Re: [netext] #4: Logical interface support: Point to point links

[Sri Gundavelli <[e-mail]>]

Julien:

We all agree, the link model is still P2P. All I'm saying, we should not
classify P2P vs Non-P2P, based on the access technology type. I can build
P2P link on an IPsec tunnel, 802.11 access, or a GRE tunnel. We just require
P2P communication semantics, if we specify more that this, it will be an
over specification. Lets work out the text for this.


Sri



On 3/15/11 3:51 PM, "Julien Laganier" <[e-mail]> wrote:

> Sri:
> 
> I am going to repeat it once again: you are equating advertizing or
> per-MN subnet prefix to a point-to-point link, but these are two
> different things, thus I am saying that we have a problem as 5213 is
> limited to support of point-to-point links.
> 
> --julien
> 
> 2011/3/14 Sri Gundavelli <[e-mail]>:
>> Julien:
>> 
>> Lets see, what is the violation here ?
>> 
>> - We are stating the logical interface appears to the applications as an
>> interface attached to a shared link. For the simple reason, that we have
>> multiple neighbors on different network segments attached through different
>> sub-interface of that logical interface. We don't have a single
>> neighbor/MAG.
>> 
>> - "Underneath the logical interface ...", there are sub-interfaces which may
>> be very well attached to different p2p links. As long as the network has the
>> semantics to send a RA with PIO, exclusively to this node, no other node on
>> that access link can receive that Prefix set, we are confirming to 5213 link
>> model. From any of the MAG's perspective, attached to any of the access
>> links, it can still be kept as a p2p link
>> 
>> - Exposing the logical interface as a shared link to the applications on the
>> *mobile node*, is not violating 5213 principles. The path chosen for a
>> packet through a sub-interface can be still a p2p link and the rules of
>> link-layer resolution of the peer, or adding l2 headers skipping l2
>> resolution, is still the approach in use.
>> 
>> 
>> 
>> 
>> Sri
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> On 3/14/11 5:20 PM, "Julien Laganier" <[e-mail]> wrote:
>> 
>>> Sri -
>>> 
>>> 5213 supports only PtP links thus I do not understand how the
>>> following resolution resolves anything. Please clarify what is the
>>> issue you' re addressing and how this is addressing it.
>>> 
>>> --julien
>>> 
>>> On Mon, Mar 14, 2011 at 4:24 PM, Sri Gundavelli <[e-mail]> wrote:
>>>>> #4: Logical interface support: Point to point links
>>>> 
>>>>  Clarify the use and
>>>>> behavior of the logical interface on PtP links.
>>>> 
>>>> 
>>>> Folks: Again, reflecting the team's contributions on this topic, the
>>>> authors
>>>> of this document have discussed this and resolve it with the following
>>>> text.
>>>> The key points we tried to reflect are around that the logical interface
>>>> appears to the application as a shared link. There were thoughts around
>>>> making it appear like a p2p link, given that there are multiple neighbors
>>>> on
>>>> each sub interface, this choice appears reasonable. With respect to how a
>>>> packet is transmitted, is still based on the chosen link model at each sub
>>>> interface level. Let us know, if you see any issues with it. This is proven
>>>> based on the multiple implementations from some of the co-authors of this
>>>> doc.
>>>> 
>>>> 
>>>> 
>>>> 
>>>> ---
>>>> 6.3.  Supported Link models for a logical interface
>>>> 
>>>>  The sub-interfaces of a logical interface can be bound to a point-to-
>>>>   point or a shared link (Example: LTE and WLAN).  The logical
>>>>   interface appears as a shared-link to the applications, and adapts to
>>>>   the link model of the sub-interface for packet communication.  For
>>>>   example, when transmitting a packet on a sub-interface which is
>>>>   attached to a p2p link, the transmission conforms to the p2p link
>>>>   model and when transmitting on a sub-interface attached to a shared
>>>>   link, the transmission conforms to the shared link model.
>>>> 
>>>>   Based on the link to which the sub-interface is attached to, the
>>>>   layer-2 resolutions may or may not be needed.  If the interface is
>>>>   bound to a P2P link with PPP running, there will not be any link-
>>>>   layer resolutions in the form of ARP/ND messages.  However, if the
>>>>   interface is bound to a shared link such as Ethernet, there will be
>>>>   ND resolutions.  The logical interface implementation has to maintain
>>>>   the required link model and the associated state for each sub-
>>>>   interface.
>>>> --
>>>> 
>>>> 
>>>> 
>>>> 
>>>> On 3/3/11 9:17 AM, "netext issue tracker" <[e-mail]>
>>>> wrote:
>>>> 
>>>>> #4: Logical interface support: Point to point links
>>>> 
>>>>  Clarify the use and
>>>>> behavior of the logical interface on PtP links.
>>>> 
>>>> --
>>>>> 
>>>> 
---------------------------------------+----------------------------------->>>>
-
>>>> 
>>>>> Reporter:  basavaraj.patil@Š          |       Owner:  telemaco.melia@Š
>>>>> 
>>>>     Type:  defect                     |      Status:  new
>>>>> 
>>>>  Priority:  major                      |   Milestone:
>>>>> 
>>>> Component:  logical-interface-support  |     Version:
>>>>> 
>>>>  Severity:  -                          |    Keywords:
>>>>> 
>>>> 
---------------------------------------+----------------------------------->>>>
-
>>>> 
>>>>> 
>>>> Ticket URL: <http://trac.tools.ietf.org/wg/netext/trac/ticket/4>
>>>> netext
>>>>> <http://tools.ietf.org/netext/>
>>>> 
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