Friday, February 25, 2005

NEXT Carrier/Infrastructure ENUM in launched launched a Carrier/Infrastructure ENUM system in See also at The Register. I also include the English Version of the press release at the end of this post..

So what? Another Carrier/infrastructure ENUM application?

As some may know, there exist already such solutions , so what's the difference?

Most other applications are within walled gardens, between groups of peering carriers (e.g. cable operators, mobile operators, etc.). Either the end-points are not accessible from the public Internet and/or the DNS tree is also not accessible. This is the first ENUM application where every provider may participate (provided he signs the MoU and most of the providers also provide their customers public SIP URIs (real VoIP according to Henry Sinnreich), although the solution also offers the providers a possibilty to offer their data only to known peers and also to anonymize the data.

So why not do this in as intended?

The Register states clearly the reason:

The ENUM standard, also know as, is organised along the lines of the traditional numbering plan - and is therefore controlled by national regulators and, internationally, by the International Telecommunication Union. This has slowed progress. It is increasingly clear that VoIP providers will not wait for the official ENUM.

It has not slowed progress, it seems to stall it.

ENUM in has two basic problems:

Problem One: Country Opt-in
Problem Two: User Opt-in

In detail:

The IAB contacted the ITU-T regarding and the ITU-T, although reacting fast, and doing their part well, could only do what the ITU-T could do, namely declaring the rest as national matter.

So the ball was with the national regulators. Many regulators did not do anything, although quite a number re-acted and did what modern regulators do in such a case, they launched a consultation.

A consulation is asking the public (basically the people you know and have contact with) on their opinion - so the regulators in principle asked the telcos and sometimes also the ISPs.

The answers from most telcos was basically a replay of the answer the DARPA got from AT&T when asked if they want to build the Internet:

1. This will never work (We are the experts, this is all very complicated and if we would know a better method we would not spend so much money on the existing (e.g. SS7 and IN) systems.

2. If we are wrong and it works by chance, there will be no business case

3. If we are wrong again, an it is a business by chance, it will cannibalize our existing business (this argument was not spoken out, the first two where sufficient in most cases).

The ISPs asked at this time had no clue on telephony or VoIP at all or did not want to get in competition with telcos already.

Since VoIP was already reaching the horizon in some countries, and some telcos are not so sure about it, they showedat least interest: Let's establish a forum of interested parties looking at the issues to be solved. Most countries went this way and are still there by trying to solve all ENUM related issues first. In some countries there was finally a place where on can rant about the Internet situation in general and want all issues solved first before ENUM can be implemented: e.g. spam, spit, privacy, security, DoS-attacks, QoS, world hunger, global warming, ...

In some countries even trials where launched (to find out if the DNS works) and after 3 years they still are not quite sure. In some countries trials where launched even without the help of the regulator and without an official delegation and are quite successfull (see Asia).

Or as James Seng said:

Some countries have a delegation in and do not know what to do with it, and others know what to do, but do not get a delgagtion.

Finally some countries got over all these hazzles, with the help of the ccTLDs and a friendly and understanding regulator and are now stuck with the other problems:

1. How to overcome Metcalfe's Law
2. How to explain this to the end-users and enterprises (because they have to opt-in and also basically have no clue to what they should opt-in).

And if you get over this hurdle, the end-user or the enterprise asks you:
And whom can I reachnow in ENUM?

You have then to answer honestly: hmm, ehh, basically nobody, because in other countries they will maybe, eventually, if at all, launch this service in 2006, or maybe later, or never.

Since the end-user is clueless, they only way to sell ENUM seems to be in a bundle with a VoIP service and/or with a IP Communications service and this can only be sold by VoIP and IPC providers.

So Carrier/Infrastructure ENUM is a way out to overcome this problem and it may even mot conflict with ENUM in

There is of course the problem with applications like everbody can do this (if Thilo can do it;-) and therefore there will be no unique global system for VoIP peering.

This is the reason why ETSI is proposing to create a second tree in .arpa for provider use, but there seems to be no interest( yet), maybe until it is too late. Maybe also ETSI is talking to the wrong people.

Good night.

Press release:

DUESSELDORF, Germany, February 24, / - Starting today, offers public access to its voice over ip (VoIP) interconnection
service. Traditional local exchange carriers and VoIP service providers
connected to, benefit from cost savings by shifting their long
distance calls to the internet.'s huge database enables providers
to deliver calls to more then 100 million phone numbers at no cost, finally
delivering on the VoIP promise of significant savings.

