Re: Send-N draft: draft-bellis-enum-send-n-02 published

[email protected] said:
> [btw, the original reasoning for using relative rather than absolute was 
> to avoid the need to regenerate the RRs if a portion of the number space 
> gets moved into a new prefix of different length]

This is something that has happened before and might happen again - more
importantly, there may well be a period of parallel running - so it was
worth taking into consideration.

> For the UK we've determined that once we've got as far as +44, a maximum 
> of just *two* Send-N lookups are required.
> 
> There's one particularly short number in our E.164 plan (+448001111).  So 
> looking up 4.4.e164.nicc.org.uk would return a Send-N of 7 (or =9). Having 
> received those further 7 digits that happens to be sufficiently far down 
> the tree that the next lookup will return either 2 (=11) or 3 (=12)

or 1 (=10) in a few cases.

> and 
> either of those will be the final result.

That appears to be the case right now. It's possible that there will be
some edge cases in the future where there will be one more lookup (that is,
the sequence is =9, =11, =12, result). These will be transitional, though,
as a particular number space is dynamically lengthened.

>> What also concerns me is this paragraph in section 5:
>> 
>>    information supplied by the local numbering plan administrator.  It
>>    is expected however that Send-N records would be synthesised
>>    automatically by the DNS server based on the information currently
>>    stored in its ENUM database.
>> 
>> Does "synthesised automatically" express the intent to generate these
>> responses on-the-fly or prior to loading the DNS zone, based on some
>> "ceterum censeo":
> 
> In the authoritative server they'd probably be created as the zone is 
> populated rather than in real-time.  I'll rephrase that.  In secondaries 
> they'd be part of the IXFR data, just like any other RR.

In other words, the intent is that when new data is entered into the
primary authoritative server, a process would be run that calculates the
Send-N records based on that data and the existing contents. Those records
would then be added to the server in the normal way. No, this wouldn't be a
standard DNS server doing this.

-- 
Clive D.W. Feather  | Work:  <[email protected]>   | Tel:    +44 20 8495 6138
Internet Expert     | Home:  <[email protected]>  | Fax:    +44 870 051 9937
Demon Internet      | WWW: http://www.davros.org | Mobile: +44 7973 377646
THUS plc            |                            |