Re: [Pals] RFC4447bis LC and label request/response discussion in Prague

Matthew,

I agree. Our intent isn't only to require a complete implementation of
5036, but to also require that a PE respond to a PW FEC label request. This
is a specific change to section 3.5.8.1 of 5036, which only says that a PE
SHOULD respond to a label request message.

Here is some specific recommended text for 4447bis:

OLD:

LDP MUST exchange PW FEC label bindings in downstream unsolicited
manner, independent of the negotiated label advertisement mode of the
LDP session according to the specifications in specified in [RFC7358].
LDP's "liberal label retention" mode SHOULD be used.

NEW:

LDP MUST exchange PW FEC label bindings in Downstream Unsolicited
mode, independent of the negotiated label advertisement mode of the
LDP session, as according to the specifications in [RFC7358].
LDP's Liberal Label retention mode SHOULD be used. All the LDP
procedures specified in [RFC5036] MUST be implemented. In addition,
this document updates section 3.5.8.1 of [RFC5036] to require that
a receiving LSR MUST (rather than SHOULD) respond to a Label Request
message with a Label Mapping for the requested label or with a
Notification message indicating why it cannot satisfy the request.

Cheers,
Andy

On Tue, Aug 4, 2015 at 3:36 AM, Bocci, Matthew (Matthew) <
matthew.bocci@alcatel-lucent.com> wrote:

