Subject: RE: [Mip6] FW: Internal WG Review: Recharter ofMobility for IPv4(mip4)

From: "Soliman, Hesham" <[email-masked]>
Date: Wed, 21 Jun 2006 05:36:49 -0700

> >> In CASEI and CASEII, if we assume HA must support both mip4 and
 > >> mip6 protocols, it means that if the operator wants to deploy ipv6
 > >> network, the ipv6 network must support ipv4 protocol.
 > > 
 > > => Sorry, you keep repeating that the operator must 
 > support MIPv6 and
 > >  MIPv4 and I already explained that the whole point of DSMIP is to
 > > avoid that. So your concern is not applicable to dsmip solutions. A
 > > dual stack is certainly needed if you want to support IPv4 and IPv6
 > > home addresses. If you don't, then don't support a dual stack
 > > network, dsmip allows for that too.
 > 
 > Using DS-MIPv6 requires the HA to run both IPv4 and IPv6.  
 > This does not
 > scale to an IPv6-only HA infrastructure.

=> Huh? what do you mean by "scale" ?
Needless to say there won't be much IPv6-only networks around in the
near term.

 > 
 > >> If the operator runs only ipv6 protocol in one home network, to
 > >> support dsmip6, the operator must deploy ipv4 protocol in that
 > >> network  I think it is impossible because ipv4 address is a scarce
 > >> resource,and operators may not be able to assign every HA  an ipv4
 > >> address pool.
 > > 
 > > => They would do it with private addresses, and they will suffer 
 > > (hopefully not for too long) the same problems associated with
 > > private addresses that we suffer today.
 > 
 > I don't get the message here... Does this mean that 
 > deploying DS-MIPv6
 > on an IPv6 HA infrastructure requires IPv4 _and_ a NAT?

=> No it means that deploying a dual stack network will most likely
imply the use of private IPv4 addresses and NATs. At least in large
networks. 

Hesham

_______________________________________________
Mip6 mailing list
[email-masked]
https://www1.ietf.org/mailman/listinfo/mip6

---

From: Alexandru Petrescu <[email-masked]>
Date: Wed, 21 Jun 2006 15:11:56 +0200

Soliman, Hesham wrote:
>>>>  mip6 protocols, it means that if the operator wants to deploy 
>>>> ipv6 network, the ipv6 network must support ipv4 protocol.
>>> 
>>>  avoid that. So your concern is not applicable to dsmip 
>>> solutions. A dual stack is certainly needed if you want to 
>>> support IPv4 and IPv6 home addresses. If you don't, then don't 
>>> support a dual stack network, dsmip allows for that too.
>> 
>> Using DS-MIPv6 requires the HA to run both IPv4 and IPv6. This does
>>  not scale to an IPv6-only HA infrastructure.
> 
> => Huh? what do you mean by "scale"?

I mean an IPv6-only network is very large.  If only its borders support
IPv4 and IPv6 then all routers inside can't be HAs whose nodes attach to
IPv4-only networks.

> Needless to say there won't be much IPv6-only networks around in the

There are currently more IPv6-only routers deployed than MIP6 MNs.

An operator can't hold back the migration of its infrastructure network
to IPv6, just because some other operators offer IPv4-only access.  Or,
DS-MIPv6 is just that.  An operator running DS-MIP6 for its MNs can't
operate an IPv6-only infra if its MNs connect to another operator's
IPv4-only network.

>> I don't get the message here... Does this mean that deploying 
>> DS-MIPv6 on an IPv6 HA infrastructure requires IPv4 _and_ a NAT?
> 

Ok, got it.

It is still possible to have a MIP6 MN with an IPv4 stack, connecting to
an IPv4-only network, use NAT traversal, and its operator not be forced
to dual-stack all the HAs, just a "gateway" farm.  And that is not
DS-MIPv6, and no NAT.

Alex

---

From: "Soliman, Hesham" <[email-masked]>
Date: Wed, 21 Jun 2006 06:31:56 -0700

> IPv4 and IPv6 then all routers inside can't be HAs whose 

=> Please tell me exactly what the scalability concerns are. I can't
follow the above.

