Subject: [DNA] draft-ietf-dna-frd-00.txt clarification for RA trigger

From: "Kent Leung (kleung)" <[email-masked]>
Date: Thu, 17 Nov 2005 11:53:13 -0800

Hi folks.  Just joined the alias.  Hope this has not been discussed
already.
 
This section says that the PoA can send RS to trigger RA from the AR.
What's not clear is what source link-layer address is put into the
TSLLAO option (maybe it's implicit)?  I'm assuming that the source
link-layer address of the RS is the PoA, and the address in TSLLAO is
the host so the RA can be unicasted directly to the host.
3.1  RA Triggering
   There are two ways for such a remote Link Up event notification.  We
   may use the MIES (Media Independent Event Service) defined in IEEE
   802.21 [21] or RS with TSLLAO (Tentative Source Link-Layer Address
   Option) [14].
In the 802.11 example below, no mention of RS method.  In this case, the
AP will send RS with source MAC 
address being AP's and the TSLLAO containing the host.

5.2.1  802.11

   In 802.11 Wireless LAN technology, when a new host arrives at an
   AP(Access Point), it should associate with the AP.  The host sends an
   Association Request Message with its MAC address.  Then the AP sends
   an Association Response Message to grant association.

   As soon as association is made, the AP sends a cached RA to the host
   in an unicast 802.11 frame with the MAC address from the Association
   Request message.  The host receives the unicast RA just after
   association is made, which is the earliest possible time in current
   standard.

What is the status of  draft-daley-ipv6-tsllao-02.txt?  Is this being
adopted 
in IPv6 or DNA WG?
 
Thanks for clarifying.
 
Kent

---

From: Greg Daley <[email-masked]>
Date: Fri, 18 Nov 2005 10:28:59 +1100

Hi Kent,

Kent Leung (kleung) wrote:
>  
> Hi folks.  Just joined the alias.  Hope this has not been discussed already.
>  

Yes, I think that this is the intention.

 > AP will send RS with source MAC address being AP's and the
 > TSLLAO containing the host.
> 

Yes, I think so.

> What is the status of  draft-daley-ipv6-tsllao-02.txt?
 > Is this being adopted in IPv6 or DNA WG?

It may be adopted in DNA working group.
That seemed to be the feel of the room at the session.

That said, the draft wasn't presented in a regular way
(not advertised in the agenda, and I was actually surprised
that Suresh asked me to make a presentation on-the-fly).
So we definitely need to make an on-list consensus call
as to whether the document should be adopted in DNA as a
WG document.

Greg

---

From: JinHyeock Choi <[email-masked]>
Date: Fri, 18 Nov 2005 17:29:50 +0900

Dear Kent

> What's not clear is what source link-layer address is put into the TSLLAO
> option (maybe it's implicit)?  I'm assuming that the source link-layer
> address of the RS is the PoA, and the address in TSLLAO is the host so the
> RA can be unicasted directly to the host.

We intended that the RS (sent by PoA) carries
1) unspecified source address
2) the host's MAC address in TSLLAO.

It's not our intention that the RS carries PoA's MAC address in SLLAO.
We are worried that it might bring confusion if a packet carries
different MAC addresses in TSLLAO and SLLAO.

>  There are two ways for such a remote Link Up event notification. We
 may
> use the MIES (Media Independent Event Service) defined in IEEE
 802.21 [21]
> or RS with TSLLAO (Tentative Source Link-Layer Address
 Option) [14].
> In the 802.11 example below, no mention of RS method. In this case, the AP
> will send RS with source MAC

Similarly in this case, the AP will sends an RS
1) with unspecified source address
2) with the host's MAC address in TSLLAO.
3) without AP's MAC address

Main difference between MN soliciting and AP soliciting is that, with
the latter, we can realize a scheme (similar to Hash based FastRA) in
a simpler way.

We can assume that an AP knows all the ARs in a link. So AP can send
UNICAST RS (to remove random delay) and solicit ARs in turns (for load
balancing).

When a new host is attached to the AP, AP can sends an unicast RS to a chosen AR
1) with unspecified source address
2) with the host's MAC address in TSLLAO.

Upon receiving the unicast RS, the AR can send an RA immediately
(because it is solicited in unicast). in unicast (using TSLLAO)

Also AP take turns to solicit ARs, such as this time AR1 next time AR2
to achieve load balancing.

Thanks in advance for your kind consideration.

Best Regards

JinHyeock