Subj : proposed new nodelist
To   : Haakan Karlsson
From : Goran Eriksson
Date : Fri Sep 12 2003 10:02 pm

 HK> A comma separated list is not very flexible, but instead inherently
 HK> quite rigid. A flexible format have to be built on field
 HK> identifiers, that is the only way to guarantee future extentions
 HK> without breaking existent next generation software. 

I believe that a comma separated list can be reasonably flexible provided that 
all software that process it is written with extensibility in mind. 


Among other things this means that processing software should from the very 
start be written to tolerate unknown fields.

Field identifiers (or rather field group identifiers) could be used to identify 
each group of connectivity related fields:

,505,GET,Lulea,Goran_Eriksson,\
*POTS*,46-920-257910,33600,XX,V34,\
*ISDN*,46-920-257910,64000,CM,XX,X75,\
*IBN*,getibn.nospam.se,CM,\
*ITN*,getitn.nospam.com:9999,CM,\
*ISE*,irex@get.nospam.com

where the \ only implies line-breaks which have been inserted here for clarity.

With this

1. I can specify different on-line hours for different connectivity types all 
in one nodelist entry.
2. I can specify different host names and different ports for IP protocols all 
in one nodelist entry.
3. I can specify different file request capabilities for different connectivity 
types all in one nodelist entry.

and a number of other things I haven't demonstrated above.

New connectivity field groups may be added (e.g. *AX25* for packet radio links) 
without any problems provided that older software understands to gently ignore 
the AX.25 connectivity group. The internal syntax of a connectivity field group 
can be freely defined as long as no ambiguities arise.


One advantage with a text file format is that it's easy to maintain the 
information in the nodelist with your favourite text editor.

--- 
 * Origin: GET, Lulea, Sweden, +46-920-257910 (2:201/505.1)

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