Subject: RE: [DNA] Revised FRD (Fast Router Discovery) I-D

From: "Tero Kauppinen (JO/LMF)" <[email-masked]>
Date: Tue, 19 Jul 2005 13:38:24 +0200

Hi JinHyeock,

Just a couple of quick questions...

Should entries in the cache suppose to have the lifetime stated in an
RA?

I guess PoA uses sending router's source address to index entries in the
cache, i.e. if a router sends an updated RA, PoA finds the old entry by
using the source address (or source link layer address in the option
field).

--
Tero

---

From: JinHyeock Choi <[email-masked]>
Date: Wed, 20 Jul 2005 12:08:05 +0900

Dear Tero

Thanks for comments. 

FRD is actually a schema, a collection of schemes. With the 
combination of various sub-components, we can implement 
it in different ways. 

I assume your question concern mostly about RA Proxying with 
Scanning. Am I right? 

> Should entries in the cache suppose to have the lifetime stated in an

No. We don't think it's desirable for PoA to modify an RA, unless
it gets permission from AR. 

> using the source address (or source link layer address in the option

Right now, we design the scheme in the simplest way and PoA doesn't 
manage index entries. 

Assume there are two routers on a link, AR1 and AR2. First AR1 
sends RA1 and PoA caches it. Afterwards AR2 sends RA2, then 
PoA substitutes its cached RA with RA2. This doesn't affect DNA 
performance as long as both RA1 and RA2 can properly indicate
link identity, i.e. RA optimized for DNA. 

Also we implemented FRD with with 802.11 AP and it works 
as below. 

1. We implemented FRD module on drives modules of
  netgear AP.

2. FRD module caches a multicast RA
  (multicast in IP point of view)

3. When an MN is attached, FRD module extracts the MN's MAC
  address from the L2 association request message.

4. FRD module combines the MN's MAC address with the cached RA
  to make an unicast L2 frame.
  (But the L2 frame contains a multicast RA.)

5. FRD module sends the unicast L2 frame
  (with the cached multicast RA) to the MN.

6. The MN receives the cached RA (in the unicast L2 frame).
   in average 1.3 ms. 

Thanks for your kind consideration. 

Best Regards

JinHyeock