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Abstract
The remarkable growth of the Internet draws the attention of de jure and de facto standardization organizations which used to have few activities on IP technology. This article provides the new trends in standards/specifications of such organizations -- including ITU-T, ATM-F, DAVIC, TIPHON, and others -- on IP-related technologies. These organizations primarily focus on IP and telecommunication integration. IP technology itself is still the main focus of IETF. The harmonized approach of these organizations is indispensable.

 

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Standards Topics

IP and Telecommunication Integration: De Jure and De Facto Standards Have Entered a New Era

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Koichi Asatani
Kogakuin University

 

Since 1995 the numbers of Internet hosts and users have been growing very dramatically. Recently, Internet applications have been enhanced to support real-time applications (circuit emulation) such as IP telephony. Internet Protocol (IP) related standards/specifications are being developed primarily by the Internet Engineering Task Force (IETF). Some IP-related standards/specifications are also being developed by other fora and consortia such as the ATM Forum (for IP over asynchronous tranfer mode) and the Digital Audio Visual Council (DAVIC). IP applications such as IP telephony and IP fax may require interworking with similar telecom applications. Meanwhile, the International Telecommunication Union -- Telecommunication Standardization Sector (ITU-T), developing global standards on telecommunications, has started to review IP-related activities with a view to accelerating the standards on IP-related technology from the viewpoint of interworking between telecom and IP networks and applications.
This article first describes the outlines of IP-related organizations, including fora/consortia and European Telecommunications Standards Institute (ETSI) project TIPHON, which are developing IP-related standards/specifications, by introducing their main work areas and working methods. Regarding IP telephony, ETSI project TIPHON is playing a central role, collaborating with IETF, ITU-T, and other organizations. It then reviews the IP-related activities in ITU-T, and outlines the standards/specifications of these organizations related to telecom and IP internetworking and application interworking, including ITU-T Recommendations. It also describes the collaborative relationship among these organizations.

IP-Related Organizations

ISOC/IETF

The Internet Society (ISOC) was established in 1992. The ISOC is the leading organization in IP areas, and covers all aspects of the Internet, including Internet standards/specifications development and their administration and operation.
The Internet Architecture Board (IAB) provides guidelines and policies on Internet architecture and protocols as a Board of ISOC, which was established in 1989.
The IETF develops IP standards and specifications following the guidelines given by IAB. The IETF initiated IP specification development in 1986 and has published more than 2500 requests for comments (RFCs) so far. One of the distinctive characteristics of IETF is its openness and rough consensus. Anyone can participate in IETF meetings and submit documents. The IETF has more than 110 active Working Groups in eight areas: Applications, General, Internet, Operations and Management, Routing, Security, Transport, and User Services. Each Working Group produces Internet drafts primarily based on e-mail-based discussion. These drafts become RFCs after they get rough consensus (no voting).
The Internet Engineering Steering Group (IESG) is an experts group that manages the standard track. The IAB appoints members of IESG.
The standard track is a procedure of getting Internet standard status for RFCs. Internet drafts expire six months after they are published. The protocols produced by relevant WGs based on the Internet drafts are submitted to IESG to move to RFC status, which is the initiation of the standard track. The RFCs cover all areas including protocol specifications, addressing and naming management, administrative information, FAQs and references, and experimental evaluation of systems.
The RFCs on protocols follow the standard track. The standard track does not apply to informational, experimental, and historical RFCs. Historical RFCs are those that have been replaced by the revised or new versions of RFCs that are in current use.
The RFCs move toward "standard (S)" through "proposed standard (PS)," and "draft standard (DS)" statuses. RFCs with PS status get DS status after six months when they become PS and with the approval of IESG. RFCs with DS status get S status after four months when they become DS and with the approval of IESG. RFCs with S status have standard (STD) numbers assigned by IESG. Standards should be implemented by at least two independent organizations, associated with security and network management descriptions. Currently, there are approximately 50 RFCs with S status.
Some RFCs become historical when they are replaced by alternative or newer RFCs.

