Subject: [Syslog] AD review comments for draft-ietf-syslog-dtls

From: Sean Turner <[email-masked]>
Date: Thu, 08 Apr 2010 16:06:09 -0500

I have one major comment and it relates to DCCP:

The DCCP chairs tell me that to specify the use of DCCP the ID needs to 
decide which CCID it will use (CCID 2 is AIMD and CCID 3 is TFRC).  I 
was hoping that the DTLS over DCCP RFC addressed this, but that RFC 
doesn't pick one it leaves this choice to the "application".

Can you also confirm that the Port # is used as the DCCP service code?

spt

---

From: Chris Lonvick <[email-masked]>
Date: Mon, 12 Apr 2010 06:40:28 -0700 (PDT)

Hi Folks,

I'll suggest CCID 3 because that's my lucky number.  ;-)

Seriously, here is a relevant point from RFC 5238:
===vvv===
    In addition to the retransmission issues, if the throughput needs of
    the actual application data differ from the needs of the DTLS
    handshake, it is possible that the handshake transference could leave
    the DCCP congestion control in a state that is not immediately
    suitable for the application data that will follow.  For example,
    DCCP Congestion Control Identifier (CCID) 2 ([RFC4341]) congestion
    control uses an Additive Increase Multiplicative Decrease (AIMD)
    algorithm similar to TCP congestion control.  If it is used, then it
    is possible that transference of a large handshake could cause a
    multiplicative decrease that would not have happened with the
    application data.  The application might then be throttled while
    waiting for additive increase to return throughput to acceptable
    levels.

    Applications where this might be a problem should consider using DCCP
    CCID 3 ([RFC4342]).  CCID 3 implements TCP-Friendly Rate Control
    (TFRC, [RFC3448])).  TFRC varies the allowed throughput more slowly
    than AIMD and might avoid the discontinuities possible with CCID 2.
===^^^===

My reasoning for choosing CCID 3 is that when some devices start up they 
will queue up syslog messages until the network is up, and then they will 
start to deliver them.  I don't want a large handshake to throttle that 
initial burst of messages.  (Please challenge this assumption if you have 
a better understanding of the process.)

I'll suggest that the specific wording will need to be: "MUST implement 
CCID 3 and SHOULD implement CCID 2 to ensure interoperability".  Does that 
sound OK to everyone?

Joe: can you look at Sean's second question and let us know about that?

Thanks,
Chris

On Thu, 8 Apr 2010, Sean Turner wrote:

> decide which CCID it will use (CCID 2 is AIMD and CCID 3 is TFRC).  I was 
> hoping that the DTLS over DCCP RFC addressed this, but that RFC doesn't pick 
> one it leaves this choice to the "application".
>
> _______________________________________________
> Syslog mailing list
> [email-masked]
> https://www.ietf.org/mailman/listinfo/syslog
>

---

From: "Joseph Salowey (jsalowey)" <[email-masked]>
Date: Wed, 21 Apr 2010 21:24:35 -0700

Hi Chris,

CCID 3 looks good to me, I'm OK with the text. 

We could just use the port number, 6514, as the service code. Since the
service identifier applies to more than DCCP, it probably makes more
sense the follow the scheme defined in RFC4340 where a 4 letter string
is used as the service identifier, such as the following:

SC:SYLG
SC=x53594C47
SC=1398361159

Cheers,

Joe
> -----Original Message-----
> From: [email-masked] [mailto:[email-masked]] On
Behalf
> Of Chris Lonvick (clonvick)
> Sent: Monday, April 12, 2010 6:40 AM
> To: [email-masked]
> Subject: Re: [Syslog] AD review comments for draft-ietf-syslog-dtls
> 
> Hi Folks,
> 
> was
> > hoping that the DTLS over DCCP RFC addressed this, but that RFC
doesn't
> pick

---

From: Sean Turner <[email-masked]>
Date: Thu, 22 Apr 2010 18:54:51 -0400

I'm fine with either.  Regardless, the IANA considerations section needs 
to be updated to register the service code - unless some other document 
that I don't know about already did.  Notes for the registration can be 
found here: 
http://www.iana.org/assignments/service-codes/service-codes.xhtml

But, all that I think is needed is some text asking IANA to register the 
following DCCP service code:

   1398361159   SYLG   SYSLOG Protocol    [TBD]

spt

---

From: "Joseph Salowey (jsalowey)" <[email-masked]>
Date: Fri, 23 Apr 2010 08:02:41 -0700

Anybody on the list have objection to adding the Chris' suggested text
and the DCCP service code SYLG?

Thanks,

Joe

> From: Sean Turner [mailto:[email-masked]]
> Sent: Thursday, April 22, 2010 3:55 PM
> To: Joseph Salowey (jsalowey); Chris Lonvick (clonvick)
> Cc: [email-masked]
> >>     In addition to the retransmission issues, if the throughput
needs
> > of
> >>     algorithm similar to TCP congestion control.  If it is used,
then
> > it
> >>     Applications where this might be a problem should consider
using
> > DCCP
> >>     than AIMD and might avoid the discontinuities possible with
CCID
> > 2.
> >> will queue up syslog messages until the network is up, and then
they
> > will
> >> initial burst of messages.  (Please challenge this assumption if
you
> > have
> >> CCID 3 and SHOULD implement CCID 2 to ensure interoperability".
Does
> > that
> >>> The DCCP chairs tell me that to specify the use of DCCP the ID
needs
> > to

---

From: "tom.petch" <[email-masked]>
Date: Tue, 27 Apr 2010 16:34:50 +0200

----- Original Message -----
From: "Joseph Salowey (jsalowey)" <[email-masked]>
To: "Sean Turner" <[email-masked]>; "Chris Lonvick (clonvick)"
<[email-masked]>
Cc: <[email-masked]>
Sent: Friday, April 23, 2010 5:02 PM

> and the DCCP service code SYLG?

I see SYSL used as a four character code for syslog in other settings and would
prefer that.  Else, following the principle of dropping vowels, SSLG, but I
think that not as good.

Tom Petch