Jim,

I don’t disagree with your statement that some of my views are subjective.  
They are however the subjective views of an operator when the question was 
asked do we want CRH.

The answer remains yes – because agree with my views or disagree with them – it 
is the perceptions that I have that will dictate my purchasing over my network 
and my purchasing decisions will not in any way shape or form include SRv6.  
While I have spoken at length about each of the points below over many many 
emails over the last months, I won’t go into them again, but the answer remains 
the same.  Do I, as an operator, operating across 15 countries, with the 
largest fixed line fiber network on the African continent, want CRH.  Yes.  Do 
I want it because I believe it can give me advantages.  Yes.  Will I run SRv6 
on this network.  No.  Have I tested, implemented and used CRH successfully on 
our network.  Yes.

So – subjective or not – I will not rehash the same things I have said over and 
over again covering each of the below points in detail, but my answer remains 
the same – yes, from my perspective, I want CRH, I need CRH and CRH works for 
us.

Thanks

Andrew


From: James Guichard <james.n.guich...@futurewei.com>
Date: Tuesday, 26 May 2020 at 20:26
To: Andrew Alston <andrew.als...@liquidtelecom.com>, Mach Chen 
<mach.c...@huawei.com>, "Zafar Ali (zali)" <zali=40cisco....@dmarc.ietf.org>, 
Ron Bonica <rbonica=40juniper....@dmarc.ietf.org>, "Chengli (Cheng Li)" 
<c...@huawei.com>, 6man <6...@ietf.org>, "spring@ietf.org" <spring@ietf.org>
Subject: RE: CRH is not needed - Re: How CRH support SFC/Segment Endpoint 
option?

Hi Andrew,

Some of your comments about SRv6 are a little subjective.


  1.  You say SRv6 is complex and yet in its basic form it is simply a list of 
IPv6 addresses carried in a routing header which does not seem too difficult to 
understand especially in light of the fact that with CRH I have essentially the 
same thing albeit with another level of indirection to resolve the mappings.
  2.  You say SRv6 has massive overhead and yet there are several proposals in 
which that overhead can be compressed without having to implement a mapping 
system to resolve the indirection.
  3.  The overloading the IPv6 address space comment seems at best subjective 
given that the IPv6 address in the DA field for SRv6 on the wire looks no 
different than any other IPv6 packet; the fact that some router in the network 
locally defines a set of instructions to execute upon receipt of a packet using 
that IPv6 address is a local affair and of no particular concern to any other 
router. The same logic applies to things like policy-based routing where a 
router can implement some policy to direct a packet on a different path that no 
router upstream is aware of.
  4.  Given the long and quite exhausting email thread on violation of RFC8200 
it is apparent that not everyone agrees with you on this point and in fact I 
would go as far as to say the current text is pretty clear from an English 
language point of view that I find it interesting how many different 
interpretations have sprung up.
  5.  Network programming is a tool (that you are free to use or not) to enable 
innovation through locally defined instructions; again, how is this over 
engineered and if it is over engineered how can it also be inflexible? Seem to 
me that the complete opposite is true.

Thanks!

Jim

From: spring <spring-boun...@ietf.org> On Behalf Of Andrew Alston
Sent: Tuesday, May 26, 2020 7:59 AM
To: Mach Chen <mach.c...@huawei.com>; Zafar Ali (zali) 
<zali=40cisco....@dmarc.ietf.org>; Ron Bonica 
<rbonica=40juniper....@dmarc.ietf.org>; Chengli (Cheng Li) <c...@huawei.com>; 
6man <6...@ietf.org>; spring@ietf.org
Subject: Re: [spring] CRH is not needed - Re: How CRH support SFC/Segment 
Endpoint option?

Speaking as an operator that operates in 15 countries – yes – yes and yes again.

SRv6 will never find a home on our network – it is complex, it has massive 
overhead, it overloads the address space in ways that make me cringe, it 
currently (in my view) violates RFC8200, the network programming draft is so 
overengineered that it is entirely inflexible – where as CRH – is simple, it 
gives me exactly what we need, it is a building block to many other things in 
the pipe line, and it has been tested and is functional.

I will not begrude anyone who wants to run SRv6 – each to his own – but as an 
operator – I 100% want CRH – and I 100% do not believe that SRv6 is in any way 
shape or form an alternative to it – or something that I will ever run across 
any of the countries we operate in.

Thanks

Andrew

Do we really want this?

My two cents.

Best regards,
Mach

From: ipv6 [mailto:ipv6-boun...@ietf.org] On Behalf Of Zafar Ali (zali)
Sent: Tuesday, May 26, 2020 3:02 PM
To: Ron Bonica 
<rbonica=40juniper....@dmarc.ietf.org<mailto:rbonica=40juniper....@dmarc.ietf.org>>;
 Chengli (Cheng Li) <c...@huawei.com<mailto:c...@huawei.com>>; 6man 
<6...@ietf.org<mailto:6...@ietf.org>>; spring@ietf.org<mailto:spring@ietf.org>
Subject: CRH is not needed - Re: How CRH support SFC/Segment Endpoint option?

Hi,

It appears that some may have misunderstood the SRv6 solution and invented CRH.
It is good to clarify these points.