 > to dual-stack all the HAs, just a "gateway" farm.  And that is not

=> You're right that's not DSMIPv6. We chose a different path, which
achieves the same result. Instead of requiring a "gateway farm" we reuse
the HA. 

Hesham

---

From: Alexandru Petrescu <[email-masked]>
Date: Wed, 21 Jun 2006 15:37:38 +0200

Soliman, Hesham wrote:
>> I mean an IPv6-only network is very large.  If only its borders 
>> support IPv4 and IPv6 then all routers inside can't be HAs whose 
>> nodes attach to IPv4-only networks.
> 

With DS-MIPv6, the size of the operator's IPv6 infra can not grow larger
("scale") than what the IPv4 protocol allows.  Does that makes sense?

>> It is still possible to have a MIP6 MN with an IPv4 stack, 
>> connecting to an IPv4-only network, use NAT traversal, and its 
>> operator not be forced to dual-stack all the HAs, just a "gateway"
>>  farm.  And that is not DS-MIPv6, and no NAT.
> 
> achieves the same result. Instead of requiring a "gateway farm" we 
> reuse the HA.

I agree, DS-MIPv6 makes sense in initial deployments but is not a
long-term migration path because holds back the operator from deploying
an IPv6-only infra.

Alex

---

From: "Tsirtsis, George" <[email-masked]>
Date: Wed, 21 Jun 2006 06:58:08 -0700

I have nothing against gateway farms and they can certainly used like
that. Problem is that the end node needs to either be preconfigured with
them or have yet another way to discover them, a way to create a
security association with them, a way to deal with failures etc etc.
Re-using the HAs makes some sense in that respect.

> -----Original Message-----
> From: Soliman, Hesham [mailto:[email-masked]]
> Sent: Wednesday, June 21, 2006 9:32 AM
> To: Alexandru Petrescu
> Cc: [email-masked]
> Subject: RE: [Mip6] FW: Internal WG Review: Recharter ofMobility for
> IPv4(mip4)
> 
> 
> 
>  > connecting to
reuse

---

From: Alexandru Petrescu <[email-masked]>
Date: Wed, 21 Jun 2006 16:13:48 +0200

Tsirtsis, George wrote:
>  that. Problem is that the end node needs to either be preconfigured
> with them or have yet another way to discover them, a way to create a

"Gateway" farms can simply be 6to4 Relays.  They have their anycast
discovery mechanisms.  However doesn't work behind NAT.  "Gateway" farms
can be Teredo Servers, or  STUN Servers.  These don't have a
over-the-Internet discovery mechanisms, they should be pre-configured on
the MNs.

But I don't see what's the complain about.

DS-MIPv6 can't "discover" its HAs either, DHAAD is for IPv6 only.

IPv6 split bootstrapping doesn't work over IPv4.

Alex

---

From: "Tsirtsis, George" <[email-masked]>
Date: Wed, 21 Jun 2006 07:30:30 -0700

There is no complaint. I am simply pointing out that if you use HAs and
a Gateway (of whatever form) you have to discover, manage and secure two
entities instead of one. 

> From: Alexandru Petrescu [mailto:[email-masked]]
> Sent: Wednesday, June 21, 2006 10:14 AM
> To: Tsirtsis, George
> Cc: Soliman, Hesham; [email-masked]
> Subject: Re: [Mip6] FW: Internal WG Review: Recharter ofMobility for
> IPv4(mip4)
> 
> Tsirtsis, George wrote:

---

From: Alexandru Petrescu <[email-masked]>
Date: Wed, 21 Jun 2006 16:32:34 +0200

> a Gateway (of whatever form) you have to discover, manage and secure two

Ok, just to say that DS-MIPv6 also has to discover its HAs, currently 
DS-MIPv6 MN can't discover its HA.