Most of today's domestic and international phone calls are still delivered
over costly dedicated circuits. With VoIP technology maturing, the telecom
industry gears up to take advantage of low-cost phone calls delivered over
the Internet. In order to maximize savings, phone service providers are
facing the challenge to shift as many calls as possible to the Internet.
Until now, most players lacked a central piece of technology to do so; an
international database from which they could organise which phone service
would deliver calls to a certain destination number.

After more than six months of extensive field testing with a closed group
of market leaders in the VoIP arena, today announced the
immediate availability of its interconnection service. At launch time a
total of 14 connected service providers have submitted more than
100 million phone numbers to's database. These phone numbers
are spread over more than 160.000 different dialling prefixes covering
8 countries. has managed to secure broad support among relevant
players in most western markets. Its prominent members include (Sweden), (Switzerland), Magrathea Telecommunications
Limited (Great Britain), (Denmark), MS Networks S.A. (Luxembourg),
sipgate (Austria, Germany, Great Britain) and SIPphone Inc. (USA).

The launch of marks the world's first massive deployment of a
technology dubbed "Carrier-ENUM" by experts. Open Internet standards ensure
interoperability among service providers and ease deployment as almost all
of today's software already supports "Carrier-ENUM".

SIPphone, Inc.'s ( CEO and Founder, Michael Robertson,
praises the new system: " greatly simplifies interconnection
between VoIP providers around the globe, like SIPphone. We were excited
to see so many companies and organizations working together to hasten
the inevitable result of VoIP: free calls."

Founding father of, Thilo Salmon, a German VoIP expert, is
pleased with its take-up in the industry. "I am thrilled to see
gaining acceptance so rapidly. Free and low-cost phone calls are arguably
the driving force behind the VoIP revolution. is pleased to
cater to the booming VoIP industry to the benefit of both the service
providers and customers", says Salmon.


Steve Mancour
[netzquadrat] GmbH
+49 211 5800 3305

Another Vapor from Popular Telephony Vaporware 

Normally I would ignore PT since some time, but now I still try it, because I really want to know when they will be finally able to get a SW out that works. Some time ago they announced that they service is now "really" available, so I downloaded the PT Inspector once again, having already discovered that it is not upgrading itself automatically. The result was, that it showed the first time the possibility to login somewhere, but immediately replaced by a pop-up window announcing that it does not work behind a firewall.

Ok so I had to wait until a time when I was not, which was this week at APRICOT. What was the result: another pop-up window telling me that it does not work because I have no Internet connection. Of course the gnup.exe was the only program ton my laptop havin this esperience.

Today I found a blog entry on the VoIP Blog: PT Breaking News that PT is now working via NATs.

Ok, so I downloaded the PT Inspector once again and installed it, the PT Inspector downloaded the gnup.exe and the GNUP application tells me in a pop-up:

Network is down

Due to absence of Internet connection on your workstation we unable to communicate with the Peerio network right now. Blah blah ... (retry or quit).

The Pop-up is still there and retrying.

I just have one question to you idiots: How did I post this entry if I do not have an Internet connection?

But Dmitry is still invited to panels and making jokes. His GNUP/Peerio/whatever is a joke. He should first get his SW working. I am wondering that still people are taking this serious.

Wednesday, February 23, 2005


I already reported about the ENUM/SIP Demo here at Apricot. Yoshiro YONEYA presented at the APEET BoF on Tuesday the details about the demo. The presentation given can also be downloded there. Today finally the Admin Manual for the Hitachi WirelessSIP 5000 was distributed. Also on Tuesday Rich Shockey from Neustar gave an excellent ENUM Tutorial.

The conference started on Wednesday and had a stream organised also by APEET on Internet Telephony, chaired by James Seng and Yoshiro Yoneya. I had the honor to present ENUM in Austria in a morning session. In the afternoon a second session on ENUM was scheduled, presenting the status of ENUM in China, Japan, Singapore and Taiwan. Korea was missing, because Sungwoo Shin is in Geneva and presented the Korean Trial there. All presentations (including Korea) may be downloaded from here.

I was very impressed by all presentations, they all are very advanced and one may ask why they are still called trials. Some are already planning a pre-commercial phase, but why waiting?

