Subject: [5gangip] Reviewing GTP (was: re: Notes from today's meeting)

From: John Grant <[email-masked]>
Date: Thu, 29 Mar 2018 11:38:02 +0100

On Mon, Mar 26, 2018 at 4:49 AM, Alexandre Petrescu<alexandre.petrescu at gmail.com 
<mailto:alexandre.petrescu%20at%20gmail.com>>  wrote:

    Le 23/03/2018 à 09:08, Jon Crowcroft a écrit :

        is there a technical reason we can't just re-visit MIPv6 in 5g
        in 2018?

    If it were up to me...

    To revisit, I would start looking at the tunnelling mechanism, identify
    what's missing from GTP, or how is it too heavy.

That's something we're looking at in ETSI ISG NGP 
http://www.etsi.org/technologies-clusters/technologies/next-generation-protocols

There's also a one-day workshop on the topic in Cambridge at the end of 
April 
https://www.cambridgewireless.co.uk/events/uk5g-death-ip-realising-opportunities-next-generat/

-- 
John Grant
Nine Tiles, Cambridge, England
+44 1223 862599 and +44 1223 511455
http://www.ninetiles.com

---

From: Ca By <[email-masked]>
Date: Thu, 29 Mar 2018 12:06:33 +0000

On Thu, Mar 29, 2018 at 3:37 AM John Grant <[email-masked]> wrote:

> On Mon, Mar 26, 2018 at 4:49 AM, Alexandre Petrescu <alexandre.petrescu at gmail.com> wrote:
>
>
>>
>>> is there a technical reason we can't just re-visit MIPv6 in 5g in 2018?
>>>
>>
>> If it were up to me...
>>
Hopefully your event will be more effective at creating an actionable
problem statement than this group has been.

Protip: “too old” and “too heavy” are not substantiate problem statements
that can funnel into a business case to drive architectual action.

-- 
> +44 1223 862599 and +44 1223 511455http://www.ninetiles.com
>
>
>
> _______________________________________________
> 5gangip mailing list
> [email-masked]
> https://www.ietf.org/mailman/listinfo/5gangip
>

---

From: Behcet Sarikaya <[email-masked]>
Date: Thu, 29 Mar 2018 09:56:53 -0500

On Thu, Mar 29, 2018 at 7:06 AM, Ca By <[email-masked]> wrote:

>> That's something we're looking at in ETSI ISG NGP http://www.etsi.org/
>> technologies-clusters/technologies/next-generation-protocols
>>
>> April https://www.cambridgewireless.co.uk/events/uk5g-death-ip-
>> realising-opportunities-next-generat/
>> <https://www..cambridgewireless.co.uk/events/uk5g-death-ip-realising-opportunities-next-generat/>
>>
>>

Hopefully so.
We delegated the PS writing to the workshop, once they have it we are going
to submit it to the required places :-)

Behcet

>> Nine Tiles, Cambridge, England+44 1223 862599 <+44%201223%20862599> and +44 1223 511455 <+44%201223%20511455>http://www.ninetiles.com
>>
>>
>>

---

From: Alexandre Petrescu <[email-masked]>
Date: Thu, 29 Mar 2018 18:00:29 +0200

Le 29/03/2018 à 14:06, Ca By a écrit :
>
> On Thu, Mar 29, 2018 at 3:37 AM John Grant <[email-masked] 
> <mailto:[email-masked]>> wrote:
>
>     There's also a one-day workshop on the topic in Cambridge at the
>     end of April
> Protip: “too old” and “too heavy” are not substantiate problem 
> statements that can funnel into a business case to drive architectual 
> action.

Instead of "too heavy" how about "lack of RFC reference of gtp-user"?

In the figures below, compare the absence vs presence of value  in 
column Reference.

And, speaking of port numbers, I wonder whether their space is limited 
to 65535.  The highest number seems to be 49151 for 'inspider' allocated 
on November 6th, 2017.  Are we running out of port number space?  When 
we run out, will we  re-use those that dont have RFC in the Reference 
column, first?

I must confess that I am not aware at all about how this is managed.   
Maybe the management takes care of this entirely, and the two problems 
("lack of RFC reference for gtp-user" and "running out of port space") 
are not really problems.

Just some thought.

Alex

>     [email-masked] <mailto:[email-masked]>

---

From: Charlie Perkins <[email-masked]>
Date: Thu, 29 Mar 2018 09:03:34 -0700

Hello folks,

> statements that can funnel into a business case to drive architectual 

Does anyone have crisp statements about what is wrong with GTP?

Does anyone have a statement about a problem or pain point that 5G 
operators want solved?

Shouldn't the problem ought to be related to mobility management, if we 
are to tackle it in the [dmm] working group?  Someone mentioned that a 
solution for mobility between heterogeneous media was required.  But, 
when I suggested an approach known to work, then the answer was that 
solution did not address the problems not related to mobility.