Alex

---

From: "Tsirtsis, George" <[email-masked]>
Date: Wed, 21 Jun 2006 07:35:09 -0700

Nobody is perfect :-)

> Sent: Wednesday, June 21, 2006 10:33 AM
> To: Tsirtsis, George

---

From: "Soliman, Hesham" <[email-masked]>
Date: Wed, 21 Jun 2006 07:42:45 -0700

Alex, please read the draft again....sigh 

 > DS-MIPv6 can't "discover" its HAs either, DHAAD is for IPv6 only.

=> Read section 2.1

Hesham

---

From: "Soliman, Hesham" <[email-masked]>
Date: Wed, 21 Jun 2006 07:40:36 -0700

> ("scale") than what the IPv4 protocol allows.  Does that makes sense?

=> No it doesn't. DSMIPv6 does NOT limit the operator from deploying
IPv6 only.
The desire to do that is completely orthogonal to DSMIPv6. If you want
to deploy IPv6 only without regard to IPv4 CNs then you would only use
MIPv6, or you might use NAT-PT, but that's not the IETF's
recommendation. DSMIPv6 is designed for roaming to IPv4 networks with
MIPv6, or for using an IPv4 HoA with MIPv6.

Hesham

---

From: Alexandru Petrescu <[email-masked]>
Date: Wed, 21 Jun 2006 17:02:07 +0200

>> DS-MIPv6 can't "discover" its HAs either, DHAAD is for IPv6 only.

Section 2.1 describes how the DS-MIPv6 MN discovers its HA by using DNS.

An MIPv6 node with IPv4 stack and v4 traversal can also "discover" the
address of the v4-v6 transition server this way.  The Server can be
Teredo, STUN or other.  Both are RFCs spec'ed and implemented.  Anything
can be "discovered" that way, just feed its name in the DNS and specify
that the administrator is responsible to put there the right A or AAAA
address.

I was thinking you people talk discovery in the terms of DHAAD, which is
different than DNS-based.  Check Router Discovery, DHCP Server
discovery, DHAAD and 6to4 Relay discovery.

Alex

---

From: Alexandru Petrescu <[email-masked]>
Date: Wed, 21 Jun 2006 16:52:26 +0200

Soliman, Hesham wrote:
>>>>  support IPv4 and IPv6 then all routers inside can't be HAs 
>>>> whose nodes attach to IPv4-only networks.
>>> 
>> With DS-MIPv6, the size of the operator's IPv6 infra can not grow 
>> larger ("scale") than what the IPv4 protocol allows.  Does that 
>> makes sense?
> 
>  IPv6 only. The desire to do that is completely orthogonal to
> DSMIPv6. If you want to deploy IPv6 only without regard to IPv4 CNs
> then you would only use MIPv6,

One operator can consider the IPv4 CNs,  deploy its IPv6-only
infrastructure, with MIPv6 HAs within it, with MNs running MIP6 and NAT
Traversal.  DS-MIPv6 doesn't allow that.

> or you might use NAT-PT, but that's not the IETF's recommendation.

I wasn't talking NAT-PT.

And what's _not_ the IETF recommendation?  I don't get it.  The IETF
recommendation is to not use NAT-PT?  I guess the IETF recommendation
_is_ to use existing IPv6 transition mechanisms wherever appropriate.

> DSMIPv6 is designed for roaming to IPv4 networks with MIPv6, or for 
> using an IPv4 HoA with MIPv6.

The first goal looks good.  The second is not necessary and I don't know
who asks for it.  If you remove the second goal (and let MIPv4 do it)
then one can get IPv6-only infrastructures for DS-MIPv6.

Alex

---

From: "Tsirtsis, George" <[email-masked]>
Date: Wed, 21 Jun 2006 09:34:12 -0700

The IPv4 address allocation part of DS-MIPv6 solution has the same
limitations an IPv4 deployment has. The operator may not have enough
public IPv4 addresses for everyone so it might use private IPv4 (and
NATs) instead. I do not see IPv4 operators today not being able to
expand their networks because of this. Why would that be the case in
DS-MIPv6??

