Re: [Int-area] IP Protocol number allocation request for Transparent Inter Process Communication (TIPC) protocol

[Jon Maloy <[e-mail]>]

On 3/18/20 12:04 AM, Joseph Touch wrote:
> Hi all,
>
> I’m quite confused by this request.
>
> It seems like they either have an implementation issue (in Linux).
Linux "passthru" GSO is implemented so that any IP based protocol which 
wants to benefit
from it needs its own IP protocol number. Doing this generically through 
the already existing
UDP protocol number is not possible, because GSO on a host must be 
implemented
specifically (e.g., regarding segmentation) per carried protocol. That 
is just a fact, and not
an implementation issue.
>
> I checked their documentation, which includes smoothing that looks a 
> little like an Internet Draft:
> http://tipc.io/protocol.html
> but it’s quite confusing. Taken at face value, they make their own 
> argument that IP addresses won’t work - at which point running raw 
> over IP serves no utility (sec 3.1.1),
That is not a correct interpretation of the text. There is nowhere 
stated that IP addresses won't work for TIPC,
neither in sec. 3.1.1 or anywhere else. Of course they work, *for 
transport purposes*, just like they have been
doing for many years already when running TIPC over UDP. What we state 
elsewhere in the document is that
IP addresses are no good in the *user API*, because they are location 
bound.
That is also why DNS was invented, I  believe.

We also state that using IP addresses is less optimal than omitting the 
IP layer altogether
and using MAC addresses, but that doesn't mean the former are useless, 
-it just makes
IP the only viable alternative in the cases when a network owner doesn't 
allow non-IP
protocols though their back planes, or when routing gets involved.

> even though most of those claims are debatable (DNS-SD is too static? 
> And expensive?? How so?). Then they reinvent the DNS in Section 6.
There is no doubt that DNS is not the best choice for the type of 
environments (tight clusters) where
we use TIPC. All DNS implementations I know run in user land, and doing 
a service discovery typically
means at least one, and often several inter-process and potentially 
inter-node hops. Even if there is
a process local lookup cache in each sender, that cache has to be 
populated before it is of any use.
Instead, TIPC uses a tailor-made kernel resident translation service 
which normally contains a complete
copy of the the lookup database, so there are no unnecessary hops and no 
cache misses.

This would have been of less importance if TIPC were only a connection 
oriented TCP-like service where
service lookup is only needed at connection setup. But a just as 
important feature of TIPC is its reliable
connectionless transport mode. Here, the lookup service is not primarily 
about service discovery
(although that is also important), but about efficient on-the-fly 
translation between user level service
addresses (aka "port names") and location bound socket addresses (aka 
"port identities"). This
translation has to be performed per message, not per connection, since 
the destination may change
between each message.

If we were to make an analogy with the IP world, we could imagine that 
we use UDP to send high
volume traffic to many different destinations, each having its own 
domain name. Making a
separate DNS lookup for each sent message would certainly work, but it 
would not by far be as
performant as having a tailor made "always cache resident" translation 
table, shared between
all processes, like we do in TIPC.

Furthermore, when the connectionless service is used, sockets might be 
created/deleted and
bound/unbound at extremely high rates, much higher than DNS with its 
hierarchical updates
is meant to deal with. This is what we mean with DNS being too "static". 
It is not saying that
DNS is bad, it is just stating that it is not designed for the very high 
performance requirements
and dynamism we have in TIPC.

There is no doubt that a few things in TIPC could have been done 
differently,  but the decision
to design our own topology/lookup service is not among those. This 
request is an attempt to
open up for moving beyond some current limitations, e.g., by enabling 
introduction of a more
versatile 128-bit  service addressing concept.  Along with this request 
we are aiming at having
an updated version of the protocol description adopted as an 
informational RFC, so that
TIPC can be regarded as an IETF supported protocol in its own right.

