Re: [Uri-review] In WG last call review of URI Schemes rtsp, rtsps and rtspu
Larry Masinter <masinter@adobe.com> Mon, 07 May 2012 23:28 UTC
Return-Path: <masinter@adobe.com>
X-Original-To: uri-review@ietfa.amsl.com
Delivered-To: uri-review@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 272B421F8691 for <uri-review@ietfa.amsl.com>; Mon, 7 May 2012 16:28:10 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -107.599
X-Spam-Level:
X-Spam-Status: No, score=-107.599 tagged_above=-999 required=5 tests=[AWL=1.000, BAYES_00=-2.599, GB_I_LETTER=-2, RCVD_IN_DNSWL_MED=-4, USER_IN_WHITELIST=-100]
Received: from mail.ietf.org ([12.22.58.30]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id FgJ09fR3r9+e for <uri-review@ietfa.amsl.com>; Mon, 7 May 2012 16:28:09 -0700 (PDT)
Received: from exprod6og101.obsmtp.com (exprod6og101.obsmtp.com [64.18.1.181]) by ietfa.amsl.com (Postfix) with ESMTP id A2F9621F866B for <uri-review@ietf.org>; Mon, 7 May 2012 16:27:59 -0700 (PDT)
Received: from outbound-smtp-2.corp.adobe.com ([193.104.215.16]) by exprod6ob101.postini.com ([64.18.5.12]) with SMTP ID DSNKT6haft5w9XCa6dq0c23fiwLXiVvo3trh@postini.com; Mon, 07 May 2012 16:28:08 PDT
Received: from inner-relay-1.corp.adobe.com (ms-exchange.macromedia.com [153.32.1.51]) by outbound-smtp-2.corp.adobe.com (8.12.10/8.12.10) with ESMTP id q47NRtIf002250; Mon, 7 May 2012 16:27:56 -0700 (PDT)
Received: from nahub02.corp.adobe.com (nahub02.corp.adobe.com [10.8.189.98]) by inner-relay-1.corp.adobe.com (8.12.10/8.12.10) with ESMTP id q47NRtvm021444; Mon, 7 May 2012 16:27:55 -0700 (PDT)
Received: from SJ1SWM219.corp.adobe.com (10.5.77.61) by nahub02.corp.adobe.com (10.8.189.98) with Microsoft SMTP Server (TLS) id 8.3.192.1; Mon, 7 May 2012 16:27:54 -0700
Received: from nambxv01a.corp.adobe.com ([10.8.189.95]) by SJ1SWM219.corp.adobe.com ([fe80::d55c:7209:7a34:fcf7%12]) with mapi; Mon, 7 May 2012 16:27:54 -0700
From: Larry Masinter <masinter@adobe.com>
To: Magnus Westerlund <magnus.westerlund@ericsson.com>, Ted Hardie <ted.ietf@gmail.com>
Date: Mon, 07 May 2012 16:27:53 -0700
Thread-Topic: [Uri-review] In WG last call review of URI Schemes rtsp, rtsps and rtspu
Thread-Index: Ac0oZqtt6oyhWe7FSkO63PRg9hvz9QEQcmZg
Message-ID: <C68CB012D9182D408CED7B884F441D4D194AD547DE@nambxv01a.corp.adobe.com>
References: <4F99665D.8060404@ericsson.com> <CA+9kkMAvr6eXHzB_HMVgGqBHpUpeuh-mrWRP6-Ap0w3SZLvV-Q@mail.gmail.com> <4FA13522.6020103@ericsson.com>
In-Reply-To: <4FA13522.6020103@ericsson.com>
Accept-Language: en-US
Content-Language: en-US
X-MS-Has-Attach:
X-MS-TNEF-Correlator:
acceptlanguage: en-US
Content-Type: text/plain; charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0
Cc: "uri-review@ietf.org" <uri-review@ietf.org>, "mmusic-chairs@tools.ietf.org" <mmusic-chairs@tools.ietf.org>
Subject: Re: [Uri-review] In WG last call review of URI Schemes rtsp, rtsps and rtspu
X-BeenThere: uri-review@ietf.org
X-Mailman-Version: 2.1.12
Precedence: list
List-Id: Proposed URI Schemes <uri-review.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/uri-review>, <mailto:uri-review-request@ietf.org?subject=unsubscribe>
List-Archive: <http://www.ietf.org/mail-archive/web/uri-review>
List-Post: <mailto:uri-review@ietf.org>
List-Help: <mailto:uri-review-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/uri-review>, <mailto:uri-review-request@ietf.org?subject=subscribe>
X-List-Received-Date: Mon, 07 May 2012 23:28:10 -0000
