[Ndn-interest] Data comes from another face?

[Ignacio.Solis at parc.com]

Hi folks.

I wanted to bring up a couple of important points to this discussion that have not been mentioned.  Maybe people have already assimilated them so they think they’re obvious, but just in case:

1-  A node should not accept data packets over links/interfaces/faces over which it did not forward an interest.  This is a security risk.

2- NDN may have issues over multiple access links/interfaces/faces where not all nodes can hear each other (non-infrastructure WiFi).

Both of these are true in the basic case. It’s possible that with extra design, protocols or developments that I’m unaware of these can be mitigated/solved.

Nacho


--
Nacho (Ignacio) Solis
Protocol Architect
Principal Scientist
Palo Alto Research Center (PARC)
+1(650)812-4458
Ignacio.Solis at parc.com

On 6/8/15, 9:22 AM, "Muhammad Hosain Abdollahi Sabet" <M.AbdollahiSabet at mail.sbu.ac.ir<mailto:M.AbdollahiSabet at mail.sbu.ac.ir>> wrote:

Junxiao,

Thank you for responding.

>?Infrastructure WiFi is different: at MAC layer, all communications go through the AP (access point).
We could take advantage of this property, and install an NDN stack on the AP that aggregates Interests and caches Data.

?You mean we turn a L2 device (access point) into a wireless router?

 ?
?>?the AP treats the WiFi link as both a multi-access link where packets can be broadcast to all wireless clients, and one point-to-point link to each wireless link.

Does that make any difference? An ap treat a link as a multiple-access or a point-to-point link. I mean in both cases, the ap does the same thing(transmit one copy of a packet). The only difference would be in L2 addressing?, right? Of course there could be difference if using omnidirectional or unidirectional antennas, which could be a big deal facing mobile nodes. But that's out of computer networking scope.

Thanks,
Sabet


-----Original Message-----
From: Junxiao Shi [mailto:shijunxiao at email.arizona.edu]
Sent: Thu 6/4/2015 2:19 AM
To: Muhammad Hosain Abdollahi Sabet
Cc: ndn-interest at lists.cs.ucla.edu<mailto:ndn-interest at lists.cs.ucla.edu>
Subject: RE: [Ndn-interest] Data comes from another face?

Hi Sabet

Ethernet repeater and UDP multicast group are two examples of multi-access
links.

Infrastructure WiFi is different: at MAC layer, all communications go
through the AP (access point).
We could take advantage of this property, and install an NDN stack on the
AP that aggregates Interests and caches Data. Under this design, a wireless
client treats the WiFi link as a point-to-point link to the AP, and the AP
treats the WiFi link as both a multi-access link where packets can be
broadcast to all wireless clients, and one point-to-point link to each
wireless link.

Yours, Junxiao
On May 31, 2015 2:27 PM, "Muhammad Hosain Abdollahi Sabet" <
M.AbdollahiSabet at mail.sbu.ac.ir<mailto:M.AbdollahiSabet at mail.sbu.ac.ir>> wrote:

>  Junxiao,
>
> So in wired nets it would be good old BUS or ethernet HUB networks, which
> is rare these days unless we face lack of switching devices. And in
> wireless nets, generally all of them are multiple-access link, right?
>
> Actually It'very good to see you here by chance. Lately I've been thinking
> on intelligent(self-learning) forwarding and I was counting different
> situations which it would be useful for. Just a couple of hours ago I saw
> your presentation about NDN in LANs at NDNComm and I was like :| "Again,
> I've got here late!", though I had felt the need for such a self-learning
> mechanism in producer mobility. I don't know if still there is a room to
> contribute more in this. As far as I already saw, this NFD in addition to a
> pointer to the chosen output face in PIT, which is available right now,
> lacks some pointer to the chosen FIB entry itself. And of course some
> measures are needed to check efficiency of self-learned chosen faces after
> a while and see if another flooding is needed for choosing possible better
> face.
>
> Thanks,
> Sabet.
>
>
> -----Original Message-----
> From: Junxiao Shi [mailto:shijunxiao at email.arizona.edu
> <shijunxiao at email.arizona.edu<mailto:shijunxiao at email.arizona.edu>>]
> Sent: Sun 5/24/2015 1:48 AM
> To: Muhammad Hosain Abdollahi Sabet
> Cc: ndn-interest at lists.cs.ucla.edu<mailto:ndn-interest at lists.cs.ucla.edu>
> Subject: Re: [Ndn-interest] Data comes from another face?
>
> Hi Sabet
>
> As I understand you question is:
> In a network of NDN nodes where none of the nodes is using broadcast
> strategy, if a node has not forwarded an Interest out of an interface, is
> it possible for this node to receive a Data on this interface?
>
> The answer is YES.
> Think about a multi-access link with 3 hosts P Q R.
>
>    1. Q sends an Interest. P and R receive this Interest,
>    2. P replies with a Data. Q and R receive this Data.
>
> In this scenario, R has not forwarded an Interest to the multi-access link,
> but receives a Data from the multi-access link.
>
> Yours, Junxiao
>
> On Wed, May 20, 2015 at 11:17 AM, Muhammad Hosain Abdollahi Sabet <
> M.AbdollahiSabet at mail.sbu.ac.ir<mailto:M.AbdollahiSabet at mail.sbu.ac.ir>> wrote:
>
> >  Hi,
> > We all know that data packets follow breadcrumbs which interest packets
> > leave behind. And we expect to receive data packets from the same face
> > which interests have already been forwarded to, according to
> correspondent
> > fib entries, right? So, when the second sentence won't happen? I mean a
> > node receive a data packet matching a pit entry, from a face that the
> > interest has not been forwarded to, according to the fib entry. If a node
> > choose to broadcast for forwarding strategy, such a situation happens. I
> > know that. But is there any other condition?
> >
> > Thanks,
> > Sabet
> >
>
>

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