[Asterisk-Users] Opportunistic VoIP

[John Todd]

Willi -
   I think you misunderstand my point.  The fact that TRIP is not open 
to all parties is it's strength, and does not "break" it.  ENUM is 
for identifying individual destinations for completely-qualified 
phone numbers.  TRIP is for identifying gateways to aggregated blocks 
of phone numbers.  There is a difference between the absolute answers 
of ENUM and the relative answers of TRIP, which makes them extremely 
different in their use.  They can (and probably should) be used in 
the same dial plan examinations - if a search can't find an answer 
via ENUM, use TRIP and your call will get there on the 
cheapest/best/fastest/whatever path.  They compliment each other, and 
are not competitors, though there may be some overlap in their route 
tables.

   I may want to have pre-established relationships with certain 
providers.  Remember, most of the world won't be running end-to-end 
VOIP anytime soon, so I need to have PSTN carriers who can give me 
gateways into the TDM network.  Even between VOIP networks, TRIP has 
large benefits if I have big PBX systems with large ranges of 
numbers.  ENUM tells you exactly where to go; TRIP tells you a path 
if you don't have exact information.  ENUM cannot have "competing" 
answers for the same route question; TRIP allows local or remote 
weights to be assigned to individual paths or even to individual 
numbers.  From a programmatical point of view this may seem 
imprecise, but until many years in the future I believe this will be 
the most pragmatic approach to useful VOIP delivery.

JT


>John,
>
>On Wed, 2003-06-11 at 21:58, John Todd wrote:
>>  >This is slightly off-topic I suppose, but:
>>  ....
>>  2) The ENUM system is centralized.  TRIP can be established between
>>  two telephone systems, independently of any third party's cooperation
>>  or assistance.  Routes can be exchanged in any way that is acceptable
>>  to those two systems.
>>
>
>  I belive, that his is exactly the problem of TRIP.
>TRIP needs peering agreements between all providers.
>Compared to ENUM that can be queried without having
>a pre-established contract between all operators.
>This applies for queries as well as for providioning
>of the repository. Besides this, TRIP is way
>overloaded with attributes no one needs at the end.
>
>  My conclusion:
>TRIP breaks because it is not open to all parties.
>
>
>and this goes well along with Florian Overkamp's
>statement:
>
>>>  TRIP only makes it harder for widespread use to deal with
>>>  such things as number portability (can't ever do that with
>>>  IP, remember). As far as I can tell from the TRIP docs
>>>  this looks a lot like some big telco tries to make it more
>>>  difficult for customers to move to another telco and still
>>>  use their old number...
>
>Willi
>