Domain names for ISP infrastructure links

David Carmean dlc at
Tue Jan 7 22:21:32 UTC 1997

In one message, Paul Vixie wrote:

>        [<iface>.]<router>.<pop>.<toplev>

In another message, Philip J. Nesser II wrote:

> Alex.Bligh supposedly said:
> > 

> > <2 letter POP code> <router number> - <1 let card type> <card no>
> >   - <i/f number> [ - <sub i/f number> [ - <DLCI num> ]]
> >   [ <2 letter POP code> <router number> ]

> > TH1-S2-3-4-5-ME6
> Well I think this is the best suggestion I have seen but I have a few
> comments:
> 1.  I really like the addition of the final pop-router combo so its easy to
> follow connections.  This has been missing in other suggestions so I am
> curious as to what others think.

It doesn't tell you what interface on the upstream router it's talking 
to, so I don't see an advantage.

> 2.  Using an fixed width format as proposed keeps the maximum length (not
> including the domain suffix) short. Assuming 2 digit router/interface
> numbers and a four digit DLCI, the max length is 24 characters.  (Even if
> we allow 3 digits to router numbers we max at 29).  I would propose to add
> a little more information in the form of 1 letter types in from of the
> numbers (like a 'd' before the DLCI number).  Looking at the example above
> is marginally okay because all field are present but what if there was
> either no subinterface or no DLCI, how would you tell what the last number
> is supposed to mean?

Just personal preference here, but I think Paul's example is easier to 
grok, especially if you don't know the "convention" beforehand.  The 
similarity to DNS subdomain heirarchy lends itself directly to the 
router, then the slot, then the interface, and then the sub-interface/

> 3.  How do people feel about putting the speed of the link in the DNS name,
> I have seen one yea and one nay.  I am ambivilant, but leaning towards no,
> not for privacy but for administrative ease.  If I upgrade a connection I
> don't want to have to remember to change my DNS entries.
> 4. Are people actually interested in pursuing this formally?  If a spec was
> written would you change your DNS names to conform?  Would you be willing
> to set up a formal registration process with the IANA for 2(or 3) letter
> pop codes to be consistant?

I like the idea of using the ICAO/IATA identifier of the nearest 
(major) airport as Paul seems to have done.  All the work in 
defining them has already been done.

My question is: who's the audience for this info?  

David Carmean                                           <dlc at>
Avtel Communications, Santa Barbara, CA			+1-805-730-7740
  Opinions herein are those of the author only, unless otherwise noted

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