I personally liked the presentation from Xiaodong Lee from China because of the downloads available on the website:
  • the ENUM Toolbar for IE, where one may query ENUM directly,
  • the IE Client, where you may enter an E.164 number in IE and get the webpage with Enumservice web:http (RFC 4002)
  • and finally my favorite, the Outlook client, which allows to enter an E.164 number in Outlook, if an Enumservice email:mailto is provided (see the (still stuck in IESG) draft-ietf-enum-msg-04).

The bell-heads view on VoIP: it is all about tariffs 

ComReg(the Irish regulator) issued last week a Consultation Paper called "Draft Directions to Enable Opening of Access to VoIP Services based on 076 Number Ranges".

Major points:

Ireland will also join the club with a national VoIP Number range (076).

The rest is primarily about tariffs:

Since there was no common agreement on the tarifs, two "price points" for retail tariffs will be defined:

One price point will be known as “VoIP Local” and have per minute rates of 4.07c, 1.04c and 1.04c for daytime, evening and weekend respectively. and use the number range 076-6.

The second price point will be known as “VoIP Sub-Local” and have per minute rates of 1.61c, 0.80c and 0.80c for daytime, evening and weekend respectively and use the number range 076-3.

A "VoIP national price point" generally felt to high.

Explanatory Note: It should be understood that this consultation and the draft Directions included in it are primarily concerned with PSTN-originated calls to VoIP services that use 076 numbers, i.e. inbound calls to 076 numbers. For these to function effectively, there must be contractual agreement concerning the retail amount charged by the PSTN originator to the caller, the termination amount paid to the recipient VoIP service provider and the retention amount to cover the call originating operator and possible transit operators.

VoIP to VoIP calls are not affected by this document nor are calls to non-076
number ranges.

Executive Summary:

In its response to consultation document ComReg 04/103, ComReg decided to designate a new non-geographic number range, based on the access code 076, for VoIP-based services. ComReg also decided in the document that the nongeographic settlement model (also known as the Number Translation Code model) should be used in respect of industry payments for calls to 076 numbers, with the retail tariff ceiling of this 076 range of numbers to be set at standard national rate.

In ComReg 04/103, ComReg accepted the strong preference expressed in industry responses to be allowed to negotiate its own arrangements for opening access, though with the caveat that ComReg would intervene if this process was unduly prolonged.

As few signs of progress were noted in opening of 076 access, ComReg intervened in January by asking eircom to submit a proposal based on three separate price points (national, local, and sub-local (equivalent to the rate used for 1891 Internet access)). These rates were to be submitted by Thursday 27th January, in time for an industry-wide consultative meeting called by ComReg. eircom submitted its proposal on Friday 28th January, based on a single price point (sub-local or 1891).

On the 2nd of February 2005, a consultative meeting of members of the VoIP industry was held at ComReg’s offices, following a widespread email invitation to all known interested parties. Of the 17 separate organisations that attended this meeting, both new and traditional voice service providers were represented. At this meeting ComReg presented its proposals for a choice of three initial price points.

The meeting consensus was that a single retail price point for 076 calls was preferred as an initial starting point but no consensus could be reached on what that price point should be, with some attendees preferring local call rate and others preferring a sublocal rate (i.e. equivalent to eircom’s 1891 rate). A national rate was generally felt to be too high.

The meeting concluded on the basis that ComReg would now consider the outcome including how to handle the disparity of views on preferred price positions. Following detailed internal discussions, ComReg has concluded that despite the meeting’s preference for a single price point, it would be impossible to meet the needs of both groupings i.e. those preferring local and those preferring sub-local retail rates. Accordingly, ComReg concludes that offerings should be available for both of these values (based on 076-X and 076-Y1) and in order for this to be
implemented as quickly as possible it is necessary to direct those affected to undertake the necessary work. The outcome will:
• Offer enhanced choice to Service Providers (and through them to the consumer);
• Meet ComReg’s stipulation in ComReg 04/103 that prices must not exceed national rate while also meeting industry’s wish for local rate or less;
• Facilitate efficient billing of disparate rates (i.e. using separate 076 number ranges);
• Meet as closely as possible the wishes of industry to reduce the number of price points.

Having arrived at these conclusions on the framework, it is next essential to quickly move to the actual operational opening of services, based on the 076 numbers. From 1 X and Y are any suitable digits; ComReg has proposed 3 and 6, respectively. experience since October 2004, it is unlikely that timely progress will be made without Direction by ComReg. Accordingly, this consultation proposes a set of draft Directions aimed at moving the process forward and all interested parties are invited to submit their views on these.

