Re: [MEXT] [WGLC] draft-ietf-mext-flow-binding-03

[Hesham Soliman <hesham at elevatemobile.com>]

Yuri,


> 
> After the text:
> 
> "1 Discard.  This value indicates a request to discard all packets
>  in the flow described by the option.  No BIDs are associated with
>  this Action."
> 
> Add the following text:
> 
> "In the case there is no correspondent FID to a particular flow or range of
> flows, which should be discarded, a mobile node MUST install a correspondent
> FID, otherwise error code 136 "FID not found" will be returned by HA.

=> I don't understand what this means. Can you clarify?


  Care 
> should be taken when issuing request for discarding packets as this will lead
> to disrupting applications communication after the "Discard" action was
> applied to selected flows. Implementations may consider notifying impacted
> applications in mobile nodes"

=> This part is clear to me.

Hesham

> 
> 
> 
> Regards
> Yuri
> 
> 
> -----Original Message-----
> From: George Tsirtsis [mailto:tsirtsis at googlemail.com]
> Sent: Friday, October 23, 2009 5:54 PM
> To: Yuri Ismailov
> Cc: Laganier, Julien; mext at ietf.org
> Subject: Re: [MEXT] [WGLC] draft-ietf-mext-flow-binding-03
> 
> Hi Yuri, comments inline.
> 
> On Fri, Oct 23, 2009 at 1:20 PM, Yuri Ismailov <yuri.ismailov at ericsson.com>
> wrote:
>> Hi Goerge,
>> Thanks for the answers,
>> What I did not understand if there will be some clarification text in the
>> draft around "discard" action or all that is obvious and does not require any
>> changes? My comment was that some additional text is needed.
>> 
> 
> GT> I am not yet sure what non-trivial clarification we can provide.
> IMO we do not need to provide any further clarifications on this subject.
> 
>> I do not think your clarification about using FID-PRI is quite clear. The
>> reason is that there is no FID for a particular flow within the range There
>> is only a FID for the whole range of port numbers and/or IP addresses.
>> 
> 
> GT> What prevents you from  creating another FID that is specific for that
> flow?
> 
>> Surprized that disclaimer for n-cast about carefull use is in the text
>> and about disclaimer for "discard" you just say "I do not think there is
>> anything to say here." Still the question is will there be related text?
>> 
> 
> GT> I think the implication of dropping packets is much clearer than
> the implication of n-casting. Dropping packets means the application to which
> the packet is sent will not receive the packet...do we really need to say
> that? On the other hand, receiving N copies of the same packet has some
> implications to TCP....this is also rather obvious for people that know
> TCP...but maybe not everyone does.
> 
>> Regards
>> Yuri
>> 
>> 
>> -----Original Message-----
>> From: George Tsirtsis [mailto:tsirtsis at googlemail.com]
>> Sent: Friday, October 23, 2009 11:08 AM
>> To: Yuri Ismailov
>> Cc: Laganier, Julien; mext at ietf.org
>> Subject: Re: [MEXT] [WGLC] draft-ietf-mext-flow-binding-03
>> 
>> Hi Yuri,
>> 
>> Comments inline...
>> 
>> On Tue, Oct 20, 2009 at 8:55 AM, Yuri Ismailov <yuri.ismailov at ericsson.com>
>> wrote:
>>> Hi,
>>> after re-reading the draft come up with the comment on "Discard"
>>> action in "Flow Identification Mobility Option"
>>> I suggest either to extend the paragraph in the section 4.2 or add a
>>> separate subsection clarifying behavior of MN and HA before and after
>>> the "Discard" action was issued by MN.
>>> 
>>> Below are the issues which are proposed to be addressed in the text.
>>> 
>>> 1.The case when installed FID represent ranges of port numbers and IP
>>> addresses. If MN decides to discard a particular flow within the
>>> range then before that a correspondent FID should be installed in the HA.
>>> Otherwise
>>> "136 FID not found" will be returned from HA.
>>> 
>> 
>> GT> If the MN wants to discard a particular flow within a range of
>> previously registered flows, it needs to either split the range it two parts,
>> or even better, use a higher FID-PRI for the  discard flow so that packets
>> get matched against it before they get matched against the range.
>> 
>>> 2. Specify the time interval for how long time the "Discard" state
>>> will be active in HA. This is necessary because there is no
>>> "un-discard" message sent from MN.
>>> 
>> 
>> GT> Flow bindings share the same lifetime with the BU. There is no
>> flow binding-specific lifetime. If an MN wants to remove a flow binding it
>> sends a BU which does not include the corresponding FID.
>> 
>>> 3. Add a disclaimer that for some protocols, like TCP, "Discard"
>>> action may lead to hanging up the connection at CN and should be used
>>> responsibly.
>>> 
>> 
>> GT> Discarding packets will drop connections....yes...I do not think
>> there is anything to say here.
>> 
>>> 
>>> Regards
>>> Yuri
>>> 
>>> 
>>> _______________________________________________
>>> MEXT mailing list
>>> MEXT at ietf.org
>>> https://www.ietf.org/mailman/listinfo/mext
>>> 
>>> 
>> 
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