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diff --git a/doc/rfc/rfc3508.txt b/doc/rfc/rfc3508.txt new file mode 100644 index 0000000..c493c98 --- /dev/null +++ b/doc/rfc/rfc3508.txt @@ -0,0 +1,339 @@ + + + + + + +Network Working Group O. Levin +Request for Comments: 3508 RADVISION +Category: Informational April 2003 + + + H.323 Uniform Resource Locator (URL) Scheme Registration + +Status of this Memo + + This memo provides information for the Internet community. It does + not specify an Internet standard of any kind. Distribution of this + memo is unlimited. + +Copyright Notice + + Copyright (C) The Internet Society (2003). All Rights Reserved. + +Abstract + + ITU-T Recommendation H.323 version 4 introduced an H.323-specific + Uniform Resource Locator (URL). This document reproduces the H323- + URL definition found in H.323, and is published as an RFC for ease of + access and registration with the Internet Assigned Numbers Authority + (IANA). + +Conventions used in this document + + The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", + "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this + document are to be interpreted as described in BCP 14, RFC 2119 [2]. + +Table of Contents + + 1. Introduction...................................................2 + 2. URL Scheme Formal Syntax Definition and Character Encoding.....2 + 3. Intended Usage.................................................3 + 4. Applications and/or protocols, which may use H.323 URL scheme..3 + 5. Security Considerations........................................3 + 6. IANA Considerations............................................4 + References........................................................4 + Acknowledgments...................................................5 + Author's Address..................................................5 + Full Copyright Statement..........................................6 + + + + + + + + +Levin Informational [Page 1] + +RFC 3508 H.323 URL Scheme April 2003 + + +1. Introduction + + ITU-T Recommendations H.323 [3] and H.225.0 [4] define a system for + multimedia communications services over packet based networks. + H.225.0 [4] defines an alias type for carrying any standard Uniform + Resource Locator (URL). H.323 version 4 [3] introduced an H.323- + specific URL, which may be used to resolve the address of a network + entity to which H.323 calls may be directed. + + This document reproduces the H323-URL definition found in ITU-T + recommendation H.323 [3] and is published as an RFC for ease of + access and IANA registration. + +2. URL Scheme Formal Syntax Definition and Character Encoding + + The H.323 URL is defined in ABNF as shown below. Note that it + utilizes the Core Rules specified in section 6.1 of [2]. + + H323-URL = "h323:" address [ url-parameters ] + address = user / "@" hostport / user "@" hostport + user = 1*(%x21-24 / %x26-3F / %x41-7F / escaped) + ; The symbols "%", "@", and symbols with + ; a character value below 0x21 may be + ; represented as escaped sequences. + hostport = host [ ":" port] + host = hostname / IPv4address / IPv6reference + hostname = *( domainlabel "." ) toplabel [ "." ] + domainlabel = alphanum / alphanum *( alphanum / "-" ) alphanum + toplabel = ALPHA / ALPHA *( alphanum / "-" ) alphanum + IPv4address = 1*3DIGIT "." 1*3DIGIT "." 1*3DIGIT "." 1*3DIGIT + IPv6reference = "[" IPv6address "]" + IPV6address = hexpart [ ":" IPv4address ] + hexpart = hexseq / hexseq "::" [ hexseq ] / "::" [ hexseq ] + hexseq = hex4 *( ":" hex4 ) + hex4 = 1*4HEXDIG + port = 1*DIGIT + url-parameters = *( ";" url-parameter ) + url-parameter = 1*(%x21-24 / %x26-3A / %x3C-7F / escaped) + ; Specific parameter definitions are for + ; further study. + ; The symbols "%", ";", and symbols + ; with a character value below 0x21 may be + ; represented as escaped sequences. + alphanum = ALPHA / DIGIT + escaped = "%" HEXDIG HEXDIG + + The host is case insensitive. + + + + +Levin Informational [Page 2] + +RFC 3508 H.323 URL Scheme April 2003 + + + The "user" is a Unicode [8] string that shall be UTF-8 [7] encoded + and then escaped as necessary. In the "user" field, the characters + with a numeric value below 0x80 are case insensitive and the + characters with a numeric value above or equal to 0x80 are case + sensitive. + + The character set and case sensitivity of the "url-parameter" is + specified in each parameter definition. + +3. Intended Usage + + The H.323 URL is intended to help an entity resolve the address of + another H.323 entity, where an "entity" may be a user, a device, or a + service. The "user" portion of the URL specifies an alias for the + entity, without carrying any information about the location of the + entity. The "hostport", on the other hand, is the domain name of an + Endpoint, Gatekeeper, Border Element, or other functional element to + which H.323 calls may be directed or for which services may be + performed. + +4. Applications and/or protocols, which may use H.323 URL scheme + + H.323 URLs may be carried by other protocols, such as SIP [6] or TRIP + [9]. H.323 URLs may be also contained within web pages or within XML + data, which may be utilized by H.323 entities in order to initiate + calls or perform services. + +5. Security Considerations + + When an H.323 URL is carried within H.225.0 [4] messages, security is + addressed by the H.235 security framework [5]. When an H.323 URL + carried within other protocols (such as SIP [6]), the security is + addressed within the corresponding protocol. + + In general, security, as it relates to the usage and carriage of the + H.323 URLs, is considered as an issue that should be addressed within + scope of H.323 or other relevant protocols and is not within the + scope of this document. + + + + + + + + + + + + + +Levin Informational [Page 3] + +RFC 3508 H.323 URL Scheme April 2003 + + +6. IANA Considerations + + The purpose of this document is serving as a reference point for the + purposes of registering the H.323 URL scheme with IANA. + + Having the URL registered with IANA will ensure that there is no + duplication of the URL scheme "h323". This document reproduces the + exact H323-URL definition as published in ITU-T Recommendation H.323 + [3]. + + Registration Template + + URL scheme name: h323 + + URL scheme syntax: Section 2 of RFC 3508 + + Character encoding considerations: Section 2 of RFC 3508 + + Intended usage: Section 3 of RFC 3508 + + Applications and/or protocols which use this scheme: Section 4 of + RFC 3508 + + Interoperability considerations: None. (Section 2 of RFC 3508 + contains the first version of "h323" URL definition.) + + Security considerations: Section 5 of RFC 3508 + + Relevant publications: [3] and [4] + + Contact: Orit Levin, orit@radvision.com + + Author/Change Controller: IESG + +References + + [1] Bradner, S., "Key words for use in RFCs to Indicate Requirement + Levels", BCP 14, RFC 2119, March 1997. + + [2] Crocker, D., Editor, and P. Overell "Augmented BNF for Syntax + Specifications: ABNF", RFC 2234, November 1997. + + [3] ITU-T Recommendation H.323v.4 "Packet-based multimedia + communications systems", November 2000. + + [4] ITU-T Recommendation H.225.0 "Call signalling protocols and + media stream packetization for packet-based multimedia + communication systems", November 2000. + + + +Levin Informational [Page 4] + +RFC 3508 H.323 URL Scheme April 2003 + + + [5] ITU-T Recommendation H.235 "Security and Encryption for H Series + (H.323 and other H.245 based) multimedia terminals", November + 2000. + + [6] Rosenberg, J., Schulzrinne, H., Camarillo, G., Johnston, A., + Peterson, J., Sparks, R., Handley, M. and E. Schooler, "SIP: + Session Initiation Protocol", RFC 3261, June 2002. + + [7] Yergeau, F., "UTF-8, a transformation format of ISO 10646", RFC + 2279, January 1998. + + [8] ISO/IEC 10646-1:1993, Information technology "Universal + Multiple-Octet Coded Character Set (USC)" Part 1: Architecture + and Basic Multilingual Plane. + + [9] Rosenberg, J., Salama, H. and M. Squire, "Telephony Routing over + IP (TRIP)", RFC 3219, January 2002. + +Acknowledgments + + This document is prepared and posted on behalf of SG-16 ITU-T. I + wish to thank Paul E. Jones, Robert Callaghan and Cullen Jennings for + their comments and active help. + +Author's Address + + Orit Levin + RADVISION + 266 Harristown Road + Glen Rock, NJ USA + + Phone: +1-201-689-6330 + EMail: orit@radvision.com + + + + + + + + + + + + + + + + + + +Levin Informational [Page 5] + +RFC 3508 H.323 URL Scheme April 2003 + + +Full Copyright Statement + + Copyright (C) The Internet Society (2003). All Rights Reserved. + + This document and translations of it may be copied and furnished to + others, and derivative works that comment on or otherwise explain it + or assist in its implementation may be prepared, copied, published + and distributed, in whole or in part, without restriction of any + kind, provided that the above copyright notice and this paragraph are + included on all such copies and derivative works. However, this + document itself may not be modified in any way, such as by removing + the copyright notice or references to the Internet Society or other + Internet organizations, except as needed for the purpose of + developing Internet standards in which case the procedures for + copyrights defined in the Internet Standards process must be + followed, or as required to translate it into languages other than + English. + + The limited permissions granted above are perpetual and will not be + revoked by the Internet Society or its successors or assigns. + + This document and the information contained herein is provided on an + "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING + TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING + BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION + HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF + MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. + +Acknowledgement + + Funding for the RFC Editor function is currently provided by the + Internet Society. + + + + + + + + + + + + + + + + + + + +Levin Informational [Page 6] + |