Re: [sipcore] Benjamin Kaduk's No Objection on draft-ietf-sipcore-originating-cdiv-parameter-07: (with COMMENT)

Paul Kyzivat <pkyzivat@alum.mit.edu> Thu, 06 December 2018 16:37 UTC

To: Benjamin Kaduk <kaduk@mit.edu>
References: <154408822794.3503.4205493528646048224.idtracker@ietfa.amsl.com>
From: Paul Kyzivat <pkyzivat@alum.mit.edu>
Cc: sipcore@ietf.org
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Date: Thu, 06 Dec 2018 11:37:03 -0500
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Subject: Re: [sipcore] Benjamin Kaduk's No Objection on draft-ietf-sipcore-originating-cdiv-parameter-07: (with COMMENT)
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On 12/6/18 4:23 AM, Benjamin Kaduk wrote:

>     sessioncase-param        = "sescase" EQUAL ("orig"/"term")/ orig-cdiv
> 
> It's quite possible I'm just confused about the ABNF, but why do we need the
> grouping?

IIUC, you are asking if the above:

1) sessioncase-param  = "sescase" EQUAL ("orig"/"term")/ orig-cdiv

is equivalent to:

2) sessioncase-param  = "sescase" EQUAL "orig"/"term"/ orig-cdiv

The answer is no, it isn't. Using more bracketing to show the syntax 
more clearly, (1) is equivalent to:

1a) sessioncase-param  = ("sescase" EQUAL ("orig"/"term")) / orig-cdiv

while (2) is equivalent to:

2a) sessioncase-param  = ("sescase" EQUAL "orig") / "term" / orig-cdiv

	Thanks,
	Paul

[sipcore] Benjamin Kaduk's No Objection on draft-… Benjamin Kaduk
Re: [sipcore] Benjamin Kaduk's No Objection on dr… Paul Kyzivat
Re: [sipcore] Benjamin Kaduk's No Objection on dr… marianne.mohali
Re: [sipcore] Benjamin Kaduk's No Objection on dr… Benjamin Kaduk