Tuesday, February 22, 2005

Responses to the UK DTI ENUM Consultation 

The UK ENUM DTI started an consultation on ENUM last year.

The first draft of the responses received are now available at the DTI website:


APRICOT 2005 and the ENUM/SIP Demo 

After spending the last week in Geneva at ITU-T SG2 (report to follow since it is still going on), I am spending this week in Kyoto at the APRICOT 2005. I am invited as a speaker to the conference - IP Telephony stream C1-1 - to talk on Wednesday about "ENUM in Austria - A status report of the first commercial ENUM implementation".

I already met many friends, e.g. Rich Shockey, giving a Tutorial on Tuesday on "ENUM Technology", and of course James Seng, one of the key players here giving presentations all over the place (must have been a challenge for the organizers not to schedule James twice at the same time ;-). James is of course enthusiastic over his APEET SIP/ENUM showcase he is running here. For more info on the trial see James Seng blog. Of course I also had to get a WiFI phone, but beeing late I only got the second choice (the phones without the USB cable, so you have to configure it on the phone). At the booth I met Desiree Miloshevic (AFILIAS) and Ching Chiao from TWNIC, and since James took care that the batteries of the phones are powered and the phones are preconfigured, we could try it out immediately. The rial is running nice and they also managed to get connectivity to some Asian countries and with the help of Patrik and Jeff also to Sweden and the US. One problem with the phones seems to be that you need public IP addresses, so they cannot do NAT traversal.

Ching is running the advanced ENUM trial in Taiwan, but they have troubles to get an official delegation because of the "delicate" situation between China and China.

Wednesday, February 16, 2005

Emergency Services 

Since I am also working now on Emergency Services for VoIP, I will also start to post issues related to Emergency Services here. The IETF has established a new workgroup "ecrit" -
Emergency Context Resolution with Internet Technologies.

NENA has defined three VoiP and E911 migratory stages:
I1 - deliver the 911call from VoIP
I2 - deliver via 911 network, with ANI and ALI within limits
I3 - deliver via IP-based E911 systems to IP PSAP

Since all I1 and I2 stages will be different in most countries depending on the existing local infrastructure, IETF WG ecrit will deal only with I3 related issues.

IETF WG ecrit will meet at the next 62nd IETF meeting in Minneapolis, currently four I-Ds are submitted:
in addition, the already existing inputs from Henning will be covered

The milestones of IETF WG ecrit are quite agressive, the most documents should be available in August 2005 (ok - lets be realistic - End of 2005).

In the meantime work on I2 seems to make some progress, as Jeff stated today on his blog:

Earlier today I received the following message:


I'm sure you are aware that a E911 VoIP trial is ongoing in King County
(greater Seattle area). The King County 911 office along with an ILEC,
Intrado, Vonage, and others have already completed 911 calls that route to
the correct Primary PSAP, carried the correct call back number, and the
correct address information. Dynamic routing (within one hour) of "changed"
address information when a user moves locations, is the last test and is
scheduled for next week (today the information takes a week to be updated
by industry). The method is unusual and still needs to be worked through
the standards organizations but proves that 911 issues for VoIP can be
resolved by cooperation between government and interested companies. If
approved by NENA and ATIS, this method of routing 911 calls will bring
better 911 service to VoIP users in all states.

The initial coordination of this continuing successful project was started
at the VON conference in Boston more than a year ago. Inviting staff from
the Washington State Utility Commission, as well as other state regulatory
commissions, allowed for the type of communication that will build
networks and resolve just these kinds of issues in the future between
industry and the regulatory world.

Hopefully the difficult issues like E-911 cost recovery will be resolved in
the same cooperative manner. Thanks again for making it possible for state
regulators to attend both the Boston and Santa Clara VONs. I will miss the
communication between attendees. I will also miss the excellent parties.


Bob Williamson
Senior Member Technical Staff
Washington Utilities and Transportation Commission
Olympia, WA.


Sunday, February 13, 2005

ERG Common Statement for VoIP regulatory approaches 

In my previous post I pointed to the European Regulators meeting last week.

As a result the ERG published a Common Statement on VoIP and its regulation.