> Hi Andy
>
> I think the intent is as per Patrice’s comment. That is, a PE MUST respond
> to a PW FEC label request, not SHOULD. Therefore it might be clearer to
> explicitly state this in 4447bis (rather than by reference) and also note
> at the top of the draft that we are updating RFC5036.
>
> Matthew
>
> From: "Andrew G. Malis" <agmalis@gmail.com>
> Date: Saturday, 1 August 2015 17:41
> To: Matthew Bocci <matthew.bocci@alcatel-lucent.com>
> Cc: Luca Martini <lmartini@cisco.com>, "Patrice Brissette (pbrisset)" <
> pbrisset@cisco.com>, "pals@ietf.org" <pals@ietf.org>
>
> Subject: Re: [Pals] RFC4447bis LC and label request/response discussion
> in Prague
>
> Matthew,
>
> I saw that text, but nothing in Luca's new text makes that a MUST, it just
> says that you MUST implement that procedure as written (which is a SHOULD).
>
> Cheers,
> Andy
>
>
> On Sat, Aug 1, 2015 at 12:25 PM, Bocci, Matthew (Matthew) <
> matthew.bocci@alcatel-lucent.com> wrote:
>
>> Andy, Luca,
>>
>> 3.5.8.1 says the following:
>>
>> "The receiving LSR SHOULD respond to a Label Request message with a
>>
>>    Label Mapping for the requested label or with a Notification message
>>    indicating why it cannot satisfy the request.”
>>
>>
>>
>> Matthew
>>
>>
>> From: "Andrew G. Malis" <agmalis@gmail.com>
>> Date: Saturday, 1 August 2015 16:39
>> To: Luca Martini <lmartini@cisco.com>
>> Cc: Matthew Bocci <matthew.bocci@alcatel-lucent.com>, "Patrice Brissette
>> (pbrisset)" <pbrisset@cisco.com>, "pals@ietf.org" <pals@ietf.org>
>> Subject: Re: [Pals] RFC4447bis LC and label request/response discussion
>> in Prague
>>
>> I've also just scanned through 5036, and I'm also not sure exactly what
>> text Matthew is referring to. I don't see a specific SHOULD that Luca's
>> text would change to a MUST.
>>
>> Cheers,
>> Andy
>>
>>
>> On Fri, Jul 31, 2015 at 5:58 PM, Luca Martini <lmartini@cisco.com> wrote:
>>
>>> Matthew,
>>>
>>> can you point out the SHOULD in rfc5036 to me ? I could not find it
>>> explicitly in the text. Are you referring to the appendix ?
>>> Thanks.
>>> Luca
>>>
>>>
>>> On 07/30/15 13:18, Bocci, Matthew (Matthew) wrote:
>>> > Luca
>>> >
>>> > I don¡¯t object to the intent, but I agree with Andy that there is
>>> > something strange about calling out those sections specifically. You
>>> are
>>> > upgrading the RFC2119 requirement around label request because
>>> responding
>>> > to a label request is a SHOULD in RFC5036, but a MUST here.
>>> >
>>> > Are there any other cases where we really need an implementation to do
>>> > something that is only a SHOULD in RFC5036?
>>> >
>>> > Matthew
>>> >
>>> > On 30/07/2015 19:50, "Pals on behalf of Patrice Brissette (pbrisset)"
>>> > <pals-bounces@ietf.org on behalf of pbrisset@cisco.com> wrote:
>>> >
>>> >> Hi,
>>> >>
>>> >>
>>> >> I don©öt have a strong opinion as long it is clear to everyone that a
>>> PE
>>> >> MUST respond to PW FEC label request.
>>> >>
>>> >>
>>> >> Regards,
>>> >>
>>> >> Patrice
>>> >>
>>> >>   Patrice Brissette
>>> >> TECHNICAL LEADER.ENGINEERING
>>> >>
>>> >> pbrisset@cisco.com
>>> >> Phone: +1 613 254 3336
>>> >>
>>> >> Cisco Systems Canada Co. / Les Systemes Cisco Canada CIE
>>> >> Canada
>>> >> Cisco.com <http://www.cisco.com/global/CA/>
>>> >>
>>> >> Think before you print.This
>>> >> email may contain confidential and privileged material for the sole
>>> use
>>> >> of the intended recipient. Any review, use, distribution or disclosure
>>> >> by others is strictly prohibited. If you are not the intended
>>> recipient
>>> >> (or authorized to receive for the recipient), please contact the
>>> sender
>>> >> by reply email and delete all copies of this message.
>>> >> Please click here
>>> >> <http://www.cisco.com/web/about/doing_business/legal/cri/index.html>
>>> for
>>> >> Company Registration Information.
>>> >>
>>> >>
>>> >>
>>> >>
>>> >>
>>> >>
>>> >> On 2015-07-27, 7:55 PM, "Pals on behalf of Luca Martini (lmartini)"
>>> >> <pals-bounces@ietf.org on behalf of lmartini@cisco.com> wrote:
>>> >>
>>> >>> On 07/27/2015 01:59 PM, Andrew G. Malis wrote:
>>> >>>> Luca,
>>> >>>>
>>> >>>> RFC 5036 uses "Downstream Unsolicited mode" rather than "downstream
>>> >>>> unsolicited
>>> >>>> manner", so you should change "manner" to "mode" and capitalize
>>> >>>> Downstream
>>> >>>> Unsolicited. It also uses "Liberal Label retention mode" (note the
>>> >>>> capital L's
>>> >>>> and small r and m).
>>> >>> yes - Agreed.
>>> >>>
>>> >>>> Regarding your new text "However all the LDP procedures specified in
>>> >>>> [RFC5036]
>>> >>>> MUST be implemented, and specifically the procedures in section
>>> 3.5.7.
>>> >>>> "Label
>>> >>>> Mapping Message", and   3.5.8. "Label Request Message".", I would
>>> just
>>> >>>> shorten
>>> >>>> it to say: "However, all the LDP procedures specified in [RFC5036]
>>> MUST
>>> >>>> be
>>> >>>> implemented." I don't know if it's necessary to call special
>>> attention
>>> >>>> to those
>>> >>>> two sections if you have to implement everything anyway.
>>> >>> I agree, but people in the meeting insisted on an explicit mention of
>>> >>> those sections.
>>> >>> Above text is driven by the comments in the meeting.
>>> >>> Let's see if other speak up.
>>> >>> Thanks.
>>> >>> Luca
>>> >>>
>>> >>>> Cheers,
>>> >>>> Andy
>>> >>>>
>>> >>>> On Mon, Jul 27, 2015 at 3:08 PM, Luca Martini <lmartini@cisco.com
>>> >>>> <mailto:lmartini@cisco.com>> wrote:
>>> >>>>
>>> >>>>     Folks,
>>> >>>>
>>> >>>>     Some of you brought up the fact the in the current rfc4447bis
>>> >>>> update
>>> >>>>     document it is not clear that we require a full implementation
>>> of
>>> >>>> the
>>> >>>>     LDP protocol specified in rfc5036.
>>> >>>>
>>> >>>>     In particular the part that is assumed, thought rfc4447bis is
>>> that
>>> >>>> any
>>> >>>>     implementation of this protocol MUST implement responding to
>>> remote
>>> >>>>     label mapping request messages.
>>> >>>>
>>> >>>>     I propose the following update to the text :
>>> >>>>
>>> >>>>     OLD:
>>> >>>>
>>> >>>>     LDP MUST exchange PW FEC label bindings in downstream
>>> unsolicited
>>> >>>>     manner, independent of the negotiated label advertisement mode
>>> of
>>> >>>> the
>>> >>>>     LDP session according to the specifications in specified in
>>> >>>> [RFC7358].
>>> >>>>     LDP's "liberal label retention" mode SHOULD be used.
>>> >>>>
>>> >>>>     NEW:
>>> >>>>
>>> >>>>     LDP MUST exchange PW FEC label bindings in downstream
>>> unsolicited
>>> >>>>     manner, independent of the negotiated label advertisement mode
>>> of
>>> >>>> the
>>> >>>>     LDP session according to the specifications in specified in
>>> >>>> [RFC7358].
>>> >>>>     LDP's "liberal label retention" mode SHOULD be used. However all
>>> >>>> the LDP
>>> >>>>     procedures specified in [RFC5036] MUST be implemented, and
>>> >>>> specifically
>>> >>>>     the procedures in section  3.5.7. "Label Mapping Message", and
>>> >>>> 3.5.8.
>>> >>>>     "Label Request Message".
>>> >>>>
>>> >>>>
>>> >>>>     Does this work ?
>>> >>>>
>>> >>>>     Any other suggestions ?
>>> >>>>
>>> >>>>
>>> >>>>     Thanks.
>>> >>>>
>>> >>>>     Luca
>>> >>>>
>>> >>>>
>>> >>>>     _______________________________________________
>>> >>>>     Pals mailing list
>>> >>>>     Pals@ietf.org <mailto:Pals@ietf.org>
>>> >>>>     https://www.ietf.org/mailman/listinfo/pals
>>> >>>>
>>> >>>>
>>> >>> _______________________________________________
>>> >>> Pals mailing list
>>> >>> Pals@ietf.org
>>> >>> https://www.ietf.org/mailman/listinfo/pals
>>> >> _______________________________________________
>>> >> Pals mailing list
>>> >> Pals@ietf.org
>>> >> https://www.ietf.org/mailman/listinfo/pals
>>> >
>>>
>>>
>>
>