The ATM Forum

The ATM Forum was established in 1991 in order to provide implementation standards for ATM applications, primarily in private networks. The original intention was to promote ATM implementation by computer vendors. The enhanced work areas cover IP-related issues such as IP over ATM and Multiprotocol over ATM (MPOA). The specification development is carried out under the following Working Groups (WGs):
B-ICI (Broadband Intercarrier Interface)
Control Signaling
Data Exchange Interface
LAN Emulation/MPOA
Network Management
Physical Layer
P-NNI (Private Network to Network Interface)
Residential Broadband
Service Aspects and Applications
Security
Signaling
Testing
Traffic Management
Voice and Telephony over ATM
User–Network Interface

DAVIC

DAVIC was established in 1994, aimed at system and applications development based on MPEG-2. MPEG-2 coding was jointly developed by International Organization for Standardization/International Electrotechnical Commission (ISO/IEC)Joint Technical Committee 1 (JTC1) TC29 and ITU-T Study Group 15 (SG15). DAVIC specifications primarily consist of available standards/specifications that are developed by other organizations such as ITU-T, ISO/IEC JTC1, and IETF. In other words, DAVIC specifications are also implementation standards. If there are no available standards/specifications, DAVIC will prepare an original specification for its purpose.
Three WGs are developing DAVIC specifications on application requirements, system design and integration, content presentation, API, and security.

TIPHON

Telecommunications and Internet Protocol Harmonization Over Networks (TIPHON) is one of the projects under ETSI. Seven WGs are developing specifications related to IP telephony:
WG1: Requirements
WG2: Architecture
WG3: Signaling/Call Control
WG4: Numbering/Naming/Addressing
WG5: QoS
WG6: Verification
WG7: Wireless and Mobility
WG6: conducts verification tests of ETSI specifications by using a testbed
ETSI publishes several types of deliverables: Europe-Norm (EN), ETSI Standard (ETS), ETSI Report (ETR), Technical Specification (TS), and Technical Report (TR).
All deliverables of TIPHON are TSs or TRs, which are approved by the project agreements. ETSs and ETRs require a national voting process, which takes a longer time than project agreements. One of the requirements of these activities is timeliness. TS and TR documents are appropriate for this purpose. Project agreements are made based on majority consensus. All TS and TR documents have been approved unanimously, and no voting has been conducted so far.

The Multimedia Switching Forum

The Multimedia Switching Forum (MSF) was founded in November 1998. The main work area is to provide implementation standards for a multiservice switch (MSS) based on the ATM platform supporting every type of service, including IP services and ATM services as well as the existing telecommunication services. The specifications are produced by three WG; Architecture (interface structures and interface principles), Switch Control (control and management interfaces of the switch), and Media (voice control model and media gateway interfaces).

The Optical Internetworking Forum

Recent developments in wavelength-division multiplexing (WDM), Gigabit Ethernet, and gigabit/terabit switches and routers enable simpler, more scalable high-performance and low-cost networks. The Optical Internetworking Forum (OIF) was founded in April 1998. The main objective of the OIF is to develop specifications for optical internetworking under such new environments of high-speed technologies. The first target is to develop specifications on IP over WDM or IP over an optical network, which was dealt with by no standardization organizations when it started. ITU-T started IP-related studies, and covers these aspects in ITU-T SG15.