This Common Statement contains:

-the ERG Common Statement on VoIP in general
-a specific statement for Numering and Number Portability
-a specific statement on access to emergency services

It also contains explanatory and background text and also two Annexes:

Summary of the Questionare on Numbering and Number Portability
Summary of the Emergency Services Questionare

This document will be very important for future of VoIP and IP communication in Europe and the harmonization of regulation. But especially the annexes show that there is still some work ahead.

I include the statements here, but I recommend to look at the document itself for further information:

The ERG Common Statement:

The ERG recognises that:

  • VoIP holds potentially significant benefits for the market and for the users.
  • The European regulatory framework provides the legal framework related to provision and use of VoIP in Europe today.
  • VoIP services exist today and are currently evolving. At this point no common conclusions on the evolution or revolution of the market posed by VoIP can be drawn. The market has not yet developed sufficiently.
  • A particular challenge is to apply existing regulations to services based on different technologies (e.g. circuit-switched vs. IP) in a technologically neutral manner. This is especially complicated when specific service features (like nomadic use) are linked specifically to a particular technology such as IP.

The ERG agrees that:

  • The regulatory approach to VoIP in Europe under the European regulatory framework[ for the benefit of consumers should enable the greatest possible level of innovation and competitive entry in the market, whilst ensuring that consumers are adequately protected.
  • Application and interpretation of rights and obligations in relation to VoIP should be in accordance with the European regulatory framework including the policy goals and regulatory principles existing today.
  • Legal analysis of the European regulatory framework in relation to VoIP by the ERG is more appropriate when the market has further developed.
  • The NRAs will further clarify the rights and obligations for VoIP providers.
  • The NRAs are committed to address barriers to market entry if they arise and in accordance with the European regulatory framework.
  • Consumers and service providers should be provided adequate information and be empowered to make informed choices about services and service provision.

ERG future work

  • The ERG will provide information and guidance on VoIP related issues in order to increase predictability in the market and the consistent application of the European regulatory framework across Europe for the benefit of consumers and service providers.
  • The ERG will continue to monitor and facilitate the development of the VoIP-market.
  • The future work will be addressed according to the IRG/ERG Work Program.

ERG Statement on Numbering and Number Portability:

  • In order to foster competition by stimulating the emergence of new services as well as promoting number portability numbering plans should be technologically neutral, based on the service descriptions and the same number ranges should in principle be available for both traditional voice and VoIP services.
  • Number portability is an important point from the consumer’s as well as the provider’s point of view while enabling end-users to retain their telephone number when changing a service provider. Number portability is one of the main enablers of competition.
  • Conditions concerning number portability should be equal for similar types of voice services within the scope of national numbering plans in order to facilitate consumer choice and promote effective competition.

ERG Statement on Emergency Services

  • Access to Emergency services is extremely important for citizens, irrespective of how a voice service may be classified for legal and regulatory purposes.
  • From a public policy point of view it is desirable that access to emergency services is available from as wide a range of electronic communications services as possible.
  • VoIP emergency calls from fixed or otherwise known locations should be routed to the nearest emergency centre on the basis of the contractually agreed physical address.[1]
  • When calling the emergency number, caller location information should be provided to the extent technically feasible.
  • In those cases where the caller location cannot be determined by the VoIP provider (most likely in the case of nomadic use of VoIP services), the end-user should be clearly and unambiguously informed by the VoIP provider about any restrictions in routing emergency calls and providing caller location information and the potential consequences.
  • Further requirements for nomadic VoIP services related to routing and caller location information should be discussed after technology and standards have matured.
  • Further requirements related to other types of VoIP services, SIP emergency calls, SMS emergency messages, email emergency messages, etc. should be discussed after technology and standards have matured.

[1] Note this is not relevant in countries where the first stage emergency operator answers all calls regardless of geographic location

Friday, February 11, 2005

EU regulators favour pro-competitive approach to Internet telephony 

The European Regulators met yesterday in Brussels and adopted a common statement to foster VoIP and regulate it with a light touch. The lagging behind related to the US and Asia, as
EU Information Society Commissioner Viviane Reding said in a statement, may have helped to come to this position. EU lags behind rest of the world - Japan has 4.9 million customers, while USA has about a million. Germany has 110,000, France about 220,000 and Britain has 50,000 VoIP users. Since the regulation in Asia is contrary to the US not with a light tough, one may ask how many VoIP users would be in Japan otherwise.