Please note that the URI/IRI registration guidelines (4395bis) have a proposed "fix": http://wiki.tools.ietf.org/wg/iri/trac/ticket/125 to add the sentence: "However, the registration defines <scheme> and the syntax and semantics of <fragment> depends only on the media type of the representation accessed. New scheme definitions MUST NOT define syntax or semantics of fragment identifiers; that is, registration specifications should define the syntax of <scheme-specific-part> and its meaning for each <scheme> defined." That is, the recommendation is that scheme registrations do *not* specify the syntax or meaning of fragment identifiers. So "Added a fragment part to the RTSP URI. " might not be considered an improvement. Regards, Larry -- http://larry.masinter.net -----Original Message----- From: uri-review-bounces@ietf.org On Behalf Of Magnus Westerlund Sent: Wednesday, May 02, 2012 6:23 AM To: Ted Hardie Cc: uri-review@ietf.org; mmusic-chairs@tools.ietf.org Subject: Re: [Uri-review] In WG last call review of URI Schemes rtsp, rtsps and rtspu Hi Ted, Thanks for the review. On 2012-04-27 16:40, Ted Hardie wrote: > Howdy, > > The registrations below note that there were changes in URI syntax. I > could not find a summary of > them in 2326bis; can you provide a pointer? The changes section in the I-D says the following that applies to the URI. * Added a fragment part to the RTSP URI. This seemed to be indicated by the note below the definition, however, it was not part of the ABNF. Which is clearly not the whole story. Thus I have also checked the Syntax differences between the two specs. RFC2326 defines the URI as: rtsp_URL = ( "rtsp:" | "rtspu:" ) "//" host [ ":" port ] [ abs_path ] host = <A legal Internet host domain name of IP address (in dotted decimal form), as defined by Section 2.1 of RFC 1123> port = *DIGIT abs_path is defined in [H3.2.1]. >From RFC 2068: abs_path = "/" rel_path rel_path = [ path ] [ ";" params ] [ "?" query ] path = fsegment *( "/" segment ) fsegment = 1*pchar segment = *pchar params = param *( ";" param ) param = *( pchar | "/" ) scheme = 1*( ALPHA | DIGIT | "+" | "-" | "." ) net_loc = *( pchar | ";" | "?" ) query = *( uchar | reserved ) fragment = *( uchar | reserved ) pchar = uchar | ":" | "@" | "&" | "=" | "+" uchar = unreserved | escape unreserved = ALPHA | DIGIT | safe | extra | national escape = "%" HEX HEX reserved = ";" | "/" | "?" | ":" | "@" | "&" | "=" | "+" extra = "!" | "*" | "'" | "(" | ")" | "," safe = "$" | "-" | "_" | "." unsafe = CTL | SP | <"> | "#" | "%" | "<" | ">" national = <any OCTET excluding ALPHA, DIGIT, reserved, extra, safe, and unsafe> While draft-ietf-mmusic-rfc2326bis-29 defines it as: RTSP-URI = schemes ":" URI-rest RTSP-REQ-URI = schemes ":" URI-req-rest RTSP-URI-Ref = RTSP-URI / RTSP-Relative RTSP-REQ-Ref = RTSP-REQ-URI / RTSP-REQ-Rel schemes = "rtsp" / "rtsps" / scheme scheme = < As defined in RFC 3986> URI-rest = hier-part [ "?" query ] [ "#" fragment ] URI-req-rest = hier-part [ "?" query ] ; Note fragment part not allowed in requests hier-part = "//" authority path-abempty RTSP-Relative = relative-part [ "?" query ] [ "#" fragment ] RTSP-REQ-Rel = relative-part [ "?" query ] relative-part = "//" authority path-abempty / path-absolute / path-noscheme / path-empty authority = < As defined in RFC 3986> query = < As defined in RFC 3986> fragment = < As defined in RFC 3986> path = path-abempty ; begins with "/" or is empty / path-absolute ; begins with "/" but not "//" / path-noscheme ; begins with a non-colon segment / path-rootless ; begins with a segment / path-empty ; zero characters path-abempty = *( "/" segment ) path-absolute = "/" [ segment-nz *( "/" segment ) ] path-noscheme = segment-nz-nc *( "/" segment ) path-rootless = segment-nz *( "/" segment ) path-empty = 0<pchar> segment = *pchar [";" *pchar] segment-nz = ( 1*pchar [";" *pchar]) / (";" *pchar) segment-nz-nc = ( 1*pchar-nc [";" *pchar-nc]) / (";" *pchar-nc) ; non-zero-length segment without any colon ":" UPALPHA = %x41-5A ; any US-ASCII uppercase letter "A".."Z" LOALPHA = %x61-7A ;any US-ASCII lowercase letter "a".."z" ALPHA = UPALPHA / LOALPHA DIGIT = %x30-39 ; any US-ASCII digit "0".."9" safe = "$" / "-" / "_" / "." / "+" extra = "!" / "*" / "'" / "(" / ")" / "," unreserved = ALPHA / DIGIT / safe / extra pct-encoded = < As defined in RFC 3987> pchar = unreserved / pct-encoded / sub-delims / ":" / "@" pchar-nc = unreserved / pct-encoded / sub-delims / "@" sub-delims = "!" / "$" / "&" / "'" / "(" / ")" / "*" / "+" / "," / "=" So actual changes for the rtsp scheme I have found are: - Fragments added with syntax. As the previous change comments says there are discussion of URI fragments in RFC2326 but no syntax defined. However, fragments are not allowed in request URIs. - Support for IPV6 literal in host part and future IP literals through RFC 3986 defined mechanism. - It defines a relative format to use in RTSP protocol elements that is not required to start with "/". This was not allowed in RFC2326 due to the syntax definition. There might be more but I have reviewed the syntax fairly careful. But In addition the URI related changes the ID does are: - Defining the syntax for the rtsps scheme which is in use but not defined. - Register the rtspu scheme defined in RFC 2326 but not registered. > > rtsp was already registered in the URI Schemes registry as permanent; > significant changes to the syntax > would probably require minting a new scheme to avoid the > interoperability problems you note below. I agree that if we would have significant changes it would be problematic. At the same time introducing a new scheme for rtsp would also have been problematic. I consider the above changes to be minor and to extend the functionality of the old definition, not change what has existed since RFC 2326. The new extended functionality can cause failure if you try to use these. Thus the documentation of these changes needs to be improved. I will take it as WG last call comment. Cheers Magnus Westerlund ---------------------------------------------------------------------- Multimedia Technologies, Ericsson Research EAB/TVM ---------------------------------------------------------------------- Ericsson AB | Phone +46 10 7148287 Färögatan 6 | Mobile +46 73 0949079 SE-164 80 Stockholm, Sweden| mailto: magnus.westerlund@ericsson.com ---------------------------------------------------------------------- _______________________________________________ Uri-review mailing list Uri-review@ietf.org https://www.ietf.org/mailman/listinfo/uri-review
- [Uri-review] In WG last call review of URI Scheme… Magnus Westerlund
- Re: [Uri-review] In WG last call review of URI Sc… Ted Hardie
- Re: [Uri-review] In WG last call review of URI Sc… Magnus Westerlund
- Re: [Uri-review] In WG last call review of URI Sc… Larry Masinter
- Re: [Uri-review] In WG last call review of URI Sc… Magnus Westerlund
- Re: [Uri-review] In WG last call review of URI Sc… Julian Reschke
- Re: [Uri-review] In WG last call review of URI Sc… Magnus Westerlund
- Re: [Uri-review] In WG last call review of URI Sc… Larry Masinter
- Re: [Uri-review] In WG last call review of URI Sc… Julian Reschke
- Re: [Uri-review] In WG last call review of URI Sc… Ted Hardie
- Re: [Uri-review] In WG last call review of URI Sc… Larry Masinter
- Re: [Uri-review] In WG last call review of URI Sc… Julian Reschke
- Re: [Uri-review] In WG last call review of URI Sc… Ted Hardie
- Re: [Uri-review] In WG last call review of URI Sc… Roy T. Fielding
- Re: [Uri-review] In WG last call review of URI Sc… Ted Hardie
- Re: [Uri-review] In WG last call review of URI Sc… Martin J. Dürst
- Re: [Uri-review] In WG last call review of URI Sc… Roy T. Fielding
- Re: [Uri-review] In WG last call review of URI Sc… Martin J. Dürst
- Re: [Uri-review] In WG last call review of URI Sc… Ted Hardie
- Re: [Uri-review] In WG last call review of URI Sc… Roy T. Fielding
- Re: [Uri-review] In WG last call review of URI Sc… Martin J. Dürst