AW: [enum-wg] COCOM & ENUM ...
Conroy, Lawrence (SMTP) lwc at roke.co.uk
Tue Dec 14 11:40:34 CET 2004
Hi Jim, Richard, folks, I beg to differ with my esteemed colleague Jim. I would be very surprised if an end user's terminal queried carrier anything, and would be even more surprised if it received a response. This is akin to suggesting that if my phone fired off an INAP query it would receive a response. With SCTP it might be theoretically possible, but I don't expect anyone would be listening. In the "new wine in old skins" world of NGNs, the infrastructure might make queries as part of a routing process, and one service provider would almost certainly get a different answer from the one responsible for the target resource (i.e. the "destination" service provider will probably be running a split horizon system), but would my SIP phone get ANY such information? Private and Public are the wrong terms - if service providers share some information to facilitate routing of communications sessions, this does not make that information public (e.g. available to anyone anywhere on the Internet). It's shared between carriers. I sure hope that their infrastructure doesn't roam - the bean counters would not be happy. all the best, Lawrence On 14 Dec 2004, at 10:15, Jim Reid wrote: >>>>>> "Richard" == Stastny Richard <Richard.Stastny at oefeg.at> writes: > > Richard> I fully agree and this is one of the problems I see by > Richard> introducing carrier E**M via a backdoor in e164.arpa. If > Richard> I am a carrier, especially a carrier acting on an > Richard> international basis, I want to implement routing > Richard> mechanisms within my network and with other networks > Richard> (peers) without having to go to a NRA begging first to > Richard> opt-in in e164.arpa and second to behave according to > Richard> various and different national rules. > > Richard, these points are undoubtedly true. However they have nothing > whatsoever to do with the choice of domain name for carrier ENUM. So > far, nobody has presented any compelling reason why another domain > name is needed for carrier ENUM. [Perhaps that discussion is going on > behind closed doors at ETSI or somewhere like that.] Sure, carrier > ENUM shouldn't be in the public e164.arpa tree. This doesn't stop an > operator from creating their own private e164.arpa tree, populating > that with whatever it likes and then making sure the applications on > the operator's net queries the private tree rather than the public > one. This setup is known as split DNS and is very common. Most large > companies do this. What we see on the internet for bt.com (say) will > be very different from what someone inside the BT network sees. > > What *is* important is that there's a single domain name and a single, > consistent name space. Many of the applications and services -- eg > VoIP and SIP -- that will be used by telcos will also be used on the > public internet. Suppose I'm developing or selling and supporting some > ENUM-aware SIP application. I don't want to have the complexity and > expense of needing to configure it to do ENUM-like lookups in > foobar.at if the box lives in Telekom Austria's net today or > vf.enum.egpp.net if that's where Vodafone's chosen to anchor its > carrier ENUM tree this week. And as for an ENUM-aware SIP client in a > mobile phone that roams between operators... Or flips between 802.11 > and GPRS nets... > > Richard> A carrier E**M implementation does not need a tier 0 and > Richard> tier 1, and it is questionable if it needs a tier 2. It > Richard> needs a centralisized database operated by someone, and > Richard> who this is will be decided by the community as will be > Richard> the other rules. > > The Tier-N jargon is probably inappropriate. However the roles might > not be. And I'm not sure a centralised database for carrier ENUM is > viable. It has obvious attractions: carriers sharing a common > infrastructure for example. OTOH, it brings problems too. Figuring out > who operates that infrastructure and how it gets paid for will be > entertaining. A centralised database could well mean telcos expose > their customer and call routing data to each other. Which is unlikely > to get much acceptance. >
[ enum-wg Archives ]