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Re: [sfc] TTL field within the NSH base header

James N Guichard <james.n.guichard@huawei.com> Mon, 01 May 2017 21:34 UTC

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From: James N Guichard <james.n.guichard@huawei.com>
To: Eric C Rosen <erosen@juniper.net>
CC: "sfc@ietf.org" <sfc@ietf.org>
Thread-Topic: [sfc] TTL field within the NSH base header
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Date: Mon, 01 May 2017 21:31:23 +0000
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Subject: Re: [sfc] TTL field within the NSH base header
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Hi Eric,

My personal opinion is that I agree with you.

What do others in the WG think?

Jim

From: Eric C Rosen [mailto:erosen@juniper.net]
Sent: Monday, May 01, 2017 2:29 PM
To: James N Guichard <james.n.guichard@huawei.com>
Cc: sfc@ietf.org
Subject: Re: [sfc] TTL field within the NSH base header

On 5/1/2017 1:38 PM, James N Guichard wrote:

SHL (SFF Hop Limit)

I hate to interrupt the discussion of modular arithmetic with a terminology issue, but I'd recommend against this terminology change.  "TTL" is a pretty well known term with a well known use.   Inventing a new acronym here can only cause confusion.  I don't think anyone's suggested modifying the IP specs to change "TTL" to "IP Hop Limit".

(Once upon a time, there was some thinking that it might take a packet more than a second to transit a router, and the original IP TTL requirement was to decrement the TTL by at least 1 per hop, but by more than 1 if the packet spent more than a second in a given router.  But for most of the last 40 years, everyone has known that "TTL" means "hop count".)

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