IP-Related Activities in ITU-T

ITU-T started to study the global information infrastructure in 1995, with the leadership of SG13 as an ITU-T project [1, 2]. At the SG13 meeting in February 1997, IP-related issues were discussed as part of the GII project. The main task was to coordinate the studies on relevant IP areas being done by relevant SGs, including SG13.
At the ITU-T SG Chairs meeting in May 1997, IP-related issues were recognized as one of the key subjects in ITU-T. Based on this consensus, an IP-related project was founded under the umbrella of the GII project led by SG13. The GII evolution and its relationship with IP are described in the Y.100 series of Recommendations [3–5].
In June 1998, SG13 agreed to put more focus on the issues related to cross-sectional areas of IP and telecom networks and applications. The Telecommunication Standardization Advisory Group (TSAG) agreed to study IP-related issues with SG13 as lead SG and to establish a formal liaison with ISOC/IETF.
The ITU Plenipotentiary Conference in October 1998 passed the resolution that ITU as a whole should take an initiative role in studying and promoting IP and telecom interoperability. It was also resolved that ITU-T should play a leading role in developing IP-related standards.
In December 1998, SG13 hosted the ITU-T Workshop on IP and Telecom Related Issues in Orlando. Key players were invited to the Workshop from major organizations such as IETF, ATM Forum, ETSI TIPHON, and DAVIC, including relevant SGs of ITU-T. The objectives of the workshop were:
  • To establish a formal collaborative relationship between ITU-T and IETF
  • To review the study status in each relevant organization and to clarify the areas and issues which should be covered by ITU-T
  • To identify necessary standards (Recommendations), their appropriate timing, and responsible SGs/organizations
At the SG 13 meeting of February 1999 it was agreed that the IP project is of highest priority, and an IP project manager was assigned to coordinate all IP-related activities within ITU-T and liaisons with IETF.
SG13 also started to develop New Questions for the next study period of 2001–2004 focusing on IP-related issues. In order to accelerate IP related studies, the first IP Experts Meeting will be held in September 1999. It is based on the existing Questions of SG 13, which are implicitly or explicitly related to IP technology. Other SG experts are also expected to join the meeting for the integrated IP-related studies.

Collaboration among ITU-T, IETF, and Other Fora/Consortia

The ITU-T has guidelines for collaboration with fora and consortia, such as stability of specifications and openness. TSAG investigates the candidate organizations' conditions for approval. IETF, ATM-F, and DAVIC are formally recognized as organizations for collaboration. ETSI, however, is a regional standardization organization, and the agreements of ETSI are submitted as contributions to ITU-T through ETSI members. The MSF and OIF are not included as organizations for collaboration at the moment.
TSAG decided to have a collaborative relationship with IETF in September 1998. ITU-T started to review the relationship between ITU-T SGs' Questions and IETF WGs in the IP project of SG 13. DAVIC has a collaborative relationship with SG9 in general, with SG16 on protocols, and with SG13 on architecture. DAVIC specifications have many references and citations from ITU-T Recommendations and IETF RFCs, in order to avoid duplication of work areas.
The ATM Forum has general liaisons with ITU-T SG13 regarding almost all aspects of ATM, including IP over ATM. The IETF also has activities on IP over ATM.
The TIPHON specifications only refer to the specifications and standards of other organizations if they are available, to avoid duplication of work areas. The TIPHON has a close relationship with ITU-T SG2 for global country code allocation to IP telephony, SG16 for protocols such as H.323v2, and SG11 for SS7 signaling. The study of general architecture for IP telephony will require the collaboration with ITU-T SG 13. The TIPHON also has liaisons with IETF and ANSI T1 by sending/receiving liaisons or submitting documents, as shown in Fig. 1.
So far, MSF has no formal liaisons with other organizations, since it was established in November 1998. The main objectives of MSF will require collaborations with ITU-T, ATM-F, and IETF.

IP-Related Standards and Specifications

Historically, IETF has been the center of IP specifications. According to the enhancement of IP capabilities, specifications and standards related to IP are developed by other organizations such as ITU-T, ETSI, ATM-F, and DAVIC.

IETF

The RFCs on protocols fall into three categories:
  • IP specifications, such as RFC794 on IPv4 and RFC1883 on IPv6
  • Transport layer specifications, such as RFC 793 on TCP specification and RFC768 on UDP specification
  • Application specifications such as IP over ATM, such as RFC1557 on classical IP over ATM and RFC 2332 on Next Hop Resolution Protocol (NHRP)
Current hot topics are multiprotocol label switching (MPLS), voice over IP, and IP fax. Major RFCs are listed in Table 1, related to interworking between telecom and IP networks and applications.