Anyway, the lights are switched to green in Europe for VoIP - in general, the devil may be in the details ;-)

Here is the complete press release:

“Voice over Internet Protocol has the potential to radically change the existing market structure”: this has been stressed today by the European Regulators Group (ERG), which brings together the 25 national regulatory authorities responsible for electronic communication markets. Meeting in Brussels, the ERG adopted a common statement on Voice over Internet Protocol (VoIP) services in order to facilitate the roll out and widespread use of Internet telephony in Europe. The European Commission itself favours an EU-wide “light touch” approach to Internet telephony as the best way to encourage competition between internet carriers of telephone traffic and traditional telephone networks.

“I intend to strongly promote an open, pro-competitive approach to Voice over IP in all 25 Member States of the European Union, and I therefore welcome today’s first positive joint signal from the national regulators”, said Commissioner Viviane Reding, responsible for Information Society and Media. “I expect Voice over IP to lead to more diverse and innovative services in the market which may well have an even bigger impact on consumers and businesses than email. And Voice over IP is just the tip of the iceberg. IP-based networks and services will be the basis for a whole new range of communications services, not only benefiting consumers directly, but feeding through directly to the whole economy. I am convinced that, as the market develops, the European Commission and national regulators will jointly ensure that throughout the EU, the roll-out of new IP-based services will not be hindered by regulatory hurdles.”

Until recently, VoIP was essentially a niche phenomenon (similarly to email and the internet a decade ago), but it now has hit the mainstream consumer and business markets. As IP technology becomes a widespread phenomenon, today’s telephone networks will be completely restructured, making the EU’s electronic communications infrastructure more flexible and cost-efficient.

The Commission conducted a public consultation on VoIP in June 2004, which sought to clarify the regulatory issues related to VoIP services. Commissioner Reding and her services will build on the results of this consultation in the months to come and closely work together with national regulators to ensure that Internet telephony will be able to unfold its considerable potential for enhancing innovation and competitive market entry in the electronic communications sector.

Thursday, February 10, 2005

SIPconnect , direct IP peering and what is missing 

The SIPconnect Interface Specification launched by Cbeyond Communications in 2004 with support from Avaya, BroadSoft, Centrepoint Technologies, Cisco Systems, and Mitel is a standards-based method of interconnection between IP PBXs and VoIP service provider networks. It specifies a reference architecture, required protocols and features, and implementation rules necessary for seamless peering between IP PBXs and VoIP service providers.

Of course this is a good start to provide IP-based connectivity, but the scope of the architecture is quite limited, namely to the IP-based User-Network-Interface (UNI) between an IP PBX and a VoIP service provider. The achitecture consists of the IP PBX, the Call Control Server (CCS) and the Media Server (MS) of the VoIP Service provider, and a Trunking Gateway (TGW) to the PSTN. So basically a company running an IP PBX may only interface with a VoIP service provider saving the own gateway to the PSTN. All calls out of the IP PBX are routed via the VoIP service provider.

There is an additional element, but only optional (Henry ;-) - the unfamous Session Border Controller (SBC).

What is missing are two major points:

1. How VoIP service providers interconnect (the Network-Network-Interface NNI) and the routing mechanisms to achieve this (e.g. carrier/infrastucture ENUM). But this may be any issue for VoIP service provides only. The SIP Forum Service Providers Working Group is currently looking after these issues.

2. and even more important, the answer to the question why IP PBX need VoIP service providers to peer with each other on the Internet.

At the SIPconnect home page in the FAQ section it is stated under the topic:

How does SIPconnect benefit business users?

Business customers are the end users who will ultimately benefit from direct IP peering.

Businesses that take advantage of SIPconnect where their IP PBX peers directly with their communications service provider eliminate the need for expensive TDM gateways, and increase the efficiency with which they use local access facilities. They also increase their opportunity to purchase enhanced applications from service providers and can more easily extend the functionality of their IP PBX across service provider networks.

I personally understand the term "direct IP peering" in such a way that IP PBX connected to the Internet are peering directly with each other and not with and via VoIP services providers.

The best and simplest way to achieve this is the usage of ENUM to peer directly between IP PBX. This requires only the addition of an ENUM client into the PBX Software and the reachability of the IP PBX via a public SIP URI. Examples are the open source Asterisk and the SIP Express Router (SER) from An animated example scenario is contained in my presentation (slide 10) given at the Domain Pulse event.

This does not prevent IP PBX to use either their own gateways to the PSTN or the IP-based peering as defined by SIPconnect if a E.164 number is not found in ENUM.