At one point I became convinced that we should have named the IETF 
solution to be GTPv2+

Regards,
Charlie P.

---

From: Ca By <[email-masked]>
Date: Thu, 29 Mar 2018 16:18:03 +0000

> Instead of "too heavy" how about "lack of RFC reference of gtp-user"?

Does ethernet also lack an RFC?  HTML? ToR?

Just like ethernet, GTP is a product of a different SDO.

>
> In the figures below, compare the absence vs presence of value  in column
> Reference.
>
>
>
>
>
> And, speaking of port numbers, I wonder whether their space is limited to
> 65535.  The highest number seems to be 49151 for 'inspider' allocated on
> November 6th, 2017.  Are we running out of port number space?  When we run
> out, will we  re-use those that dont have RFC in the Reference column,
> first?
>

Again, GTP is documented in 3GPP. There are many interworking
implementations of it.

I am sure you can google all that.  If you need an RFC, you can look up
opensource GTP code and 3GPP docs to write one.

> ("lack of RFC reference for gtp-user" and "running out of port space") are
> not really problems.
>
> Just some thought.
>
> Alex
>
>
>
>
> --
>> John Grant
> 5gangip mailing [email-masked]://www.ietf.org/mailman/listinfo/5gangip
>
>
>

---

From: John Grant <[email-masked]>
Date: Thu, 29 Mar 2018 17:34:48 +0100

On 29/03/2018 17:00, Alexandre Petrescu wrote:

[snip]

> to 65535.  The highest number seems to be 49151 for 'inspider' 
> allocated on November 6th, 2017.  Are we running out of port number 
> space?  When we run out, will we  re-use those that dont have RFC in 
> the Reference column, first?
As explained at 
http://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xml 
and in RFC6335, the top 16K values are "dynamic" port numbers; 
typically, when you bind() a socket it is given one of those. The rest 
are the "well-known" port numbers; the allocations are quite sparse 
above about 25000 so I don't think they're likely to run out any time 
soon. I'd guess when they do run out there'll be a survey to identify 
ones that aren't used any more. Or maybe IP will be obsolete before then :-)
-- 

John Grant

---

From: John Grant <[email-masked]>
Date: Thu, 29 Mar 2018 17:50:04 +0100

> Does anyone have crisp statements about what is wrong with GTP?
In NGP's Scenarios document 
http://www.etsi.org/deliver/etsi_gs/NGP/001_099/001/01.02.01_60/gs_NGP001v010201p.pdf 
we talk about that, though perhaps not very crisply. Some of the other 
material at 
http://www.etsi.org/technologies-clusters/technologies/next-generation-protocols 
is maybe crisper.

> Does anyone have a statement about a problem or pain point that 5G 
The NGP Requirements document 
http://www.etsi.org/deliver/etsi_gs/NGP/001_099/005/01.01.01_60/gs_NGP005v010101p.pdf 
talks about that. We're now working on a more focussed KPIs document.

---

From: Alexandre Petrescu <[email-masked]>
Date: Thu, 29 Mar 2018 19:14:01 +0200

Le 29/03/2018 à 18:18, Ca By a écrit :
>
> On Thu, Mar 29, 2018 at 9:00 AM Alexandre Petrescu 
> <[email-masked] <mailto:[email-masked]>> 
> wrote:
>
>
>
>>         There's also a one-day workshop on the topic in Cambridge at
>>         the end of April
>>     Hopefully your event will be more effective at creating an
>>     actionable problem statement than this group has been.
>>
>>     statements that can funnel into a business case to drive
>>     architectual action.
>

HTML and Ethernet specs dont use port numbers, so no need of allocation.

ToR: like bitcoin, its use is of questionable legality in many places.  
It's a consent between adults.  Can't be standardized.

> Just like ethernet, GTP is a product of a different SDO.

YEs, but.

SDO could define a protocol it wishes, but should never be sure to keep 
the port number.

If I tell SDO (3GPP in this case) that the port number they so much 
believe to be interoperable (number 2152 decimal) can be actually used 
by somebody else any day, for something else than GTP; or that maybe 
IANA will simply allocate 2152 to somebody else because IANA runs out of 
space.  Then I am sure SDO (3GPP in this case) will not appreciate.

The result of that lack of appreciation is to write down an Internet Draft.

And then we will see.

>     And, speaking of port numbers, I wonder whether their space is
>     limited to 65535.  The highest number seems to be 49151 for
>     'inspider' allocated on November 6th, 2017.  Are we running out of
>     port number space?  When we run out, will we  re-use those that
>     dont have RFC in the Reference column, first?
>
>
> I am sure you can google all that.  If you need an RFC, you can look 
> up opensource GTP code and 3GPP docs to write one.

I think it is not me who needs it.  It is SDO who needs it.  But yes, I 
can write one.

