Network Working Group HF Zhu INTERNET-DRAFT UTAustin Expire in six months October, 1997 DNS and URL Level Addressing for Public Circuit-Switching Network Devices Status of this Memo This document is an Internet Draft. Internet Drafts are working documents of the Internet Engineering Task Force (IETF), its Areas, and its Working Groups. Note that other groups may also distribute working documents as Internet Drafts. Internet Drafts are draft documents valid for a maximum of six months. Internet Drafts may be updated, replaced, or obsoleted by other documents at any time. It is not appropriate to use Internet Drafts as reference material or to cite them other than as a ``working draft'' or ``work in progress.'' Please check the I-D abstract listing contained in each Internet Draft directory to learn the current status of this or any other Internet Draft. Abstract Recently there are a number of efforts [sw1, sw2, in,tpc, etc.] of trying to connect the packet-switching network with circuit-switching network, especially connecting the Internet with public telephone networks. The first problem of such interconnection is naming and addressing, later will come with directory services and routing problems. This draft concentrates on naming for DNS and URL. Other problems are discussed in other documents [utrpt, framework]. 1. Requirements Requirements are as specified in [RFC2119]. 2. DNS and URL Naming 2.1 Introduction New Internet top domains for naming devices of public circuit switching networks are proposed here. For example: for a telephone number 471-1234 in Austin (area code 512) in US (country code +1), we use 4711234.512.1.tel as its name, or even more advanced like this: 4711234.austin.us.tel, which is not always one-to-one mapping. To reach an extension, one or many "p" as defined in [urltel1] which stands for pausing one or more second after dialing the number can be used. For instance, 234pp4711234.512.1.tel stands for dialing +1-512-4711234 and wait for two seconds (two "p") and connect to extension 234. A dot can also be added between the phone number and the extension number such as 234.pp.3711234.512.1.tel. For fax, the top domain of .fax is proposed to use. The name for a fax number of 471-5555 in Austin of US can be 4715555.512.1.fax, or 4715555.austin.us.fax, which is actually the same port for 4175555.512.1.tel. Since the mapping of DNS to IP is many-to-many, this scheme is valid with current DNS conventions. Similar rules can be applied to other devices, such as xxx.isdn, etc.. HF Zhu [Page 1] Internet-Draft DNS and URL Addressing for PTSN Oct, 1997 URL can be achieved via the above DNS naming. For example: SIP://4711234.512.1.tel . This naming can also facilitate the voice mail or fax_via_email, for example: someone@4711234.512.1.tel . 2.2 Formal Syntax Name := [ extension 1* extsymbol ] local_number "." area "." country "." device_domain device_domain := "tel" | "fax" | .... etc. country := country_code | country_domainname area := area_code | area_name local_number := 1*phonedigit extension := 1*phonedigit phonedigit := dtmf_digit | digit digit := "0" | "1" | "2" | "3" | "4" | "5" | "6" | "7" | "8" | "9" dtmf-digit := "*" | "#" | "A" | "B" | "C" | "D" extsymbol := "p" | others .. ? Note: can be further refined or enhanced with some other functions. 3. Address Lookup The SRV DNS [rfc2052] can be used to support looking for a server on which a new protocol is running to provide information on interconnection services or even general integration services. We call these servers "Interconnection Information Server", or "Integration Information Server" (or Info. Server, in short). The information include the "connection points" (can be a Web server or gateway/router) between Internet and Public Telephone Switching Network, together with the information about services on those points (e.g. service types, price, local QoS, etc.). Actually the SRV DNS is just one of the five methods used in SIP (Session Initiation Protocol) [sip] to look up a server. All these five methods can be used to look up Info Servers. It is easy to deploy these DNS services as the domains we use here are new domains. A list of Info servers for the same domain are available for fault-tolerance (such as primary, secondary, etc.). They provide a list of connection points to the PTSN (or even general public circuit switching networks offerred by some connection providers for a specific tel/fax number or a group of tel/fax numbers. The list should also contain some neccessary information such as the price and services, etc.. These connection points can be many forms, such as Web servers, or high-performance gateways/routers to facilitate large traffic. The query between a host and a Info Server can be done by a simple protocol, or appropriate existing directory service protocols. The NIC of each level under .tel and .fax domain must be responsible for the correctness of the information stored in these Info Servers. HF Zhu [Page 2] Internet-Draft DNS and URL Addressing for PTSN Oct,1997 The protocol should be as simple as possible to improve performance (when using dynamic connection points decision and routing, refer to [2]). It can be designed based on TCP and UDP, like SIP. The protocol should also provide a mechanism to exchange information among them and keep them consistent. Therefore, an extension of SIP may be used for the above purpose. This should be discussed in the MMUSIC Working Group of IETF to see if it is needed to design a new protocol. Other directory services on the Internet such as LDAP [ldap], or those directory services discussed in the IDS (Integrated Directory Service) WG of IETF. However, basically, over-complicated directory services are not necessary and may add burden to the client and reduce the performance. 4. Security Consideration Security is important to ensure the Info Server store the correct information for each connection providers. 5. Author's Address Haifeng Zhu Electrical & Computer Engineering Department The University of Texas at Austin Austin, TX 78712-1084 USA Email: zhf@ece.utexas.edu Tel: +1-512-475-6875 Fax: +1-512-232-1739 6. References Some of the authors names will be added as soon as I find them. Sorry. [utrpt] Haifeng Zhu, "Interconnecting Internet and Public Circuit-Switching Networks: Architecture and Technology", Research Report CS97395T, The University of Texas at Austin, 1997 [framework] Haifeng Zhu, "Framework for Interconnecting Internet and Public Circuit-Switching Network", Internet-Draft, "Work in progress", 1997 [urltel1] A. Vaha-Sipila, URLs for Telephony, draft-antti-telephony-url-01.txt, Sep. 19, 1997 [sip] MMUSIC WG of IETF, Handley, Schulzrinne, Schooler, SIP: Session Initiation Protocol, draft-ietf-mmusic-sdp-04.ps, 2nd Sept, 1997 [sw1] I. Faynberg, M. Krishnaswamy, H. Lu, A Proposal for Internet and Public Switched Telephone Networks Internetworking, draft-faynberg- telephone-sw-net-00.txt, March, 1997 [sw2] M. Krishnaswamy, H. Lu, Information Exchange to Be Supported by the Service Suppport Transfer Protocol (SSTP), draft-krishna-telephone-sw- net-00.txt [in] L. Conroy, M. Lautenbacher, R. Scholl, Analysis of Services and Interfaces used when Interworking Between the Internet and the Intelligent Network (I.N.), draft-conroy-interfaces-in-net-00.txt [h323] International Telecommunication Union, Packet Based Multimedia Communi- cations Systems, ITU-T H.323 [rfc2119] S. Bradner, Key words for use in RFCs to Indicate Requirement Levels, RFC 2119, March, 1997 HF Zhu [Page 3] Internet-Draft DNS and URL Addressing for PTSN Oct, 1997 [tpc] RFC 1530-1569, RFC 1703, TPC.INT experiments [qosroute] Eric Crawley, Raj Nair, Bala Rajagopalan, Hal Sandick, "A Framework for QoS-based Routing in the Internet", draft-ietf-qosr-framework-01.txt [ldap] RFC 1777, RFC 1778, and a draft version 3 proposal. HF Zhu [Page 4]