> Sent: Wednesday, June 21, 2006 10:41 AM
> To: Alexandru Petrescu
> Cc: [email-masked]

---

From: Vijay Devarapalli <[email-masked]>
Date: Wed, 21 Jun 2006 11:17:21 -0700

> IPv6 split bootstrapping doesn't work over IPv4.

draft-ietf-mip6-nemo-v4traversal-01.txt extends the split
scenario bootstrapping mechanism to discover HA's IPv4
address. see section 2.1.

there was also a proposal to extend DHAAD to return HA's
IPv4 address in addition to the IPv6 address. but the
design team decided not to include this. HA discovery
through DNS was considered sufficient.

Vijay

---

From: Alexandru Petrescu <[email-masked]>
Date: Wed, 21 Jun 2006 21:56:53 +0200

Vijay Devarapalli wrote:
>>> I have nothing against gateway farms and they can certainly used
>>>  like that. Problem is that the end node needs to either be 
>>> preconfigured with them or have yet another way to discover them,
>>>  a way to create a security association with them, a way to deal
>>>  with failures etc etc. Re-using the HAs makes some sense in that
>>>  respect.
>> 
>> 
>>  discovery mechanisms.  However doesn't work behind NAT.  "Gateway"
>>  farms can be Teredo Servers, or  STUN Servers.  These don't have a
>>  over-the-Internet discovery mechanisms, they should be 
>> pre-configured on the MNs.
>> 
> draft-ietf-mip6-nemo-v4traversal-01.txt extends the split scenario 
> bootstrapping mechanism to discover HA's IPv4 address. see section 
> 2.1.

That should be re-named from "discovery" to "DNS resolution".  Other
"discovery" mechanisms (DHCP Server discovery, DHAADiscovery,
MLDiscovery, ND router discovery) don't rely on DNS to discover.  I know
of no discovery relying on DNS, you may know better - please let me know.

Resolving the DNS name can happen also to find out a 6to4 Relay, but in
practice different people provide different Relays and there's no
centralized point who could manage a generic say 6to4.net address.

If one would like HA service to be offered by various servers
controlled independently then one can't rely on DNS resolution for
discovery.

> there was also a proposal to extend DHAAD to return HA's IPv4 address
>  in addition to the IPv6 address.

Sounds as a good idea, except the DHAAD messaging should happen over a
form of IPv4 anycast addressing which doesn't seem to exist.  Or the use
of an IPv4 multicast address was proposed?

Alex

---

From: Alexandru Petrescu <[email-masked]>
Date: Wed, 21 Jun 2006 22:22:02 +0200

Tsirtsis, George wrote:
>  NATs) instead.[...] Why would that [not] be the case in DS-MIPv6??

An operator using NATs to offer IPv4 home addresses do so without
offering reachability at that permanent IPv4 home address.  Would
DS-MIPv6 allow this?

I really think we should come back to original requirements and goals
here...  The problem is simple: offer session continuity and
reachability at permanent IPv4 and IPv6 addresses.

> I do not see IPv4 operators today not being able to expand their 
> networks because of this.

Even if an operator uses the entire class A (24bits), and the class B
(20bits), and the class C (16bits) allocated by IANA for private IPv4
addresses, their number does not amount to what IPv6 80bits has to
offer.  The private IPv4 address space is defined in rfc1918.  The IPv6
address space is in rfc3513.

Alex

> 
>> -----Original Message----- From: Soliman, Hesham 
>> [mailto:[email-masked]] Sent: Wednesday, June 21, 2006 10:41
>>  AM To: Alexandru Petrescu Cc: [email-masked] Subject: RE: [Mip6] 
>> FW: Internal WG Review: Recharter ofMobility for IPv4(mip4)
>> 
>> 
>>>>> I mean an IPv6-only network is very large.  If only its 
>>>>> borders support IPv4 and IPv6 then all routers inside can't 
>>>>> be HAs whose nodes attach to IPv4-only networks.
>>>> 
>>> makes
> sense?
>> => No it doesn't. DSMIPv6 does NOT limit the operator from 
>> deploying IPv6 only. The desire to do that is completely orthogonal
>>  to DSMIPv6. If you want to deploy IPv6 only without regard to IPv4
>>  CNs then you would only use MIPv6, or you might use NAT-PT, but 
>> that's not the IETF's recommendation. DSMIPv6 is designed for 
>> roaming to IPv4 networks with MIPv6, or for using an IPv4 HoA with 
>> MIPv6.
>> 
>> Hesham
>> 
>> _______________________________________________ Mip6 mailing list 
>> [email-masked] https://www1.ietf.org/mailman/listinfo/mip6

