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Re: New Version Notification for draft-koodli-ipv6-in-mobile-networks-02
Hi Teemu,
We need to separate this into what is already specified and what the draft
is saying. This draft is not introducing a host change in the form of DHCP.
3GPP has already included DHCP as a mechanism. Please see below.
On 4/18/10 1:44 PM, "teemu.savolainen@nokia.com"
<teemu.savolainen@nokia.com> wrote:
> Hi Rajeev,
>
> I'm saying having DHCP for deferred address allocation is quite a host change:
> 1) a host has to support DHCP for 3GPP access at first place
If PGW includes a Deferred Address Allocation PCO in Create Session Response
(and hence no IPv4 address in it), the host has to do DHCP.
> 2) a host has to support deferred DHCP for 3GPP access (reserve/release
> on-demand)
Yes, some hosts do this based on application trigger. OTOH, you could
initiate DHCP right away (after attach) but the network could use shorter
lease times.
> 3) a host has to support negotiation of used address allocation mechanism for
> 3GPP access:
> 3a) A host will have to ask if DHCP is used for this particular PDN connection
> 3b) If DHCP is not used, host shall get the address from bearer signaling
> instead
Yes. This is part of 3GPP TS 23.401, TS 29.274/5.
> Also in LTE the DHCP is optional for both host and network.
My understanding is that the assignment at attach is default, but PGW may
choose to instead use DHCP.
>
> So what I'm also saying is that it is not so straightforward to use IPv4
> on-demand with DHCP as I think the draft is implying (but maybe it is just my
> view), which is a concern for feasibility of this approach (recall how in 3GPP
> discussions getting transition mechanism changes to hosts was considered so
> hard).
>
Let us try to separate the issues here.
1. When DHCP is initiated. 1a) right after attach, 1b) as a response to an
application trigger. Your concern is with 1b) right?
2. Regardless of 1a), 1b), a network could use lease times of its choice
right (subject to pros/cons)?
> This DHCPv4 on-demand sound for me quite like a host based transition
> mechanisms (DSTM without encapsulation?).
Hmm..interesting. Going by this, one could argue that DHCP with shorter
lease times is host based transition, and the network cleaning up PDN/PDP
sessions due to timers is network-based transition :-)
>
> Furthermore, to gain real benefits a significant host population should
> support this, and it may or may not be a challenge depending on LTE deployment
> schedules and speed.
>
IMO, a mobile network provider may require DHCP from vendors. Not all
providers may go for it, but some may find it useful.
Thanks,
-Rajeev
> Best regards,
>
> Teemu
>
>> -----Original Message-----
>> From: ext Koodli, Rajeev [mailto:rkoodli@cisco.com]
>> Sent: 16. huhtikuuta 2010 20:53
>> To: Savolainen Teemu (Nokia-D/Tampere); v6ops@ops.ietf.org
>> Subject: RE: New Version Notification for draft-koodli-ipv6-in-mobile-
>> networks-02
>>
>>
>> Hi Teemu,
>>
>> thanks for the input.
>>
>> Agree to your point about adding IPv6 features and not IPv4.
>> However, the description of DHCP-based addressing is for LTE, not 3G.
>> And the description is about having DHCP as a mechanism to manage the
>> available IPv4 addressing pool.
>> Are you saying that it should not be available or should not be used?
>>
>> Regards,
>>
>> -Rajeev
>>
>>
>>
>> -----Original Message-----
>> From: teemu.savolainen@nokia.com [mailto:teemu.savolainen@nokia.com]
>> Sent: Fri 4/16/2010 2:25 AM
>> To: Koodli, Rajeev; v6ops@ops.ietf.org
>> Subject: RE: New Version Notification for draft-koodli-ipv6-in-mobile-
>> networks-02
>>
>> Hi Rajeev, all,
>>
>> I'm worried about the on-demand DHCP based address allocation
>> descriptions herein.
>>
>> Majority of 3GPP devices do not implement DHCP at all today for 3GPP
>> access, because it is optional and gives very little when compared to
>> mandatory PPP-like address allocation during bearer establishment
>> procedures.
>>
>> Introduction of DHCP for significant host population (to get
>> statistical savings) just for the deferred IPv4 address allocation
>> feature does not sound right thing to do for me.
>>
>> We should be adding IPv6 features to hosts, not IPv4 features.
>>
>> Best regards,
>>
>> Teemu
>>
>>> -----Original Message-----
>>> From: owner-v6ops@ops.ietf.org [mailto:owner-v6ops@ops.ietf.org] On
>>> Behalf Of ext Rajeev Koodli
>>> Sent: 16. huhtikuuta 2010 01:05
>>> To: v6ops@ops.ietf.org
>>> Subject: FW: New Version Notification for draft-koodli-ipv6-in-
>> mobile-
>>> networks-02
>>>
>>>
>>> Hello folks,
>>>
>>> I was asked at the Anaheim meeting to clarify the intended audience
>> for
>>> this
>>> ID, which I have done in the Introduction; this document can be a
>>> useful
>>> reference for service providers and network designers.
>>> This ID does not propose any new protocols or suggest any new
>> protocol
>>> work.
>>>
>>> I also got a good review from Mohamed Boucadier (thanks!) which I
>> have
>>> addressed.
>>>
>>> It seemed there was good interest that this ID is useful.
>>>
>>> So, Chairs: how do we proceed?
>>>
>>> Thanks,
>>>
>>> -Rajeev
>>>
>>> http://tools.ietf.org/html/draft-koodli-ipv6-in-mobile-networks-02
>>>
>>>
>>>
>>> ------ Forwarded Message
>>> From: IETF I-D Submission Tool <idsubmission@ietf.org>
>>> Date: Tue, 13 Apr 2010 16:30:59 -0700 (PDT)
>>> To: Rajeev Koodli <rkoodli@cisco.com>
>>> Subject: New Version Notification for
>>> draft-koodli-ipv6-in-mobile-networks-02
>>>
>>>
>>> A new version of I-D, draft-koodli-ipv6-in-mobile-networks-02.txt has
>>> been
>>> successfully submitted by Rajeev Koodli and posted to the IETF
>>> repository.
>>>
>>> Filename: draft-koodli-ipv6-in-mobile-networks
>>> Revision: 02
>>> Title: Mobile Networks Considerations for IPv6 Deployment
>>> Creation_date: 2010-04-14
>>> WG ID: Independent Submission
>>> Number_of_pages: 15
>>>
>>> Abstract:
>>> Mobile Internet access from smartphones and other mobile devices is
>>> accelerating the exhaustion of IPv4 addresses. IPv6 is widely seen
>>> as crucial for the continued operation and growth of the Internet,
>>> and in particular, it is critical in mobile networks. This document
>>> discusses the issues that arise when deploying IPv6 in mobile
>>> networks. Hence, this document can be a useful reference for service
>>> providers and network designers.
>>>
>>>
>>>
>>> The IETF Secretariat.
>>>
>>>
>>>
>>> ------ End of Forwarded Message
>>>
>>
>