ATM Forum Specifications

The ATM Forum deals with the cross-section of IP and ATM issues, such as IP over ATM, LAN emulation (LANE), and MPOA. Support of best effort type of service is studied under multiple grades of services (multi-GoSs). The GoS is classified by bandwidth and delay. The guaranteed frame rate (GFR) service category is also studied to support IP transport. MPOA 1.0 uses ATM as a backbone for the Internet. Quality of service (QoS) routing is the major issue of MPOA 2.0. ATM specifications related to IP are listed in Table 2.

DAVIC

A key element of DAVIC specifications is the set-top box (STB). DAVIC specification 1.0 defines the platform model and specification tools. It was followed by DAVIC 1.1 and DAVIC 1.2, defining applications on top of the platform defined in DAVIC 1.0.
DAVIC initially focused on video on demand and karaoke on demand (1.0), and moved to enhanced broadcast with Internet access (1.1, 1.2, and 1.3) and high-quality intranets with local storage and push technology based on IP technologies in 1998 (1.4).
DAVIC 1.5, to be completed in 1999, addresses "TV anytime," access to content using integrated home storage, "TV anywhere," real-time access to remote content via the Internet, and "DAVIC Intranet," a high-quality well-dimensioned IP-based network that can easily be interconnected to create a worldwide network with managed end-to-end QoS.
DAVIC's current priority is to promote the evolution of residential digital networks and systems for IP-based information delivery plus local storage for ubiquitous (including mobile and portable numbering), quality-managed, one-to-one services, including home creation of content (1999).
Table 3 outlines the DAVIC specifications.

TIPHON

TIPHON is dedicated to IP telephony. Its specifications cover requirements for service interoperability, global architecture (interfaces and functions including gatekeeper functions), call control procedures, information flows and protocols, end-to-end QoS parameters (including customer premises networks), address translation between E.164 and IP, technical aspects of billing and accounting and reconciliation, security profiles and procedures, and validation for interopeablity. The studies are carried out according to the following scenarios. Scenario 1: IP to SCN, from an originating H.323 on IP network to a receiving terminal on switched circuit network (SCN) such as PSTN/ISDN/GSM (completed)
  • Scenario 2: SCN to IP, from an originating SCN terminal to an H.323 terminal (to be completed in 1999)
  • Scenario 3: SCN to IP to SCN, where two SCN terminals communicate through an IP network as a trunk (to be completed by the end of 1999)
  • Scenario 4: IP to SCN to IP, where two IP terminals communicate through SCN as a trunk (to be completed by the end of 1999)
In replying to requests from TIPHON, ITU-T SG 2 assigned a country code/service code for IP telephony with 12 digits in Recommendation E.164. E.164-IP mapping specifies two-stage lookup, mapping from E.164 number to IP address of the home gatekeeper and mapping from E.164 number to IP address of the end user in the small table of the home gatekeeper. These specifications are validated on the testbed called TIPHON net. The current hot topics are IP and SS7 signaling interworking, security profiles, gateway functional decomposition, intergatekeeper and interdomain communications, QoS signaling, terminal/user roaming and mobility, and service mobility.
Table 4 summarizes the available TIPHON specifications.

MSF Specifications

Table 5 shows the MSF specifications.

ITU-T Recommendations

ITU-T has been carrying out work on the issues related to telecom and IP networks under the relevant Questions of relevant SGs. ITU-T started to enhance IP-related studies in a coordinated way. The ITU-T IP project has 12 areas, as follows:
Area 1 -- Integrated architecture
Area 2 -- Impact to telecommunications access infrastructures of access to IP applications
Area 3 -- Interworking between IP-based networks and switched-circuit networks, including wireless-based networks
Area 4 -- Multimedia applications over IP
Area 5 -- Numbering and addressing
Area 6 -- Transport for IP-structured signals
Area 7 -- Signaling support, IN, and routing for services on IP-based networks
Area 8 -- Performance
Area 9 -- Integrated management of telecom and IP-based networks
Area 10 -- Security aspects
Area 11 -- Network capabilities including requirements for resource management
Area 12 -- Operations and maintenance (OAM) for IP
Work areas of ITU-T IP projects and relevant ITU-T SGs are schematically illustrated in Fig. 2. Table 6 shows the major Draft new and revised Recommendations' target timing and related IETF WGs for Areas 1–4. This table is based on the IP project report [6], supplemented and updated by the author. The survey is not yet complete, and further work is necessary to complete the list, including further analysis to identify potential areas of IETF where ITU-T could collaborate. Furthermore, this table is not exhaustive and is to be further updated according to the progress of ongoing work done by relevant ITU-T SGs and IETF WGs.

