Re: [Pals] Mirja Kühlewind's No Objection on draft-ietf-pals-mpls-tp-dual-homing-coordination-05: (with COMMENT)

["Dongjie (Jimmy)" <[e-mail]>]

Hi Mirja, 

Thanks a lot for your comments. Please see my replies inline.

> -----Original Message-----
> From: Mirja Kühlewind [mailto:[e-mail]]
> Sent: Wednesday, March 01, 2017 12:38 AM
> To: The IESG <[e-mail]>
> Cc: [e-mail]; Stewart Bryant
> <[e-mail]>; [e-mail];
> [e-mail]; [e-mail]
> Subject: Mirja Kühlewind's No Objection on
> draft-ietf-pals-mpls-tp-dual-homing-coordination-05: (with COMMENT)
> 
> Mirja Kühlewind has entered the following ballot position for
> draft-ietf-pals-mpls-tp-dual-homing-coordination-05: No Objection
> 
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> 
> Please refer to https://www.ietf.org/iesg/statement/discuss-criteria.html
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> 
> The document, along with other ballot positions, can be found here:
> https://datatracker.ietf.org/doc/draft-ietf-pals-mpls-tp-dual-homing-coordinati
> on/
> 
> 
> 
> ----------------------------------------------------------------------
> COMMENT:
> ----------------------------------------------------------------------
> 
> Minor mostly editorial comments:
> 
> 1) When I first saw "DHC Code Point" in figure 2, I was slightly confused
> because this doesn't show in the rest of the doc anymore. Maybe rename to
> 'DHC channel type' or use the same term in the text or directly put the value in
> there that will be assigned by IANA.

Thanks for pointing out this. Will change this to "DHC Channel Type" in next revision. 
> 
> 2) 3.1.:"After the transmission of the three messages, the
>    dual-homing PE MUST send the most recently transmitted Dual-Node
>    Switching TLV periodically to the other dual-homing PE on a continual
>    basis using the DHC message."
>    This is only if the protection is active, right?

Yes, the switching TLV is sent periodically after the protection is in active. 

> 
> 3) 3.2.:"Whenever a change of service PW status is detected by a dual-homing
>    PE, it MUST be reflected in the PW Status TLV and sent to the other
>    dual-homing PE immediately using the 3 consecutive DHC messages.
>    This way, both dual-homing PEs have the status of the working and
>    protection PW consistently."
>    Note, it's possible that all three messages get lost. If you want to make
> sure you stay in sync, you need an explicit mechanism for reliability, e.g.
> sending an ack.

The 3 consecutive message mechanism is similar to the mechanism defined in section 4.1 of rfc6378 (MPLS-TP linear protection). It can ensure the state exchange if one or two of the 3 messages get lost. And after the 3 consecutive messages, the message will still be transmitted continuously as defined in section 3.1 of this draft, so the dual-homing PEs would stay in sync. 

Best regards,
Jie