[Iptel] rfc4904: tgrp case sensitivity
Brett Tate <brett@broadsoft.com> Fri, 09 August 2013 13:48 UTC
Return-Path: <brett@broadsoft.com>
X-Original-To: iptel@ietfa.amsl.com
Delivered-To: iptel@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 396CA21F9F5C for <iptel@ietfa.amsl.com>; Fri, 9 Aug 2013 06:48:12 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -2.599
X-Spam-Level:
X-Spam-Status: No, score=-2.599 tagged_above=-999 required=5 tests=[BAYES_00=-2.599]
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 z3zgPX-+5kMI for <iptel@ietfa.amsl.com>; Fri, 9 Aug 2013 06:48:07 -0700 (PDT)
Received: from smtpout01.partnerhosted.com (smtpout01.partnerhosted.com [173.225.22.204]) by ietfa.amsl.com (Postfix) with ESMTP id 1E85611E80D2 for <iptel@ietf.org>; Fri, 9 Aug 2013 06:48:07 -0700 (PDT)
Received: from CASUMHUB03.citservers.local (172.16.98.219) by Xedge02.citservers.local (172.16.98.248) with Microsoft SMTP Server (TLS) id 14.2.247.3; Fri, 9 Aug 2013 06:48:22 -0700
Received: from MBX08.citservers.local ([fe80::2564:652:8dc8:caae]) by CASUMHUB03.citservers.local ([::1]) with mapi id 14.02.0247.003; Fri, 9 Aug 2013 06:48:22 -0700
From: Brett Tate <brett@broadsoft.com>
To: "iptel@ietf.org" <iptel@ietf.org>
Thread-Topic: rfc4904: tgrp case sensitivity
Thread-Index: Ac6VBxIcK/GRwRS9TWmBWPG/NOnU2A==
Date: Fri, 09 Aug 2013 13:48:21 +0000
Message-ID: <576A8B541C219D4E9CEB1DF8C19C7B881A059119@MBX08.citservers.local>
Accept-Language: en-US
Content-Language: en-US
X-MS-Has-Attach:
X-MS-TNEF-Correlator:
x-originating-ip: [172.16.98.77]
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0
Subject: [Iptel] rfc4904: tgrp case sensitivity
X-BeenThere: iptel@ietf.org
X-Mailman-Version: 2.1.12
Precedence: list
List-Id: IP Telephony <iptel.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/iptel>, <mailto:iptel-request@ietf.org?subject=unsubscribe>
List-Archive: <http://www.ietf.org/mail-archive/web/iptel>
List-Post: <mailto:iptel@ietf.org>
List-Help: <mailto:iptel-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/iptel>, <mailto:iptel-request@ietf.org?subject=subscribe>
X-List-Received-Date: Fri, 09 Aug 2013 13:48:12 -0000
Hi, Since I didn't much feedback on sip-implementors email list (thanks Hadriel), I thought that I'd try iptel. I find RFC 4904, RFC 3966, and RFC 3261 somewhat ambiguous concerning tgrp case sensitivity. I understand the rules from uri perspective: tgrp case-insensitive within telephone-uri, and tgrp case-sensitive within sip-uri. RFC 4904 section 5: "For equivalency purposes, two URIs containing trunk group parameters are equivalent according to the base comparison rules of the URIs. The base comparison rules of a tel URI are specified in Section 4 of [4], and the base comparison rules of a sip URI are specified in Section 19.1.4 of [3]." RFC 3966 section 4: "o URI comparisons are case-insensitive. All parameter names and values SHOULD use lower-case characters, as tel URIs may be used within contexts where comparisons are case sensitive." RFC 3261 section 19.1.6: "In general, equivalent "tel" URLs converted to SIP or SIPS URIs in this fashion may not produce equivalent SIP or SIPS URIs. The userinfo of SIP and SIPS URIs are compared as a case-sensitive string. Variance in case-insensitive portions of tel URLs and reordering of tel URL parameters does not affect tel URL equivalence, but does affect the equivalence of SIP URIs formed from them." "To mitigate this problem, elements constructing telephone-subscriber fields to place in the userinfo part of a SIP or SIPS URI SHOULD fold any case-insensitive portion of telephone-subscriber to lower case, and order the telephone-subscriber parameters lexically by parameter name, excepting isdn-subaddress and post-dial, which occur first and in that order. (All components of a tel URL except for future- extension parameters are defined to be compared case-insensitive.)" However once decoded/extracted out of the sip-uri or telephone-uri, is the tgrp value case sensitive? Since tgrp is case-insensitive within telephone-uri's telephone-subscriber (also used by sip-uri), I assume that the tgrp value is case-insensitive since it would be strange for the tgrp value to be context sensitive based upon if sent within sip-uri or telephone-uri. However, I also would not be surprised if someone said that nobody knows except for the owner of the trunk-context. RFC 4904 section 5 examples intentionally or unintentionally ignored RFC 3966 and RFC 3261 recommendation to use lower case. Thanks, Brett This email is intended solely for the person or entity to which it is addressed and may contain confidential and/or privileged information. If you are not the intended recipient and have received this email in error, please notify BroadSoft, Inc. immediately by replying to this message, and destroy all copies of this message, along with any attachment, prior to reading, distributing or copying it.
- [Iptel] rfc4904: tgrp case sensitivity Brett Tate