Conclusion

The Internet has been growing very rapidly with several tens of percentage annual growth recently. The number of host computers is estimated to be 40 million as of the end of 1998. Telecommunications, computer, broadcasting, and consumer electronics, including contents creation, are going to support IP applications based on their platforms. ITU-T has initiated studies on IP technology more systematically and more seriously, taking into account the current trends in IP technology and markets. More and more fora and consortia are being established in the standards arena, and more and more are becoming involved in IP-related technologies. It is very hard to take in the total picture on IP standards/specifications. This article is the first attempt to catch the very recent trends in telecommunication and IP integration standards/specifications.
This area requires quick response to market demands. One of the big differences in procedures between de jure standardization organizations and fora/consortia is speed. For example, ITU-T adopts unanimous consensus, while most fora and consortia use majority consensus or even rough consensus. Telecommunications and IP are each a very wide area, and their integration will open wider applications and require more collaboration. Harmonization of general directions and working methods are key issues for this new trend.

Acknowledgments

The author would like to sincere thank to Mr. Helmut Schink, Chair of TIPHON, for providing the information on TIPHON.

References
[1] K. Asatani, "Telecommunications Standardization for Global Information Infrastructure," Encyclopedia of Telecommunications, Marcel Dekker, 1998.
[2] K. Asatani et al., Feature Topic on Standardization for GII and Multimedia Communications, IEEE Commun. Mag., vol. 36, no. 9, Sept. 1998.
[3] ITU-T Rec. Y.100, "GII Overview," 1998.
[4] ITU-T Rec. Y.110, "GII Principles and Framework Architecture," 1998.
[5] ITU-T Rec. Y.120, "GII Scenario Methodology," 1998.
[6] ITU-T SG13, "IP Project Description -- Version 0.4," TD56, Geneva, Switzerland, 15–26, Feb. 1999.

Related Web Sites
ITU-T
IETF
ATM Forum
DAVIC
TIPHON
MSF
OIF

Biography
Koichi Asatani received his B.E.E.E., M.E.E.E., and Ph.D. degrees from Kyoto University in 1969, 1971, and 1974, respectively. From 1974 to 1997 he was engaged in R&D on optical fiber communication systems, high-definition video transmission systems, optical fiber subscriber loops, ISDN, B-ISDN, ATM networks, and their strategic planning. Currently he is professor, Information Communication Networks Laboratory, Department of Electronic Engineering, Kogakuin University, and professor, Waseda University. He has published more than 30 papers in these areas. He is co-author of the books Optical Communications (Shoko-do Publishing., in Japanese), Introduction to B-ISDN (Ohm-sha Publishing., in Japanese), Designs of Telecommunication Networks (IEICE, in Japanese), Introduction to ATM Networks and B-ISDN (John Wiley and Sons, 1997), Multimedia Communications Networks: Technologies and Services (Artech House, 1998), Encyclopedia of Telecommunications (Marcel Dekker, 1998), and others. He is Vice-Chair of ITU-T SG 13 (formerly CCITT SG XVIII) since 1988, and Chair-Elect of IEEE Technical Committee on Communication Quality and Reliability (CQR-TC), Ex-Chair of the IEICE Technical Committee on Communication Quality (CQ-TC), Feature Editor on Standards of IEEE Communications Magazine, and Chair of the Ninth Special Committee of the Telecommunication Technology Council.