Subject: [DNSOP] I-D Action: draft-bellis-dnsop-session-signal-01.txt

From: [email-masked]
Date: Thu, 21 Jul 2016 09:48:56 -0700

A New Internet-Draft is available from the on-line Internet-Drafts directories.
This draft is a work item of the Domain Name System Operations of the IETF.

        Title           : DNS Session Signaling
        Authors         : Ray Bellis
                          Stuart Cheshire
                          John Dickinson
                          Sara Dickinson
                          Allison Mankin
                          Tom Pusateri
	Filename        : draft-bellis-dnsop-session-signal-01.txt
	Pages           : 11
	Date            : 2016-07-21

Abstract:
   The Extension Mechanisms for DNS (EDNS(0)) [RFC6891] is explicitly
   defined to only have "per-message" semantics.  This document defines
   a new Session Signaling OpCode used to carry persistent "per-session"
   type-length-values (TLVs), and defines an initial set of TLVs used to
   manage session timeouts and termination.

The IETF datatracker status page for this draft is:
https://datatracker.ietf.org/doc/draft-bellis-dnsop-session-signal/

There's also a htmlized version available at:
https://tools.ietf.org/html/draft-bellis-dnsop-session-signal-01

A diff from the previous version is available at:
https://www.ietf.org/rfcdiff?url2=draft-bellis-dnsop-session-signal-01

Please note that it may take a couple of minutes from the time of submission
until the htmlized version and diff are available at tools.ietf.org.

Internet-Drafts are also available by anonymous FTP at:
ftp://ftp.ietf.org/internet-drafts/

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From: "Jan Komissar (jkomissa)" <[email-masked]>
Date: Fri, 22 Jul 2016 19:30:09 +0000

Hi,

Here's my comments to version 1 of this draft.

3.1 Message Format

I'm a little hesitant about going to the 4-octet header. Are we certain
that most existing DNS servers will respond with NOTIMP rather than
FORMERR upon receipt of a ses-sig message? Some servers may not even
respond to packets smaller than 12 octets (DNS header size). I would
prefer using the full DNS header, even if it wastes 8 octets.

I do like the simplification of only allowing one TLV per message.

3.2 Message Handling

I'm still uncertain about ses-sig messages being "sequencing points" (see
my comments to version 00 of this draft). In addition, where do server
initiated messages, such as DNS Push Notification updates, fit into this?

4.2.1 Start Session

I like using the Start Session TLV as a no-op/I'm still here message.

4.2.2 Terminate Session

The current DNS Push Notification draft specifies different Reconnect
Delays in different cases. Maybe there should be suggestions for multiple
delay values, depending on the kinds of reasons for termination (server
shutdown, server restart, different kinds of client errors). Out maybe
just mentioning that as a valid option.

4.2.3. Idle Timeout

I'm not sure of the usefulness of querying for the timeout value, the
client should already have received it if one applies. However, I see no
harm in that feature.

5. IANA Considerations

Nits: Should it be "IANA is directed.."?

Regards,

Jan Komissar