From nobody Fri May 28 12:38:41 2021 Return-Path: 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 052C53A3331 for ; Fri, 28 May 2021 12:38:39 -0700 (PDT) X-Virus-Scanned: amavisd-new at amsl.com X-Spam-Flag: NO X-Spam-Score: -1.847 X-Spam-Level: X-Spam-Status: No, score=-1.847 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, FREEMAIL_ENVFROM_END_DIGIT=0.25, FREEMAIL_FROM=0.001, HTML_MESSAGE=0.001, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001] autolearn=ham autolearn_force=no Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (2048-bit key) header.d=gmail.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 YkS6wCp0GATw for ; Fri, 28 May 2021 12:38:37 -0700 (PDT) Received: from mail-ej1-x62b.google.com (mail-ej1-x62b.google.com [IPv6:2a00:1450:4864:20::62b]) (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 27E903A3330 for ; Fri, 28 May 2021 12:38:37 -0700 (PDT) Received: by mail-ej1-x62b.google.com with SMTP id z12so7101331ejw.0 for ; Fri, 28 May 2021 12:38:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=cbPmnqe5cCbqtTR3vIkqmWcdForh8jbH/LMYtj27JCk=; b=JdWoNLpgBfVle5TzO7g9XADApKY2Z27jOmjrErJslB40foL2dlVFewWu2fCNEilhi4 eJT62npFsoFlGcNmwBo6X94x4CjvzNzf3nm15Hs06gHTHnMNyFTr+2hT4j2+l9Bm6x3p MAfArbvalebNhvc+AkXgbivCuSvw9VUgBJejJSV9XKNRN8bE6rF6r5pwEBEFkCz7n2ua chzGJKusP1P68DI9DE7/SbEpniyZuhTdAiI5eI2eUy8XPAGbrWO+6kTyTimxmL/gGLah 7z8oAkL5I8F0+eNz/bgc1bTZmPLsn34xH1djRd9DuH67Z8lTutCasT0xiNY5yBKv+dER Nyvg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=cbPmnqe5cCbqtTR3vIkqmWcdForh8jbH/LMYtj27JCk=; b=nkG6+GblspjtLsfGah7blrO0eFwDbkSBGN5VreaD1hfh0je89kIG5Ng2iD6HF6lM+K Kq/+Neoy1FeOza3d5yE4AMJxZJX3zjZp+klGcQC6ffEdb4wv6vIVjwKYgmNZWBk6oomM yRr/3CkMlBNPKFGV3EcgrRcXKP7DD8dT22Rs7sLCUtK9tHvsncyBOo4sm/uwqsaUURnB sWU9pQSjOiZePE/bJK3Q7scuFL8qDB03eavBk7R0m7B6gAmFfKly+agVT04I7odUbEgs jmbZMqtD5y9j8Fc3fsUGIxZ+8D8wFiu0V9byQePV9TvZYRXVcindTA3BqkZXsGVtqTq/ eg5w== X-Gm-Message-State: AOAM530nEi3CxxxGdUlLw70ISZ1io/wki7LcdtiPpnvqjmGFcu08a/kz 5jf2iLMUTPBVYHpa7kTsJWgyGbNPcH7xCtqBE+w= X-Google-Smtp-Source: ABdhPJyCGB8Wj8JpugYxBLvGTPzt3+p3qvjLQu4gI4wQqRobvfAeXVEJK1M5BmX9w/x0wxm3SNCuWOT4lRmQ4yClBJ8= X-Received: by 2002:a17:906:55d6:: with SMTP id z22mr10685008ejp.355.1622230714037; Fri, 28 May 2021 12:38:34 -0700 (PDT) MIME-Version: 1.0 References: In-Reply-To: From: Ranjit Avasarala Date: Fri, 28 May 2021 14:38:09 -0500 Message-ID: To: Hoil Choi , Sip-implementors@lists.cs.columbia.edu Cc: "sipcore@ietf.org" Content-Type: multipart/alternative; boundary="0000000000007437f205c3690590" Archived-At: 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 List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 28 May 2021 19:38:39 -0000 --0000000000007437f205c3690590 Content-Type: text/plain; charset="UTF-8" Hi Holi the presence of the "Require" header with value "timer" from UAS indicates to UAC that it (UAC) is performing the refreshing operation. but if the UAS is the refresher, then if Require header with value "timer" is present in response from UAS, then UAC should send BYE if it does not receive a session refresh request from UAS. Regards Ranjit On Fri, May 28, 2021 at 10:02 AM Hoil Choi 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 > https://www.ietf.org/mailman/listinfo/sipcore > --0000000000007437f205c3690590 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
Hi Holi
the presence of the "Require" header= with value "timer" from UAS indicates to UAC that it (UAC) is pe= rforming the refreshing operation. but if the UAS is the refresher, then if= Require header with value "timer" is present in response from UA= S, then UAC should send BYE if it does not receive a session refresh reques= t from UAS.

Regards
Ranjit


On Fri, May 28, 2021 at 10:02 AM Hoil Choi <hoil.choi@hotmail.com> wrote:
=
Hello,=C2=A0

I hope this mail finds appropriate person or team for an answer to my quest= ion on RFC 4028.=C2=A0
I am a SIP enthusiast and always learning a lot about it, but by no means a= m I an expert; so please excuse my ignorance. =C2=A0

I came across an interesting statement In Section 9 UAS Behavior (or page 1= 6).

If the refresher parameter in the Session-Expire=
s header field in the
=C2=A0 =C2=A02xx response has a value of 'uac', the UAS MUST place =
a Require
=C2=A0 =C2=A0header field into the response with the value 'timer'.=

Statement seems to convey that UAS must place a Require header with value &= #39;timer' when UAC requests itself to be the refresher. =C2=A0

However, this statement should only be true, if UAC did not put Session-Exp= ire with value of 'uac'. =C2=A0

If UAC, in INVITE request, put Session-Expire with value of 'uac' (= itself), UAS should not bother putting Require header field in the response= .=C2=A0 Or to be more accurate, UAC should include 'timer' in Suppo= rted header, so that UAS doesn't have to bother putting Require header field. =C2=A0

What is the reason behind the requirement of Require header, from UAS in th= is case?

Thanks!
Hoil Choi
253-273-5442

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