The approach is basically the following:

1. An IP PBX is first querying ENUM for the number dialled. If an entry is found in ENUM, the other party (other IP PBX or residential user) is contacted directly.

2. If no entry is found, the call is forwarded to the VoIP service provider.

3. The VoIP service provider first tries to find another VoIP service provder hosting the number dialled, e.g. by querying Infrastructure ENUM. Only of this also fails, the call is routed via the PSTN.

The basic idea is to keep the call on IP for all end-points that can be reached on IP, not only for saving money, but even more important to improve QoS and enable all additional features possible with SIP-SIP communication.

Saturday, February 05, 2005

Domain Pulse 

As already mentioned I partizipated the last two days at Domain Pulse, the forum of DENICde, and

Most of the presentations given may be now downloaded via here.

The first day was mainly dealing with political issues, starting with an Introduction to ICANN, two keynotes, one from the Austrian State Secretary in the BMVIT and from the Austrian Regulator, continued with the history of the at. domain and then Harald Alvestrand explained How to make an RFC- Mechanisms and Background. The basic message was simple: you have to write a draft, talk much and then, most important, you have to WAIT... - How true. He did not explain to much about the background.

In the afternoon fun the topics were serious again: ICANN - WSIS - How much governance and regulation does the Internet need ? and Future vision from a busuness point of you.

The evening ended as usual in Vienna with a visit to a Heurigen in Gumpoldskirchen.

The second day started easy with a short Intro to ENUM by myself and Robert Schischka giving a short demo of how to use ENUM and modify an entry via

Then Robert Schischka, Sabine Dolderer and Marcel Parodi gave regional status reports regarding ENUM in Austria, Germany and Switzerland and I gave a short overview of the rest of the world.

Now the heavy technical stuff started with two execellent presentations, bringing the highlight of the day
  • DNSSec - Basics, Risks and Benefits by Olaf Kolkmann, RIPE NCC (PPT) and
  • IPv6 - International approach Hans-Peter Dittler, (PPT).
After this heavy stuff Bart Mackey from Verisign ended the morning with Business and Operational Challenges of Rapid Growth: Lessons Learned in .COM/.NET (PPT) giving some interesting figures.

After lunch the organizers had the excellent idea to invite Kabaret-Star Dolores Schmidinger to give a somewhat different point of view related to the Internet.

The day ended with the unavoidable discussion on SPAM.

I can only congratulate the crew from to this excellent and well organized event.

Tuesday, February 01, 2005

Skype - All together, now! 

Skype - All together, now! Posted by Hello

Talking to the Dead or One Foot Under 

I just detected a new business case for VoIP. Some people think that there are 11 Techniques to Talk to the Dead, but a German entrepreneur launched a twelfth one - TelefonEngel, and patented it already in many countries.

Since the site is German, what he is offering is basically a mobile phone with a HUGE battery and a hands-free set a bereaved buries into the grave and now she can call (for approx. 12 month) and talk to the dear deceased one (or at least nag him). Since the called party may not be able or does not want to go off-hook, the phone is configured to auto-answer. Push-to-talk could even be better.

It is recommended by the company to bury the unit the size of a shoebox at least 1 feet under not to disturb conventional talkers at the grave and not to scare the living daylight out of innocent passers-by.

This could be a new business case for our wireline telcos to provide each grave with an always-on broadband Internet connection, an IP-phone, an e-mail and IM address, a webpage and finally a blog. Presence seems not to be an issue.

ENUM in Financial Times Deutschland 

The Financial Times Deutschland (FTD) had an article yesterday on ENUM - Magic Phonebook - (sorry, german only).

Of course an article in FT is important for ENUM and at least the first use case is a valid one - namely linking VoIP islands (companies) together. But as already the title suggests, the other use case leadsimmediately to the privacy problem.

As second use case a follow-me service is described, which would be nice if implemented with SIP forwarding and presence, but NOT in ENUM.

ENUM is not a real-time forwarding service and it is also not a presence service.

James Seng on IP Telephony in Asia 

James Seng has quite an extensive analysis on the sitution of IP Telephony in Asia.

Well, the first and foremost problem is the lack of harmonization of regulatory framework across Asia.

...., you need to educate the regulators and fight the incumbent rejecting you at the same time (and repeat that for each economy).

Interesting statements from a regulator ;-)

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