Re: [sipcore] RFC 4028 UAS behavior requirement of Require header

Brian Rosen <br@brianrosen.net> Fri, 28 May 2021 15:57 UTC

Return-Path: <br@brianrosen.net>
X-Original-To: sipcore@ietfa.amsl.com
Delivered-To: sipcore@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 9468E3A2CC8 for <sipcore@ietfa.amsl.com>; Fri, 28 May 2021 08:57:17 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.887
X-Spam-Level:
X-Spam-Status: No, score=-1.887 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, HTML_MESSAGE=0.001, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, T_SPF_PERMERROR=0.01, URIBL_BLOCKED=0.001] autolearn=ham autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (2048-bit key) header.d=brianrosen-net.20150623.gappssmtp.com
Received: from mail.ietf.org ([4.31.198.44]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id SbotpqplQXda for <sipcore@ietfa.amsl.com>; Fri, 28 May 2021 08:57:13 -0700 (PDT)
Received: from mail-il1-x12e.google.com (mail-il1-x12e.google.com [IPv6:2607:f8b0:4864:20::12e]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 485DB3A2C8F for <sipcore@ietf.org>; Fri, 28 May 2021 08:57:13 -0700 (PDT)
Received: by mail-il1-x12e.google.com with SMTP id h15so3730589ilr.2 for <sipcore@ietf.org>; Fri, 28 May 2021 08:57:13 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=brianrosen-net.20150623.gappssmtp.com; s=20150623; h=from:message-id:mime-version:subject:date:in-reply-to:cc:to :references; bh=C4iknmHWL0ZOvSlIade87fWBdEw+u1H/4bvRQXOm4/s=; b=ukfAP+sCvYrhXiuAgJ6Hi1DKXVRBjyqJMK/0VmKoZyT2nlfHj6DIX61RsB5uEyWMLM EyFPoNW5Bw0/i5Bfwu1fWQPcPu6PMsEQz54npvXkWKTmVmQnYmPecrv8/MwTLunOwTRx vPbXeF0+ruVWSSCk0NS8Tp6yX32j7Bnpy8LNUMUj46wqbVwf5PtBwsRkuHOQ68kb+mjR GBvhw42eGb9loyHh7lLunmzOKjI9wpCaHskAM8KMEn1nOiyAOBUnG++tEeb24A48xxxv lszYJozk103F+8yniHTl8BDOv3TFnKr9MBJhyySvsw97MbYgr0h6nQ7eF6d1RWfbXOmo BJSA==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:message-id:mime-version:subject:date :in-reply-to:cc:to:references; bh=C4iknmHWL0ZOvSlIade87fWBdEw+u1H/4bvRQXOm4/s=; b=nIxjHtTEW5WtZVUeXBuBve2cwKur/1ZlNF4F27tUJ6origmt8JPBU4rPhe5rlHui40 sZPCjtqSsPYV26aVJK/3b29i9n+W6WOkYqZHaN0JLyDfeF177qb/sIQTvfeFNJ2hn6kO 31s49yfXw1LNAlaK+W66gtr7w6PwpgDdF0rKoM7rWPIiGuNud+18NaoyPEDyU/x3CO9e FMgN77zS/TtqNiZdP1ACO534+OOmYRrC9ENsbOX/NjzqO21FpN7p+5UdoNZCAJiH3qBP ofzzxnzxgb4nFdik2104avFrizavvuM9k6UhzW/ZpmF9gjQCPPwx41fYzPbVC4cwYl3J NDWA==
X-Gm-Message-State: AOAM532ZtvZnrEyIGVKJOtsjKXnbxpK1T0eVV+hJrLDDdbodYTMXmair siGmLyK78Kq2YxSvg/h8oS2+bg==
X-Google-Smtp-Source: ABdhPJzk1FkYCDj+KNqS567Xp6X6c9sVWKEn7XypKqQ/6Ofd3eG902W07e0klTq0KmaBDUnX7sVn7w==
X-Received: by 2002:a92:6c0f:: with SMTP id h15mr7506584ilc.19.1622217431961; Fri, 28 May 2021 08:57:11 -0700 (PDT)
Received: from brians-mbp.lan (dynamic-acs-24-154-121-237.zoominternet.net. [24.154.121.237]) by smtp.gmail.com with ESMTPSA id w6sm3115803ilu.47.2021.05.28.08.57.11 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Fri, 28 May 2021 08:57:11 -0700 (PDT)
From: Brian Rosen <br@brianrosen.net>
Message-Id: <80EE14E6-AF9B-4042-A397-FE359AB040C7@brianrosen.net>
Content-Type: multipart/alternative; boundary="Apple-Mail=_30CFEED2-23DF-4AAF-A125-146F9A346D5B"
Mime-Version: 1.0 (Mac OS X Mail 14.0 \(3654.60.0.2.21\))
Date: Fri, 28 May 2021 11:57:10 -0400
In-Reply-To: <CO6PR02MB7603DC7C115904E3A41C9A95EE229@CO6PR02MB7603.namprd02.prod.outlook.com>
Cc: "sipcore@ietf.org" <sipcore@ietf.org>
To: Hoil Choi <hoil.choi@hotmail.com>
References: <CO6PR02MB7603DC7C115904E3A41C9A95EE229@CO6PR02MB7603.namprd02.prod.outlook.com>
X-Mailer: Apple Mail (2.3654.60.0.2.21)
Archived-At: <https://mailarchive.ietf.org/arch/msg/sipcore/Z963LpCwDnbQMOrRYPHoOUxmkDc>
Subject: Re: [sipcore] RFC 4028 UAS behavior requirement of Require header
X-BeenThere: sipcore@ietf.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: SIP Core Working Group <sipcore.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/sipcore>, <mailto:sipcore-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/sipcore/>
List-Post: <mailto:sipcore@ietf.org>
List-Help: <mailto:sipcore-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/sipcore>, <mailto:sipcore-request@ietf.org?subject=subscribe>
X-List-Received-Date: Fri, 28 May 2021 15:57:18 -0000

You should send this message to the sip-implementors list: sip-implementors@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/sip-implementors <https://lists.cs.columbia.edu/mailman/listinfo/sip-implementors>

> On May 28, 2021, at 3:08 AM, Hoil Choi <hoil.choi@hotmail.com> wrote:
> 
> Hello, 
> 
> I hope this mail finds appropriate person or team for an answer to my question on RFC 4028. 
> I am a SIP enthusiast and always learning a lot about it, but by no means am I an expert; so please excuse my ignorance.  
> 
> I came across an interesting statement In Section 9 UAS Behavior (or page 16).
> 
> If the refresher parameter in the Session-Expires header field in the
>    2xx response has a value of 'uac', the UAS MUST place a Require
>    header field into the response with the value 'timer'. 
> 
> Statement seems to convey that UAS must place a Require header with value 'timer' when UAC requests itself to be the refresher.  
> 
> However, this statement should only be true, if UAC did not put Session-Expire with value of 'uac'.  
> 
> If UAC, in INVITE request, put Session-Expire with value of 'uac' (itself), UAS should not bother putting Require header field in the response.  Or to be more accurate, UAC should include 'timer' in Supported header, so that UAS doesn't have to bother putting Require header field.  
> 
> What is the reason behind the requirement of Require header, from UAS in this case?
> 
> Thanks!
> Hoil Choi
> 253-273-5442
> 
> _______________________________________________
> sipcore mailing list
> sipcore@ietf.org <mailto:sipcore@ietf.org>
> https://www.ietf.org/mailman/listinfo/sipcore <https://www.ietf.org/mailman/listinfo/sipcore>