Then IETF at large and IANA should agree with it.

Alex

>
>
>     I must confess that I am not aware at all about how this is
>     managed.   Maybe the management takes care of this entirely, and
>     the two problems ("lack of RFC reference for gtp-user" and
>     "running out of port space") are not really problems.
>
>     Just some thought.
>
>     Alex
>
>
>
>>
>>         -- 
>>         John Grant

---

From: John Grant <[email-masked]>
Date: Thu, 29 Mar 2018 18:19:12 +0100

Of course, the IP layers in GTP don't actually connect to the Internet, 
so I guess 3GPP can use whatever port numbers they want.

---

From: Alexandre Petrescu <[email-masked]>
Date: Thu, 29 Mar 2018 19:44:16 +0200

> so I guess 3GPP can use whatever port numbers they want.

In that case, they (SDO) should revoke the assignment of gtp-control 
port number at IANA (2123), so that somebody else can use it.  There is 
a IANA procedure for that.

Alex

---

From: Alexandre Petrescu <[email-masked]>
Date: Thu, 29 Mar 2018 20:05:39 +0200

> Does anyone have crisp statements about what is wrong with GTP?

I think it is a little bit strange to have an IP-based protocol in such 
widespread use without an RFC.

> At one point I became convinced that we should have named the IETF 

I would agree calling it GTPv2+.

I think GTPv2+ has advantages over GTP, e.g. it's proven to work
natively with IPv6, whereas GTP no.

Alex

---

From: Satoru Matsushima <[email-masked]>
Date: Fri, 30 Mar 2018 14:12:05 +0900

Hello John,

If it would useful, I’d like to cooperate that GTP review work at user plane point of view. Thanks.

Cheers,
--satoru

> 2018/03/29 19:38、John Grant <[email-masked]>のメール:
> 
> That's something we're looking at in ETSI ISG NGP http://www.etsi.org/technologies-clusters/technologies/next-generation-protocols
> 
> There's also a one-day workshop on the topic in Cambridge at the end of April https://www.cambridgewireless.co.uk/events/uk5g-death-ip-realising-opportunities-next-generat/
> -- 
> John Grant

---

From: Behcet Sarikaya <[email-masked]>
Date: Fri, 30 Mar 2018 10:26:15 -0500

Hi Satoru,

> plane point of view. Thanks.
Thanks for the offer but I think you are confused of what is going on below
in the mails, so many people's mails including two John's, Jon Crowcroft
and John Grant.

Reviewing GTP is an idea we have in 5gangip and currently Alex is taking
the lead.
As a GTP expert you are welcome to join him.

Alex has this ambitious idea of writing a draft (not an RFC, we do not
write RFCs, some drafts become RFCs) on GTP which could be used as a
reference to GTP in IETF (to enable the operators  to run GTP in IPv6).

In our case, we encourage writing a requirements document for end to end
privacy enabled mapping system for 5G for which the starting point should
be the GTP and address the issues of tunneling and other aspects.

I believe this has nothing to do with what is going on in dmm.

Regards,
Behcet

Cheers,
> > On Mon, Mar 26, 2018 at 4:49 AM, Alexandre Petrescu <alexandre.petrescu
> at gmail.com>
> >  wrote:
> >
> >
> >

---

From: Satoru Matsushima <[email-masked]>
Date: Sat, 31 Mar 2018 11:05:23 +0900

Thank you Behcet,

Ok, I was supposed that Alex is going to make a reference doc for GTP in IETF, and John is going to review GTP in ETSI.

As I mentioned at last DMM meeting, investigating GTP-U by IETF experts’s eyes is highly appreciated. Please see following link and find some GTP-U info. Maybe IETF-friendly style explanation is helpful for you. :-)

https://datatracker.ietf.org/meeting/101/materials/slides-101-dmm-study-on-user-plane-protocol-at-3gpp-00

I’m really happy to cooperate with all people those who are interested in to work on it.

Best regards,
--satoru

> 2018/03/31 0:26、Behcet Sarikaya <[email-masked]>のメール:
> 
> Hi Satoru,
> 
> On Fri, Mar 30, 2018 at 12:12 AM, Satoru Matsushima <[email-masked]> wrote:
> Hello John,
> 
> Thanks for the offer but I think you are confused of what is going on below in the mails, so many people's mails including two John's, Jon Crowcroft and John Grant.
> 
> Reviewing GTP is an idea we have in 5gangip and currently Alex is taking the lead.
> Alex has this ambitious idea of writing a draft (not an RFC, we do not write RFCs, some drafts become RFCs) on GTP which could be used as a reference to GTP in IETF (to enable the operators  to run GTP in IPv6).
> 
> In our case, we encourage writing a requirements document for end to end privacy enabled mapping system for 5G for which the starting point should be the GTP and address the issues of tunneling and other aspects.
>