Whatever the viewpoints, TIPC is currently what it is, and rather than 
focusing on the motivation
for certain implementation choices and how they work, I think IETF 
should consider the fact
that this is a well-established service used by dozens of small and big 
companies, running high-volume
traffic at hundreds of telco sites around the globe. They should also 
consider that TIPC has
existed as a stable and well-maintained implementation in all major 
Linux distros for many years.

IETF now has a genuine chance to help us making TIPC even more useful 
for existing and new users.

BR
Jon Maloy

>
> Frankly, IMO this would probably have a difficult time arguing for a 
> transport protocol port number, much less an IP protocol number.
>
> Joe
>
>
>> On Mar 17, 2020, at 3:34 PM, Suresh Krishnan <[e-mail] 
>> <mailto:[e-mail]>> wrote:
>>
>> Hi all,
>>   IANA received an IP protocol number allocation request from Jon 
>> Maloy <[e-mail] <mailto:[e-mail]>> for the 
>> Transparent Inter Process Communication (TIPC) protocol. I picked up 
>> this request as Internet AD as the registration procedure requires 
>> IESG Approval. I had provided the information below to the IESG and 
>> discussed this with a favorable view of this request. I am 
>> recommending allocation of an IP protocol number for this. If you 
>> have any concerns that you think I might have overlooked, please let 
>> me know by end of day March 24 2020.
>>
>> After several round trips of back and forth probing I had collected 
>> the following information regarding the protocol number request for 
>> TIPC. There were two main questions I had for him:
>>
>> * Q1: Why did they want an IP protocol number?
>> * Q2: Is the protocol implemented and deployed widely?
>>
>> Q1: Why did they want an IP protocol number?
>> ====================================
>>
>> There are two main reasons why they want to reserve an IP protocol 
>> number:
>>
>> 1)  Performance
>> They are currently working on adding GSO support to TIPC, including a 
>> TSO-like "full-size buffer pass-thru" though virtio and the host OS 
>> tap interface. They have experimentally implemented GSO across UDP 
>> tunnels, but performance is not good because of the way the tunnel 
>> GSO is implemented, and there is no 'pass-thru' support for this in 
>> Linux. They have even done the same at the pure L2 level, but L2 
>> transport is sometimes not accepted by the cloud maintainers or the 
>> telco operators, and hence they need an alternative. The best 
>> alternative, both from a performance and acceptability viewpoint 
>> would be to establish TIPC as a full-fledged IP protocol, apart from 
>> the traditional L2 bearer many users are still using.
>>
>> 2) Currently TIPC has two user address types:
>>
>> struct tipc_service_addr{
>>     uint32_t type;
>>     uint32_t instance;
>>     uint32_t node;
>> };
>> struct tipc_service_addr{
>>     uint32_t port;
>>     uint32_t node;
>> };
>>
>> They want to complement this  with a new API where we have a unified 
>> address type:
>> struct tipc_addr{
>>    u8 type[16];
>>    u8 instance[16];
>>    u8 node[16];
>> };
>>
>> This would give a 128-bit value range for both 'type', 'instance' and 
>> 'node', and opens up for new opportunities:
>> - Users will never need to coordinate 'type' values since there will 
>> no risk of collisions.
>> - Users can put whatever they want into the fields, e.g., an IPv6 
>> address, a Kubernetes or Docker container id, a LUKS disk UUID or 
>> just a plain string.
>> For the 'node' id this has already been implemented and released, but 
>> it is not reflected in the API yet.
