RE: [DNA] Considerations for DNA Schemes with multiple Interface andLayer 2 Technologies

[YGHONG <yghong@etri.re.kr>]

 Dear JinHyeock..

 Because I am not a specialist about CDMA, I can be wrong in some points.
 As my understanding (with discussion with other CDMA specialists), 
it is possible for a host to distinguish the IP packets from the old
link-layer connection FROM the ones
from the new link-layer connection. The reason is that a host in CDMA can
have two link-layer connections 
during handover between base stations. One link-layer connection is for an
old base station, the other link-layer
connection is for a new base station. When handover happens and by using
make-before-break, a host can have 
the ability to distinguish the IP packets. (Actually, current IPv4 based
CDMA packet service in Korea, unfortunately
only supports break-before-make(hard handover) because there are no needs
for make-before-break(soft handover) )
 So, if this situation is valuable for DNA schemes,  we can ask CDMA
operators to support make-before-break in 
IPv6 based CDMA packet service. 

 But, if two(old and new) base stations are connected to different PDSN
(Packet Data Serving Node, similar to router), 
during handover between base stations, an old PPP connection between the
host and an old PDSN is disconnected 
and then a new PPP connection between the host and a new PDSN is connected.
In this case, only break-before-make is used.

 Yong-Geun..


 > -----Original Message-----
> From: JinHyeock Choi [mailto:jinchoe@gmail.com] 
> Sent: Saturday, October 23, 2004 1:55 AM
> To: greg.daley@eng.monash.edu.au
> Cc: YGHONG; dna@eng.monash.edu.au; ???; ???
> Subject: Re: [DNA] Considerations for DNA Schemes with 
> multiple Interface and Layer 2 Technologies
> 
> 
> Dear Yong-Geun
> 
> I think that the case 3.2, 'Single interface with Make before Break'
> will affect DNA solution design. I agree that we are not 
> familiar with this case, so it would be of much help, if you 
> elaborate the below with more detail. 
> 
>      We think that we are not familiar with this case. But in 
> CDMA[7], a
>      mobile station can access two or more different base stations
>      simultaneously. In this case, a host can make a new link-layer
>      connection before an old link-layer connection is torn down.
> 
> Especially I wonder whether it's possible for a host to 
> distinguish the IP packets from the old link-layer connection 
> FROM the ones from the new link-layer connection.  
> 
 

> However, it's not clear to me the relationship between 'DNA schemes' 
> and 'multiple interfaces' from Case 3.3 & 3.4 description. I 
> still can't see how multiple interfaces would affect DNA 
> schemes substantially. Kindly elaborate this more. 
> 
> Thanks for your kind consideration. 
> 
> Best Regards
> 
> JinHyeock
>