Subject: Re: [v6ops] new draft: draft-chen-v6ops-ipv6-roaming-analysis

From: "Rajiv Asati (rajiva)" <[email-masked]>
Date: Thu, 1 Aug 2013 20:43:18 +0000

Cameron,

Thanks for the details. Is there an implicit assumption that the roaming
partners' backend system understands v6 PDP, but not v4v6 PDP?

Cheers,
Rajiv

-----Original Message-----
From: Cameron Byrne <[email-masked]>
Date: Monday, July 29, 2013 3:59 PM
To: Rajiv Asati <[email-masked]>
Cc: "Fred Baker (fred)" <[email-masked]>, "[email-masked]"
<[email-masked]>, "[email-masked]"
<[email-masked]>
Subject: Re: [v6ops] new draft: draft-chen-v6ops-ipv6-roaming-analysis

>Rajiv
>
>On Mon, Jul 29, 2013 at 12:00 PM, Rajiv Asati (rajiva) <[email-masked]>
>wrote:
>> Hi Cameron,
>>
>> Could you please share more details about 3a and 3b below?
>>
>>
>
>Can you be more specific about the question?
>
>Charging systems have a hard time to reconcile usage from 2 PDP
>because they are 2 separate CDRs, 1 for each PDP.  Also, 2 PDP is 2x
>as expensive in terms of signalling and licensing.
>
>v4v6 as single PDP is not viable because not everything supports
>release 8 in the GSM/3GPP ecosystem.  I tried to enable v4v6 for my
>subscribers in my central database (HLR/HSS), and adding this
>capability to all my subscribers made some existing ipv4 roaming
>subscribers fail.   Why?  Because when my users attach into a roaming
>partner network, their network downloads the capabilities of the
>subscriber from my database (HLR/HSS)... and if one of the
>capabilities includes v4v6, then the roaming partners's equipment
>drops the users because they don't understand this term.
>
>This is a roaming partner network device acting in a bad and
>non-standard way.  It's a shame i have to turn off v4v6 globally
>because of this issue.  There is one subscriber database, and because
>some roaming partner gear fails, it is not safe to turn anywhere.  One
>remediation is to limit attributes based on a whitelist / blacklist,
>but this is not feature available today.
>
>Luckily, the good people of v6ops have approved RFC6877 and Android
>implemented it in 4.3 , so single v6 PDP works ok.
>
>
>> WOuldn't the UE fallback to v4 PDP, if v4v6 PDP wasn't available?
>>
>
>Yes, it's supposed to work that way.  But, keep in mind what i said
>above.  In the real world, it does not (for now, once everyone
>upgrades maybe this wont be a problem).
>
>Cameron
>
>> Cheers,
>> Rajiv
>>
>> -----Original Message-----
>> From: Cameron Byrne <[email-masked]>
>> Date: Sunday, July 28, 2013 11:48 AM
>> To: "Fred Baker (fred)" <[email-masked]>
>> Cc: "[email-masked]" <[email-masked]>,
>> "[email-masked]"
>> <[email-masked]>
>> Subject: Re: [v6ops] new draft: draft-chen-v6ops-ipv6-roaming-analysis
>>
>>>As general feedback
>>>
>>>1. As others have noted, it is important to clarify that home routed
>>>is the default case and local-breakout is only relavent for IMS, but
>>>IMS based roaming and local breakout is yet to see its first
>>>deployment, and may still be years in the future for roaming to work
>>>this way.  So, local breakout is not  a real case and seems to be
>>>causing more confusion.
>>>
>>>2.  There is a hazard in assuming the well known prefix is always
>>>available.  Any device should not assume the well known prefix is
>>>available.  This is essentially a misconfiguration that should not
>>>occur.
>>>
>>>3.  What i have learned
>>>
>>>a.  dual-stack 2 PDP will never work, charging issues in the billing
>>>system, and too much capacity wasted for no real gain
>>>
>>>b.  dual-stack 1 PDP (v4v6) will not work any time soon.  Enabling
>>>this feature in the HSS/HLR breaks roaming and there is no way to
>>>ensure this issue is fixed in the hundreds of networks that are
>>>potentially impacted.  There are some backs to do on the home network
>>>that can make this easier but not exposing partner networks to the new
>>>release 8 features.
>>>
>>>c.  What does work and adds value (saves IPv4 address for the common
>>>case of not-roaming) :  IPv6-only single PDP 464XLAT on the home
>>>network, IPv4-only single PDP when roaming.  This is how i am moving
>>>forward.  The when at home, the UE has default configs for ipv6-only
>>>and when roaming the ue only attempts to connect using IPv4.  This
>>>gets the vast majority of users in my home network off v4 and keeps
>>>ipv4 for the complicated yet relatively small percentage of roaming
>>>users.
>>>
>>>
>>>
>>>On Tue, Jul 9, 2013 at 5:45 AM,  <[email-masked]> wrote:
>>>>
>>>> A new draft has been posted, at
>>>>http://tools.ietf.org/html/draft-chen-v6ops-ipv6-roaming-analysis.
>>>>Please take a look at it and comment.
>>>> _______________________________________________
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>>>> https://www.ietf.org/mailman/listinfo/v6ops
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>>