SRv6 offers the possibility to combine underlay and overlay instructions in a 
single SRH.
However,
·         This is entirely optional
·         If one would like to spread the source routed policy between multiple 
extension headers, one can use SRv6 to do this
o   SRH to hold the topological endpoints
o   Any combination of other extension headers to hold VPN and/or Service 
information. For example, SRH works seamlessly with NSH as documented in a WG 
document 
https://tools.ietf.org/html/draft-ietf-spring-nsh-sr-02<https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Ftools.ietf.org%2Fhtml%2Fdraft-ietf-spring-nsh-sr-02&data=02%7C01%7Cjames.n.guichard%40futurewei.com%7Cd9fae6e4cd674180ef6c08d8016c6b3b%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637260912479599089&sdata=URxBgQ0Z4vJb54I04o4JXoFo%2BnGET6jjQzkH9gFWqms%3D&reserved=0>.

Claiming that a new data plane is needed to achieve this separation is false.

Claiming that CRH is needed to decrease the overhead of source-routed policy in 
IPv6 is incorrect, too. Many members of the SPRING working group have produced 
documents to extend the SRv6 solution for the specific purpose of minimizing 
the MTU overhead and/or supporting very long SID-lists on legacy hardware.

Also, CRH is just a re-engineering of SR-MPLS Data Plane with IPv6 Control 
Plane [RFC8663] and RFC8663 is an already productized, deployed, proven, and 
standardized solution.

6man took 6 years to define SRH. The 6man WG spent a lot of efforts (1000s of 
email, dozens of document revision, dozens of IETF presentations, control plan 
work that is adopted by multiple workgroups, etc.).

There is no need to define a new data plane, new control plane and associated 
management plane for the same purpose the IETF across multiple areas has worked 
for years.

Thanks

Regards … Zafar


From: ipv6 <ipv6-boun...@ietf.org<mailto:ipv6-boun...@ietf.org>> on behalf of 
Ron Bonica 
<rbonica=40juniper....@dmarc.ietf.org<mailto:rbonica=40juniper....@dmarc.ietf.org>>
Date: Friday, May 22, 2020 at 10:17 AM
To: "Chengli (Cheng Li)" <c...@huawei.com<mailto:c...@huawei.com>>, 6man 
<6...@ietf.org<mailto:6...@ietf.org>>, 
"spring@ietf.org<mailto:spring@ietf.org>" 
<spring@ietf.org<mailto:spring@ietf.org>>
Cc: "spring@ietf.org<mailto:spring@ietf.org>" 
<spring@ietf.org<mailto:spring@ietf.org>>
Subject: RE: How CRH support SFC/Segment Endpoint option?

Cheng,

The sole purpose of a Routing header is to steer a packet along a specified 
path to its destination. It shouldn’t attempt to do any more than that.

The CRH does not attempt to deliver service function information to service 
function instances. However, it is compatible with:

-          The Network Service Header (NSH)
-          The Destination Options header that precedes the Routing header

Both of these can be used to deliver service function information to service 
function instances.

                                                                                
                                     Ron




Juniper Business Use Only
From: Chengli (Cheng Li) <c...@huawei.com<mailto:c...@huawei.com>>
Sent: Friday, May 22, 2020 2:56 AM
To: 6man <6...@ietf.org<mailto:6...@ietf.org>>; 
spring@ietf.org<mailto:spring@ietf.org>; Ron Bonica 
<rbon...@juniper.net<mailto:rbon...@juniper.net>>
Cc: spring@ietf.org<mailto:spring@ietf.org>
Subject: How CRH support SFC/Segment Endpoint option?

[External Email. Be cautious of content]

Hi Ron,

When reading the CRH draft, I have a question about how CRH support SFC?

For example, we have a SID List [S1, S2, S3, S4, S5], and S3 is a SFC related 
SID, how to indicate that? By PSSI? [1]

But how to know which segment endpoint node/egress node should process this 
PSSI? At the beginning of the SRm6 design, this is described in [2]. But you 
deleted the containers [2].

Without that, I don’t really understand how SFC can be supported.


Best,
Cheng



[1]. 
https://tools.ietf.org/html/draft-bonica-spring-sr-mapped-six-01#section-4.1<https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Furldefense.com%2Fv3%2F__https%3A%2Ftools.ietf.org%2Fhtml%2Fdraft-bonica-spring-sr-mapped-six-01*section-4.1__%3BIw!!NEt6yMaO-gk!UD4vf0darQ9cskFhH1fJ9jwZJ-nIciQxgVnf1219YuyyaNcgvNdRUdkjwP15i-Xa%24&data=02%7C01%7Cjames.n.guichard%40futurewei.com%7Cd9fae6e4cd674180ef6c08d8016c6b3b%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637260912479599089&sdata=BToX91XT%2BlfL5xVfXbDTnE8Nt0%2F8x0PGbKx8mNd1UEY%3D&reserved=0>
[2]. 
https://tools.ietf.org/rfcdiff?url2=draft-bonica-6man-seg-end-opt-04.txt<https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Furldefense.com%2Fv3%2F__https%3A%2Ftools.ietf.org%2Frfcdiff%3Furl2%3Ddraft-bonica-6man-seg-end-opt-04.txt__%3B!!NEt6yMaO-gk!UD4vf0darQ9cskFhH1fJ9jwZJ-nIciQxgVnf1219YuyyaNcgvNdRUdkjwNmXwyHT%24&data=02%7C01%7Cjames.n.guichard%40futurewei.com%7Cd9fae6e4cd674180ef6c08d8016c6b3b%7C0fee8ff2a3b240189c753a1d5591fedc%7C1%7C0%7C637260912479609080&sdata=AquUOTV8I2X86h97RnCgdz0kx6x47Yt6FUrsADofsnU%3D&reserved=0>.


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