Re: [pcp] FW: New Version Notification for draft-vinapamula-flow-ha-01.txt

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

Hi Suresh,

Comments:

[1] What is the reason for updating the reserved field in the PCP Common Request Packet Format ?
A new PCP option can also be defined to signal if it's a critical flow or not.

[1b] It may help the client to know if the flow is check pointed or not, this way the client can make a decision to prioritize the flows accordingly when multiple interfaces with associated PCP servers are involved.

[1c] Success or fail response ((e.g. Quota exceeded) from PCP server can also help the client to remove check pointing for some of the existing flows so as to check point new flows.

[2] This document describes a mechanism for a host to signal various
   network functions' High Availability (HA) module to checkpoint
   interested connections through PCP.

Comment> The above line is not clear. 

[3]   Internet service continuity is critical in service provider
        environment.  To achieve this, most service providers have active-
        backup systems.

Comment> Enterprise networks also typically deploy Active-Standby. 

[4] For service continuity of those connections on backup
   when active fail, that corresponding state had to be checkpointed on
   the backup.

Nit> Replace "fail" with "fails"

[5]   Typically, this is addressed by identifying long lived connections
        and checkpointing state of only those connections that lived long
         enough, to the backup for service continuity.

Comment> You may want to add that identification is also done by DPI, which fails with encrypted traffic.

[6]   2.  A connection may not be long lived but critical like shorter
       phone conversations.

Comment> Replace "phone conversation" with "VOIP conversation"

[7]     3.  Similarly not every long lived connection need to be critical,
       say a free-service connection of a hosted service need not be
       checkpointed while a paid-service connection has to be
       checkpointed.

Comment> Why would the application client differentiate and not signal that it's a critical flow in both the cases. Are you envisioning that the application client software makes this decision internally or it involves human intervention from some UI to signal to the network that it's a critical flow.

[8] How would this work when PCP authentication is used ?
(I mean will authentication related info be also check pointed or client will have to authenticate afresh when backup becomes active and other related issues.)

[9]   1.  Disruption in a phone connection is not desired.  Application
       that is initiating a phone connection MUST mark connection HA bit
       in the header, while initiating a PCP request for checkpointing.

Comment> Are you referring to VoIP signaling connection ?

[10]   2.  Similarly disruption in media streaming is not desired.  A user
       hosting a media service, MUST mark HA bit in the header while
       initiating a mapping request, and MAY mark connection associated
       with that mapping, depending on whether the connection is from a
       paid subscriber or from a free subscriber through a PEER request.
       So checkpointing mapping doesn't result in auto checkpointing of
       connections, as it gives flexibility to the end user to pick
       specific connections only to checkpoint.

Comment> I am not sure why this distinction is required b/w free and paid VoIP calls, free call could also be an emergency call or high-priority call.

6.   In conjunction with NAT, other network functions that MAY maintain
   state for each conneciton such as Stateful Firewall, IPSec, Load
   balancing etc..., MAY register to PCP server, and MAY be triggered
   for checkpointing respective state of that connection.

Comment1> Are there stateless firewalls ?
Comment 2> I did not understand this draft usage with load balancers and IPSec.

Cheers,
-Tiru


> 
> On 6/13/14 4:19 PM, "Suresh Kumar Vinapamula Venkata"
> <[e-mail]> wrote:
> 
> >Hi
> >
> >This new version of draft address review comments received on the
> >previous version. Kindly review.
> >Sorry for the delay.
> >
> >Thanks
> >Suresh
> >
> >On 6/13/14 4:14 PM, "[e-mail]"
> ><[e-mail]>
> >wrote:
> >
> >>
> >>A new version of I-D, draft-vinapamula-flow-ha-01.txt has been
> >>successfully submitted by Suresh Vinapamula and posted to the IETF
> >>repository.
> >>
> >>Name:		draft-vinapamula-flow-ha
> >>Revision:	01
> >>Title:		Flow high availability through PCP
> >>Document date:	2014-06-13
> >>Group:		Individual Submission
> >>Pages:		6
> >>URL:
> >>http://www.ietf.org/internet-drafts/draft-vinapamula-flow-ha-01.txt
> >>Status:
> >>https://datatracker.ietf.org/doc/draft-vinapamula-flow-ha/
> >>Htmlized:       http://tools.ietf.org/html/draft-vinapamula-flow-ha-01
> >>Diff:
> >>http://www.ietf.org/rfcdiff?url2=draft-vinapamula-flow-ha-01
> >>
> >>Abstract:
> >>   This document describes a mechanism for a host to signal various
> >>   network functions' High Availability (HA) module to checkpoint
> >>   interested connections through PCP.
> >>
> >>
> >>
> >>
> >>
> >>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.
> >>
> >>The IETF Secretariat
> >>
> >
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