RFC 3508 (rfc3508) - Page 2 of 6
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Alternative Format: Original Text Document
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