---

From: Vijay Devarapalli <[email-masked]>
Date: Wed, 21 Jun 2006 14:02:47 -0700

Alexandru Petrescu wrote:
>> bootstrapping mechanism to discover HA's IPv4 address. see section 2.1.
> 
> 

note that HA discovery throught DNS is not mandated. you can
use your favorite mechanism (deployment specific) to configure
the mobile node with the HA information.

> of an IPv4 multicast address was proposed?

the solution was limited to performing DHAAD only when the MN
is attached to an IPv6 access network. there was no extension
to DHAAD to work over IPv4.

Vijay

---

From: Alexandru Petrescu <[email-masked]>
Date: Wed, 21 Jun 2006 23:27:44 +0200

Tsirtsis, George wrote:
> Sure it does.

Ok, so DS-MIPv6 does not have as a goal to offer reachable IPv4 Home
Addresses for Mobile Nodes.

>> I really think we should come back to original requirements and 
>> goals here...  The problem is simple: offer session continuity and 
> I do not think that "permanent" IPv4 addresses is a goal.

Good to know DS-MIPv6 does not try to offer reachable IPv4 home addresses.

> If we could give permanent IPv4 addresses we would not have to spend
>  10 years on IPv6.

:-)

> All we need is to allow DS nodes to be able to communicate with the 
> IPv4 internet while they are moving around.

If the HoA is behind NAT, thus not reachable, it's little useful for HA
to maintain associations IPv4 CoA-HoA, because HA would not receive
packets initiated by CN, even though HA would know where to forward the
IPv4 traffic (the CoA).

There are particular apps where traffic is initiated by IPv4 HoA towards
IPv4 CN.  In this case the MN could as well use its IPv4 CoA for
initiation and not reverse tunnel to HA.

In those two cases I don't see the need for DS-MIPv6 HA to maintain
associations IPv4 HoA-CoA.

> The IPv6 part of the stack offers the permanent address the end node
>  needs.

Yes, the permanent reachable IPv6 home address for session continuity,
but not the v4 address.

>> Even if an operator uses the entire class A (24bits), and the class
>>  B (20bits), and the class C (16bits) allocated by IANA for private
>>  IPv4 addresses, their number does not amount to what IPv6 80bits 
>> has to offer.  The private IPv4 address space is defined in 
>> rfc1918.  The IPv6 address space is in rfc3513.
>> 
> 
> The Internet today has done fine with this space and I have yet to 
> find a company that is running out of private address space to use.

Right, I agree with it.  And many infrastructures use several levels of
NATs and MPLS.

> BTW, IPv6 does not offer 80bits to anyone since most allocations are
>  supposed to be /64 or larger.

80bit space is larger than 64bit space, ok.

A company asking for an IPv6 prefix from a RIR could easily get 80bit
space (i.e. a /48 prefix).  If it can't then just use 6to4 - that can.

Besides, a more motivated company would manage 6to4 relays for itself
in which case it could get 80bit space times the number of IPv4
addresses it already has, that's really big.  An even more motivated
would propose a 6to4 method that wouldn't require the 32bits of the IPv4
address to be public, but private, just like in NAT, so it could build
its own IPv6 128bit space, as big as the Internet, and still not
reachable from it :-)

