| software in common use in FidoNet indexes the nodelist according
|
|
| to its sequential order (e.g. version 5 and 6 compiled nodelist
|
|
| formats), and including the current zone first before others will
|
|
| have a beneficial effect on software performance.
|
|
|
|
</PRE>
|
|
|
|
<A HREF="index.htm"><IMG SRC="../images/b_arrow.png" ALT="Back" Border="0">Go Back</A>
|
|
|
|
</BODY>
|
|
</HTML>
|
|
|