Re: [Mip6] [issue93] Payload Qualifiers when using IPv4-UDP transportfor both IPv4 and IPv6 payloads

Hesham Soliman wrote:
> 
>> Version field can be used to distinguish that. But, when a packet
>> is encapsulated in any application header, it needs to be wrapped
>> in a TLV format. Example: RFC-3519. If there is no wrapper,
>> application would not even know the size of that packet, or the
>> type of the packet, unless its derived from the IP header. That
>> adds some complexity w.r.t the way applications use the socket
>> interface ..options etc. Having a wrapper would be usefull. The
>> normal encapsulation modes in L3 such as IP/IP, IPv6/IPv6, GRE, all
>> have the type field and so when we wrap a packet in L4, we need an
>> identifier some where, IMO.
> 
> => I know the following question is not necessarily the crux of your
> issue but does anyone implement MIPv6 as an application? I know it's
> possible to do that but no one seemed to make that choice to my
> knowledge, but I could be wrong.
> 
> I'd love to hear what others think, I think it's a good point to
> discuss.

Sorry for replying late on this.  I got redirected here from NETLMM WG.

I deal with three types of mip6 implementations: kernel exclusively, app
exclusively and mixed.

My initial was kernel-exclusively.  Then people said it's complicated.
Then some app-exclusively mip6 implementation had some advantages but
turned out to not send BU upon handover because the ongoing audio/video
stream was taking too many resources.

Just to say that it depends on what kind of environment one works on, 
and that there _are_ advantages to do kernel only.

Alex

> 
> Hesham
> 
>> 
>> Thanks Sri
>> 
>> 
>> On Wed, 28 Feb 2007, Hesham Soliman wrote:
>> 
>>> Hi Sri,
>>> 
>>> Why can't the receiver do the switch on the version field? I
>>> mean, how does the receiver of any encapsulated packet
>> know the version of
>>> the inner header?
>>> 
>>> Hesham
>>> 
>>>> -----Original Message----- From: Sri Gundavelli
>>>> [mailto:tracker-mip6@mip4.org] Sent: Wednesday, February 28,
>>>> 2007 8:38 AM To: mip6@ietf.org Subject: [Mip6] [issue93]
>>>> Payload Qualifiers when using IPv4-UDP transportfor both IPv4
>>>> and IPv6 payloads
>>>> 
>>>> 
>>>> New submission from Sri Gundavelli <sgundave@cisco.com>:
>>>> 
>>>> Reference to section 4.3.1 and 4.4.1.
>>>> 
>>>> For the IPv4 transport and with NAT in path, the opaque 
>>>> encapsulation mode of IPv4-UDP for both IPv4 and IPv6 payload
>>>> packets i.e IPv6/IPv4-UDP or IPv4/IPv4-UDP is being recommended
>>>> by the draft. With out a payload qualifier in the UDP header, I
>>>> wonder how the tunnel peer handles the packet after
>>>> decapsulation ? How would it know, if it is an IPv4 payload
>>>> packet or an IPv6 packet ? Do you expect some packet inspection
>>>> after decapsulation ?
>>>> 
>>>> One option is to have thin header such as the MIP Tunnel Data
>>>> Message from RFC-3519, as suggested by Kent Leung.
>>>> 
>>>> 
>>>> MIP Tunnel Data Message
>>>> 
>>>> 0                   1                   2                   3 0
>>>> 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
>> 6 7 8 9 0 1
>>>> 
>> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
>>>> |     Type      |  Next Header  |           Reserved
>> |
>>>> 
>> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
>>>> 
>>>> 
>>>> We want a quick resolution on this. 
>>>> draft-sgundave-mip6-proxymip6-02.txt has normative reference to
>>>> the DSMIP6 spec.
>>>> 
>>>> Thanks Sri
>>>> 
>>>> ---------- category: Technical draft:
>>>> draft-ietf-mip6-nemo-v4traversal messages: 330 nosy: sri 
>>>> priority: Must fix status: No discussion title: Payload
>>>> Qualifiers when using IPv4-UDP transport for both IPv4 and IPv6
>>>> payloads
>>>> 
>>>> _________________________________________________ Mip6 issue
>>>> tracker <tracker-mip6@mip4.org> 
>>>> <http://www.mip4.org/issues/tracker/mip6/issue93> 
>>>> _________________________________________________
>>>> 
>>>> _______________________________________________ Mip6 mailing
>>>> list Mip6@ietf.org https://www1.ietf.org/mailman/listinfo/mip6
>>>> 
>>> 
>>> 
>>> 
>>> _______________________________________________ Mip6 mailing list
>>>  Mip6@ietf.org https://www1.ietf.org/mailman/listinfo/mip6
>>> 
>> 
> 
> 
> 
> _______________________________________________ Mip6 mailing list 
> Mip6@ietf.org https://www1.ietf.org/mailman/listinfo/mip6
> 

______________________________________________________________________
This email has been scanned by the MessageLabs Email Security System.
For more information please visit http://www.messagelabs.com/email 
______________________________________________________________________

_______________________________________________
Mip6 mailing list
Mip6@ietf.org
https://www1.ietf.org/mailman/listinfo/mip6