Alex

---

From: Alexandru Petrescu <[email-masked]>
Date: Wed, 21 Jun 2006 23:32:27 +0200

Vijay Devarapalli wrote:
>>>>> I have nothing against gateway farms and they can certainly 
>>>>> used like that. Problem is that the end node needs to either 
>>>>> be preconfigured with them or have yet another way to 
>>>>> discover them, a way to create a security association with 
>>>>> them, a way to deal with failures etc etc. Re-using the HAs 
>>>>> makes some sense in that respect.
>>>> 
>>>> 
>>>> 
>>>> "Gateway" farms can simply be 6to4 Relays.  They have their 
>>>> anycast discovery mechanisms.  However doesn't work behind NAT.
>>>>  "Gateway" farms can be Teredo Servers, or  STUN Servers. These
>>>>  don't have a over-the-Internet discovery mechanisms, they 
>>>> should be pre-configured on the MNs.
>>>> 
>>> scenario bootstrapping mechanism to discover HA's IPv4 address. 
>>> see section 2.1.
>> 
>> 
>> MLDiscovery, ND router discovery) don't rely on DNS to discover. I
>>  know of no discovery relying on DNS, you may know better - please
>>  let me know.
>> 
>> Resolving the DNS name can happen also to find out a 6to4 Relay, 
>> but in practice different people provide different Relays and 
>> there's no centralized point who could manage a generic say 
>> 6to4.net address.
>> 
> note that HA discovery throught DNS is not mandated. you can use your
>  favorite mechanism (deployment specific) to configure the mobile 
> node with the HA information.

Ok.  Some deployments will use pre-configured information on the mobile.

>>> there was also a proposal to extend DHAAD to return HA's IPv4 
>>> address in addition to the IPv6 address.
>> 
>> 
>> Sounds as a good idea, except the DHAAD messaging should happen 
>> over a form of IPv4 anycast addressing which doesn't seem to exist.
>>  Or the use of an IPv4 multicast address was proposed?
> 
> the solution was limited to performing DHAAD only when the MN is 
> attached to an IPv6 access network. there was no extension to DHAAD 
> to work over IPv4.

That sounds like an even better idea.  When attached to an IPv6 network
use DHAAD to discover both the v4 and the v6 home agent addresses.
There would be a need for the IPv4 and IPv6 HAs to talk to each other,
inform their addresses, but that would be feasible by extending the RA
part and/or other inter-HA synch protocol.

Alex

---

From: "Tsirtsis, George" <[email-masked]>
Date: Wed, 21 Jun 2006 13:33:26 -0700

> Sent: Wednesday, June 21, 2006 4:22 PM
> To: Tsirtsis, George

Sure it does.

> reachability at permanent IPv4 and IPv6 addresses.

I do not think that "permanent" IPv4 addresses is a goal. If we could
give permanent IPv4 addresses we would not have to spend 10 years on
IPv6. All we need is to allow DS nodes to be able to communicate with
the IPv4 internet while they are moving around. The IPv6 part of the
stack offers the permanent address the end node needs.

> address space is in rfc3513.

The Internet today has done fine with this space and I have yet to find
a company that is running out of private address space to use. BTW, IPv6
does not offer 80bits to anyone since most allocations are supposed to
be /64 or larger.

---

From: Michael Ye <[email-masked]>
Date: Thu, 22 Jun 2006 09:03:41 +0800

-----Original Message-----
From: Alexandru Petrescu [mailto:[email-masked]] 
Sent: Wednesday, June 21, 2006 10:33 PM
To: Tsirtsis, George
Cc: [email-masked]; Soliman, Hesham
Subject: Re: [Mip6] FW: Internal WG Review: Recharter ofMobility for
IPv4(mip4)

Tsirtsis, George wrote:
> There is no complaint. I am simply pointing out that if you use HAs 
> and a Gateway (of whatever form) you have to discover, manage and 
> secure two entities instead of one.

==>Yes,DS-MIPv6 MN must discover its HA when it moves into the heterogeneous
network even in same network.
==>So maintaining its connectivity must base on the HA (or HoA).

Alex

Michael

---

From: "Soliman, Hesham" <[email-masked]>
Date: Wed, 21 Jun 2006 20:58:10 -0700

> Addresses for Mobile Nodes.