>>
>> For the API extension they need a new IPPROTO_TIPC socket type which 
>> can be registered and instantiated independently from the traditional 
>> AF_TIPC socket type.
>>
>> You can find more info about this at http://tipc.io
>>
>> Q2: Is the protocol implemented and deployed widely?
>> ==========================================
>>
>> The requester provided the following information when I asked about 
>> who was currently using TIPC (pretty much about adoption and deployment):
>>
>> I can give you a list of current or recently active code contributors 
>> and companies/people who have been asking for support:
>>
>> Huawei:
>> For natural reasons I don't know any details about them, I can only 
>> name persons I have seen contributing to netdev or being active on 
>> our mailing lists. Huawei people sometimes use gmail addresses when 
>> posting questions and patches, so there are more persons than I have 
>> listed here.
>> Dmitry Kolmakov <[e-mail] 
>> <mailto:[e-mail]>>
>> Ji Qin <[e-mail] <mailto:[e-mail]>>
>> Wei Yongjun <[e-mail] <mailto:[e-mail]>>
>> <[e-mail] <mailto:[e-mail]>>
>> Yue Haibing <[e-mail] <mailto:[e-mail]>>
>> Junwei Hu <[e-mail] <mailto:[e-mail]>>
>> Jie Liu <[e-mail] <mailto:[e-mail]>>
>> Qiang Ning <[e-mail] <mailto:[e-mail]>>
>> Zhiqiang Liu <[e-mail] <mailto:[e-mail]>>
>> Miaohe Lin <[e-mail] <mailto:[e-mail]>>
>> Wang Wang <[e-mail] <mailto:[e-mail]>>
>> Kang Zhou <[e-mail] <mailto:[e-mail]>>
>> Suanming Mou <[e-mail] <mailto:[e-mail]>>
>>
>> Hu Junwei is the one I see most active at the moment.
>>
>> Nokia:
>> Tommi Rantala <[e-mail] 
>> <mailto:[e-mail]>>
>>
>> Verizon:
>> Amar Nv <amar.nv@in..verizon.com <mailto:[e-mail]>>
>> Jayaraj Wilson, <[e-mail] 
>> <mailto:[e-mail]>>
>>
>> Hewlett Packard Enterprise:
>> <[e-mail] <mailto:[e-mail]>>
>>
>> WindRiver:
>> Ying Xue <[e-mail] <mailto:[e-mail]>>
>> He is my co-maintainer at netdev ans sourcefoge.
>> Windriver has several products in the field based on TIPC, e.g. 
>> control system for Sikorsky helicopters.
>>
>> Orange:
>> Christophe JAILLET <[e-mail] 
>> <mailto:[e-mail]>>
>>
>> Redhat:
>> The person contacting me to have TIPC integrated and maintained in 
>> RHEL-8.0 was
>> Sirius Rayner-Karlsson <[e-mail] 
>> <mailto:[e-mail]>>
>> He motivated it with a request from "a telco vendor", but I don't 
>> know which one.
>> Hence, TIPC is now integrated in and officially supported from RHEL 8.1
>>
>> ABB:
>> https://new.abb.com/pl
>> Mikolaj K. Chojnacki <[e-mail] 
>> <mailto:[e-mail]>>
>> Krzysztof Rybak <[e-mail] 
>> <mailto:[e-mail]>>
>>
>> Ericsson:
>> All (dozens of) applications based on the TSP and Core 
>> Middleware/Components Based Architecture (CMW/CBA) platforms is per 
>> definition based on TIPC. They have not yet started to use TIPC on 
>> their Kubernetes based ADP platform, but there is work ongoing on this.
>>
>> I also see numerous other people being active, from small (I believe) 
>> companies, universities and private contributors. E.g.,
>> Innovsys Inc http://www.innovsys.com/innovsys/
>> Allied Telesis https://www.alliedtelesis.com/
>> Telaverge Communications http://www.telaverge.com/
>> Ivan Serdyuk <[e-mail] 
>> <mailto:[e-mail]>> (seems to be responsible for 
>> the ZeroMQ port of TIPC)
>> John Hopkins University / Fast LTA, Munich 
>> <[e-mail] <mailto:[e-mail]>>
>> Just to mention a few...
>>
>> TIPC is currently maintained jointly by Ericsson, WindRiver, Redhat, 
>> and the Australian consulting company DEK Technologies 
>> https://www.dektech.com.au/
>>
>> Thanks
>> Suresh
>>
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