From: "Jürgen Lambrecht" <j.lambrecht@televic.com>
To: Vinicius Costa Gomes <vinicius.gomes@intel.com>,
"Allan W. Nielsen" <allan.nielsen@microchip.com>
Cc: Horatiu Vultur <horatiu.vultur@microchip.com>,
linux-kernel@vger.kernel.org, netdev@vger.kernel.org,
bridge@lists.linux-foundation.org, jiri@resnulli.us,
ivecera@redhat.com, davem@davemloft.net,
roopa@cumulusnetworks.com, nikolay@cumulusnetworks.com,
anirudh.venkataramanan@intel.com, olteanv@gmail.com,
andrew@lunn.ch, jeffrey.t.kirsher@intel.com,
UNGLinuxDriver@microchip.com
Subject: Re: [RFC net-next v3 00/10] net: bridge: mrp: Add support for Media Redundancy Protocol (MRP)
Date: Tue, 28 Jan 2020 11:35:34 +0100 [thread overview]
Message-ID: <83f98a49-d5b6-c5d8-9ca3-4c5eea8fb312@televic.com> (raw)
In-Reply-To: <87imkz1bhq.fsf@intel.com>
On 1/25/20 10:18 PM, Vinicius Costa Gomes wrote:
> CAUTION: This Email originated from outside Televic. Do not click links or open attachments unless you recognize the sender and know the content is safe.
>
>
> Hi,
>
> "Allan W. Nielsen" <allan.nielsen@microchip.com> writes:
>
>> Hi Vinicius,
>>
>> On 24.01.2020 13:05, Vinicius Costa Gomes wrote:
>>> I have one idea and one question.
>> Let me answer the question before dicussing the idea.
>>
>>> The question that I have is: what's the relation of IEC 62439-2 to IEEE
>>> 802.1CB?
>> HSR and 802.1CB (often called FRER - Frame Replication and Elimination
>> for Reliability) shares a lot of functionallity. It is a while since I
>> read the 802.1CB standard, and I have only skimmed the HSR standard, but
>> as far as I understand 802.1CB is a super set of HSR. Also, I have not
>> studdied the HSR implementation.
>> Both HSR and 802.1CB replicate the frame and eliminate the additional
>> copies. If just 1 of the replicated fraems arrives, then higher layer
>> applications will not see any traffic lose.
>>
>> MRP is different, it is a ring protocol, much more like ERPS defined in
>> G.8032 by ITU. Also, MRP only make sense in switches, it does not make
>> sense in a host (like HSR does).
>>
>> [snip MPR explanation]
>>
>> Sorry for the long explanation, but it is important to understand this
>> when discussion the design.
> Not at all, thanks a lot. Now it's clear to me that MRP and 802.1CB are
> really different beasts, with different use cases/limitations:
>
> - MRP: now that we have a ring, let's break the loop, and use the
> redudancy provided by the ring to detect the problem and "repair" the
> network if something bad happens;
indeed. MRP is IEC 62439-2
>
> - 802.1CB: now that we have a ring, let's send packets through
> two different paths, and find a way to discard duplicated ones, so
> even if something bad happens the packet will reach its destination;
Not exactly, 802.1CB is independent of the network layout, according to the abstract on https://ieeexplore.ieee.org/document/8091139.
The IEC 62439-3 standard mentions 2 network layouts: 2 parallel paths and a ring:
- IEC 62439-3.4 Parallel Redundancy Protocol (PRP): this runs on 2 separated parallel paths in the network
- IEC 62439-3.5 HSR (High availability seamless redundancy): this runs on a ring: each host sends all data in 2 directions, and when it receives its own data back, it discards it (to avoid a loop).