=> You can't conclude that from the response above. DSMIP does allow a
MN to have an IPv4 HoA but it's not mandatory. So if you want to use
IPv6-only HoAs then you can use DSMIPv6 to roam in IPv4 networks. If you
want to use IPv6 and IPv4 HoAs you can use DSMIPv6 for both IPv4 HoA and
CoA. I really can't explain this any more than that.

 > Good to know DS-MIPv6 does not try to offer reachable IPv4 

=> Somehow you replaced "permanent" with "reachable". DSMIPv6 allows a
MN to have an IPv4 address (private or public is irrelevant to DSMIPv6).

Hesham

---

From: Alexandru Petrescu <[email-masked]>
Date: Thu, 22 Jun 2006 08:29:55 +0200

Soliman, Hesham wrote:
>> Tsirtsis, George wrote:
>>>> An operator using NATs to offer IPv4 home addresses do so 
>>>> without offering reachability at that permanent IPv4 home 
>>>> address.  Would DS-MIPv6 allow this?
>>>> 
>>> 
>>> Sure it does.
>> 
>> Ok, so DS-MIPv6 does not have as a goal to offer reachable IPv4 
>> Home Addresses for Mobile Nodes.
> 
> => You can't conclude that from the response above. DSMIP does allow 
> a MN to have an IPv4 HoA but it's not mandatory. So if you want to 
> use IPv6-only HoAs then you can use DSMIPv6 to roam in IPv4 networks.
>  If you want to use IPv6 and IPv4 HoAs you can use DSMIPv6 for both 
> IPv4 HoA and CoA. I really can't explain this any more than that.

Hesham, if we discuss this with a goals perspective, do you think
DS-MIPv6 has among its goals to offer session continuity and
reachability at a permanent IPv4 HoA?  It seems the reachability part is
not really a goal.  That is good to know.

It's useless to continue claiming features as if one were trying to sell
a protocol based on its wide range of features.  Does the protocol have
_any_ shortcoming?

> => Somehow you replaced "permanent" with "reachable".

YEs, because somehow my correspondent considered that NAT can't offer
"permanent" addresses while it actually can't offer "reachable"
addresses.  MAkes sense?  Quoting the whole discussion can help.

Directly replacing avoided me asking whether he meant "permanent" or
"reachable", I'm sure he meant reachable.

> DSMIPv6 allows a MN to have an IPv4 address (private or public is 
> irrelevant to DSMIPv6).

I think DS-MIPv6 wouldn't work when the IPv4 HoA is private (thus not
reachable) because the HA is behind NAT, so the BU (encapsulated in
IPv4) wouldn't reach the HA, right?

Alex

---

From: "Soliman, Hesham" <[email-masked]>
Date: Thu, 22 Jun 2006 00:38:54 -0700

> not really a goal.  That is good to know.

=> You've lumped about 10 features in one statement. Here are the two
goals of DSMIPv6: 
  1. Allow a mobile node to have IPv4 and IPv6 HoA simultaneously.
  2. Allow a MN to have an IPv4. 
To be realistic, goal 2) requires NAT traversal since a lot of networks
use private addresses. That's it. These are the two goals. 

 > a protocol based on its wide range of features.  

=> It's actually useless to keep repeating the same thing once a month.
Please be constructive and help in reducing the amount of repetition
here.

 > IPv4) wouldn't reach the HA, right?

=> Please read the draft. It's not possible to have a discussion when
you keep claiming things that are easily nullified by reading the
document. 

Hesham

---

From: Alexandru Petrescu <[email-masked]>
Date: Thu, 22 Jun 2006 11:55:37 +0200

> use private addresses. That's it. These are the two goals. 

Ok, if the IPv4 HoA is behind NAT I don't think DS-MIPv6' NAT Traversal
can help with it.

Alex

---

From: Alexandru Petrescu <[email-masked]>
Date: Mon, 26 Jun 2006 19:50:38 +0200

> network even in same network.

I suggest re-naming HA "discovery" based on DNS to DNS-resolution of the 
HA name.  None of the existing discovery mechanisms rely on DNS.

Alex