Re: [pcp] I-D Action: draft-vinapamula-flow-ha-03.txt

["Tirumaleswar Reddy (tireddy)" <[e-mail]>]

> -----Original Message-----
> From: [e-mail]
> [mailto:[e-mail]]
> Sent: Friday, September 19, 2014 11:38 AM
> To: Tirumaleswar Reddy (tireddy); [e-mail]; [e-mail]
> Subject: RE: I-D Action: draft-vinapamula-flow-ha-03.txt
> 
> Hi Tiru,
> 
> Please see inline.
> 
> Cheers,
> Med
> 
> >-----Message d'origine-----
> >De : Tirumaleswar Reddy (tireddy) [mailto:[e-mail]] Envoyé :
> >jeudi 18 septembre 2014 17:18 À : BOUCADAIR Mohamed IMT/OLN;
> >[e-mail]; [e-mail] Objet : RE: I-D Action:
> >draft-vinapamula-flow-ha-03.txt
> >
> >> -----Original Message-----
> >> From: [e-mail]
> >> [mailto:[e-mail]]
> >> Sent: Thursday, September 18, 2014 11:57 AM
> >> To: Tirumaleswar Reddy (tireddy); [e-mail]; [e-mail]
> >> Subject: RE: I-D Action: draft-vinapamula-flow-ha-03.txt
> >>
> >> Hi Tiru,
> >>
> >> There are two approaches to address this issue:
> >> (1) consider a unified priority level: that is all flows associated
> >> with
> >the option
> >> in the draft should be "processed" equally.
> >> (2) add another level of granularity among flows that are associated
> >> with
> >the
> >> option in this draft.
> >>
> >> The current version of the I-D argues that adding another level of
> >granularity
> >> to signal a priority level (i.e., approach (2)) may not be that
> >> helpful
> >because
> >> applications will be tempted to systematically set the priority level
> >> to
> >the
> >> highest value in order to increase the chance to have the
> >> corresponding
> >flow
> >> check-pointed/protected.
> >
> >I can think of two to three ways to address this problem 1)Applications
> >with required authorization can only signal that it's a high priority
> >flow.
> >2)End User with the help of a web-portal let's say provided by Home
> >Gateway or ISP can re-arrange priorities of flows. Applications like
> >uTorrent already provide UI so that user can assign priorities for
> >different file downloads.
> >3)Just like various good background applications use LEDBAT to limit
> >congestion, we can except that such applications in future will
> >explicitly signal that it's a low priority flow.
> >
> 
> [Med] Do you mean PCP messages will be modified in path?

No, I meant there will be some applications that will declare that they have low-priority flows just like applications that declare  that HA is not required.

> 
> >>
> >> Wouldn't (1) be sufficient to address the case you mentioned in your
> >> message?
> >
> >I don't think it is sufficient, it does not provide relative priority.
> 
> [Med] Do these flows require check-pointing too? Or you only care about
> prioritizing these flows during congestion events?

These flows could care about both check-pointing and prioritization or care about only one of them.

-Tiru

>