(and it is better to implement IEEE, because the standard costs only 151$, and the IEC ones cost 2x410$)
Kind regards,
Jürgen
next prev parent reply other threads:[~2020-01-28 10:35 UTC|newest]
Thread overview: 56+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-24 16:18 [RFC net-next v3 00/10] net: bridge: mrp: Add support for Media Redundancy Protocol (MRP) Horatiu Vultur
2020-01-24 16:18 ` [RFC net-next v3 01/10] net: bridge: mrp: Expose mrp attributes Horatiu Vultur
2020-01-24 16:18 ` [RFC net-next v3 02/10] net: bridge: mrp: Expose function br_mrp_port_open Horatiu Vultur
2020-01-24 17:37 ` Andrew Lunn
2020-01-25 11:29 ` Horatiu Vultur
2020-01-24 16:18 ` [RFC net-next v3 03/10] net: bridge: mrp: Add MRP interface used by netlink Horatiu Vultur
2020-01-24 17:43 ` Andrew Lunn
2020-01-25 11:37 ` Horatiu Vultur
2020-01-25 15:20 ` Andrew Lunn
2020-01-25 19:16 ` Allan W. Nielsen
2020-01-26 13:28 ` Horatiu Vultur
2020-01-26 15:39 ` Andrew Lunn
2020-02-20 9:08 ` Nikolay Aleksandrov
2020-02-20 13:00 ` Allan W. Nielsen
2020-01-24 16:18 ` [RFC net-next v3 04/10] net: bridge: mrp: Add generic netlink interface to configure MRP Horatiu Vultur
2020-01-25 15:34 ` Andrew Lunn
2020-01-25 19:28 ` Allan W. Nielsen
2020-01-26 13:39 ` Horatiu Vultur
2020-01-24 16:18 ` [RFC net-next v3 05/10] net: bridge: mrp: Update MRP interface to add switchdev support Horatiu Vultur
2020-01-24 16:18 ` [RFC net-next v3 06/10] net: bridge: mrp: switchdev: Extend switchdev API to offload MRP Horatiu Vultur
2020-01-25 16:35 ` Andrew Lunn
2020-01-26 13:22 ` Horatiu Vultur
2020-01-26 15:59 ` Andrew Lunn
2020-01-27 11:04 ` Allan W. Nielsen
2020-01-27 14:41 ` Jürgen Lambrecht
[not found] ` <c5733ddb-a837-b866-54bf-c631baf36c54@televic.com>
2020-01-27 15:06 ` Andrew Lunn
2020-01-28 9:50 ` Jürgen Lambrecht
2020-01-27 11:29 ` Jürgen Lambrecht
2020-01-27 12:27 ` Allan W. Nielsen
2020-01-27 14:39 ` Jürgen Lambrecht
2020-01-28 9:58 ` Allan W. Nielsen
2020-01-24 16:18 ` [RFC net-next v3 07/10] net: bridge: mrp: switchdev: Implement MRP API for switchdev Horatiu Vultur
2020-01-24 16:18 ` [RFC net-next v3 08/10] net: bridge: mrp: Connect MRP api with the switchev API Horatiu Vultur
2020-01-24 16:18 ` [RFC net-next v3 09/10] net: bridge: mrp: Integrate MRP into the bridge Horatiu Vultur
2020-01-25 15:42 ` Andrew Lunn
2020-01-26 12:49 ` Horatiu Vultur
2020-01-25 16:16 ` Andrew Lunn
2020-01-26 13:01 ` Horatiu Vultur
2020-01-26 17:12 ` Andrew Lunn
2020-01-27 10:57 ` Allan W. Nielsen
2020-01-27 13:02 ` Horatiu Vultur
2020-01-27 13:40 ` Andrew Lunn
2020-01-28 9:56 ` Jürgen Lambrecht
2020-01-28 10:17 ` Allan W. Nielsen
2020-01-24 16:18 ` [RFC net-next v3 10/10] net: bridge: mrp: Update Kconfig and Makefile Horatiu Vultur
2020-01-24 20:34 ` [RFC net-next v3 00/10] net: bridge: mrp: Add support for Media Redundancy Protocol (MRP) Allan W. Nielsen
2020-01-24 21:05 ` Vinicius Costa Gomes
2020-01-25 9:44 ` Allan W. Nielsen
2020-01-25 16:23 ` Andrew Lunn
2020-01-25 19:12 ` Allan W. Nielsen
2020-01-25 21:18 ` Vinicius Costa Gomes
2020-01-28 10:35 ` Jürgen Lambrecht [this message]
2020-02-18 12:18 ` Allan W. Nielsen
2020-02-18 16:55 ` Jakub Kicinski
2020-02-20 10:48 ` Nikolay Aleksandrov
2020-02-20 12:58 ` Allan W. Nielsen
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=83f98a49-d5b6-c5d8-9ca3-4c5eea8fb312@televic.com \
--to=j.lambrecht@televic.com \
--cc=UNGLinuxDriver@microchip.com \
--cc=allan.nielsen@microchip.com \
--cc=andrew@lunn.ch \
--cc=anirudh.venkataramanan@intel.com \
--cc=bridge@lists.linux-foundation.org \
--cc=davem@davemloft.net \
--cc=horatiu.vultur@microchip.com \
--cc=ivecera@redhat.com \
--cc=jeffrey.t.kirsher@intel.com \
--cc=jiri@resnulli.us \
--cc=linux-kernel@vger.kernel.org \
--cc=netdev@vger.kernel.org \
--cc=nikolay@cumulusnetworks.com \
--cc=olteanv@gmail.com \
--cc=roopa@cumulusnetworks.com \
--cc=vinicius.gomes@intel.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).