Re: [netconf] Capability-fetching mechanisms

"maqiufang (A)" <maqiufang1@huawei.com> Wed, 12 May 2021 06:54 UTC

Return-Path: <maqiufang1@huawei.com>
X-Original-To: netconf@ietfa.amsl.com
Delivered-To: netconf@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id CDCEA3A374B for <netconf@ietfa.amsl.com>; Tue, 11 May 2021 23:54:51 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.899
X-Spam-Level:
X-Spam-Status: No, score=-1.899 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, HTML_MESSAGE=0.001, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=-0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001] autolearn=ham autolearn_force=no
Received: from mail.ietf.org ([4.31.198.44]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id PzAN7HmhuPaJ for <netconf@ietfa.amsl.com>; Tue, 11 May 2021 23:54:47 -0700 (PDT)
Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 8F3283A374A for <netconf@ietf.org>; Tue, 11 May 2021 23:54:46 -0700 (PDT)
Received: from fraeml743-chm.china.huawei.com (unknown [172.18.147.206]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4Fg4xS1TbSz6tmqx for <netconf@ietf.org>; Wed, 12 May 2021 14:43:24 +0800 (CST)
Received: from dggeml751-chm.china.huawei.com (10.1.199.150) by fraeml743-chm.china.huawei.com (10.206.15.224) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256) id 15.1.2176.2; Wed, 12 May 2021 08:54:41 +0200
Received: from dggeme770-chm.china.huawei.com (10.3.19.116) by dggeml751-chm.china.huawei.com (10.1.199.150) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2176.2; Wed, 12 May 2021 14:54:39 +0800
Received: from dggeme770-chm.china.huawei.com ([10.8.68.58]) by dggeme770-chm.china.huawei.com ([10.8.68.58]) with mapi id 15.01.2176.012; Wed, 12 May 2021 14:54:39 +0800
From: "maqiufang (A)" <maqiufang1@huawei.com>
To: Wei Wang <weiwang94@foxmail.com>, Qin Wu <bill.wu@huawei.com>, Kent Watsen <kent+ietf@watsen.net>
CC: "netconf@ietf.org" <netconf@ietf.org>
Thread-Topic: [netconf] Capability-fetching mechanisms
Thread-Index: AddG0HdnSNhQPyUmB0iwqeRmQPitBf//uS2A//9kl9A=
Date: Wed, 12 May 2021 06:54:39 +0000
Message-ID: <3a058efa22df47239b8d016c6ba9e431@huawei.com>
References: <fe4d6fca7cc34ffc8611bf0c94352b33@huawei.com> <tencent_1EAAB36DA33D542F6FEE723E8ECD21533405@qq.com>
In-Reply-To: <tencent_1EAAB36DA33D542F6FEE723E8ECD21533405@qq.com>
Accept-Language: zh-CN, en-US
Content-Language: zh-CN
X-MS-Has-Attach:
X-MS-TNEF-Correlator:
x-originating-ip: [10.136.123.93]
Content-Type: multipart/alternative; boundary="_000_3a058efa22df47239b8d016c6ba9e431huaweicom_"
MIME-Version: 1.0
X-CFilter-Loop: Reflected
Archived-At: <https://mailarchive.ietf.org/arch/msg/netconf/lRldvV8MYU5LY0XLJXLWmkHf7Xc>
Subject: Re: [netconf] Capability-fetching mechanisms
X-BeenThere: netconf@ietf.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: NETCONF WG list <netconf.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/netconf>, <mailto:netconf-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/netconf/>
List-Post: <mailto:netconf@ietf.org>
List-Help: <mailto:netconf-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/netconf>, <mailto:netconf-request@ietf.org?subject=subscribe>
X-List-Received-Date: Wed, 12 May 2021 06:54:52 -0000

Hi, folks,

Since data-export-capability draft defines a mechanism to discover a set of capabilities supported by the NETCONF/RESTCONF server(the network device, actually).

But in the http-notif draft, what we need to discover is the receiver's capabilities, rather than the device’s.

So I think the reason Kent said that the receiver must also be a NETCONF and/or RESTCONF server is that only in this case can the data-export-capability draft be used as capability discovery on the http-receiver side.

Please correct me if there exists any misunderstanding.-:)

From my perspective, The data-export-capability does not have to require the receiver to function as a NETCONF/RESTCONF server. The capability discovery mechanism in these two drafts can complement each other in this case. In other cases, data-export-capability provides the receiver with an overall  acquisition of the transport capabilities about the device.


From: netconf [mailto:netconf-bounces@ietf.org] On Behalf Of Wei Wang
Sent: Wednesday, May 12, 2021 1:32 PM
To: Qin Wu <bill.wu@huawei.com>om>; Kent Watsen <kent+ietf@watsen.net>et>; netconf@ietf.org
Subject: Re: [netconf] Capability-fetching mechanisms

Hi, Qin and kent:

    Thanks for clarification, I feel it will be useful to have one common model to support both pull and push approach and help both the server and client know each other’s capability.

Wei
China Telecom

------------------ Original ------------------
From: "Qin Wu" <bill.wu@huawei.com<mailto:bill.wu@huawei.com>>;
Date: Wed, May 12, 2021 09:51 AM
To: "Kent Watsen"<kent+ietf@watsen.net<mailto:kent+ietf@watsen.net>>;"netconf@ietf.org<mailto:netconf@ietf.org>"<netconf@ietf.org<mailto:netconf@ietf.org>>;
Subject: Re: [netconf] Capability-fetching mechanisms

Hi, Kent:
Sorry for late follow up.
On Apr 19, 2021, at 5:39 PM, Kent Watsen <kent@watsen.net<mailto:kent@watsen.net>> wrote:

Dear WG,

One of the outcomes from “https-notif” presentation during the NETCONF 110 session was to what extent all the notif (e.g., https, udp, etc.) drafts should define their own capability-fetching mechanism, or use the mechanism defined by the "data-export-capabilities” draft.

As authors, Mahesh and I discussed some of the PROs and CONs of the approaches as follows:
[Qin]:I am under impression that shared-mechanism has a lot of benefit.:-)

  *   PROs (for having a shared-mechanism):

     *   Enables a common mechanism spanning multiple notif transports to exist

  *   CONs (against having a shared mechanism):

     *   Entails each receiver also needing to be a NETCONF and/or RESTCONF server
                                [Qin]:Is receiver in this context NETCONF/RESTCONF server or client?
                                  I think we mix two things,

a.      one is the server advertise its capability to the client , (i.e., server capability advertisement)

b.      the other is server send the capability query request the client and get capability response from the client. (client capability fetching)
                                I think data-export-capabilities right now focuses on (a), the question you ask here is whether (b) can be defined as shared mechanism which can be part of
                                the "data-export-capabilities” draft. If my understanding is correct, I think it will be nice to have (b) such shared mechanism, i.e., Defining (a) and (b) in a single place.

        *   Whereas a notif-specific solution can be optimized on a per-protocol basis.
        *   FWIW, if RC, the receiver COULD minimally support *just* the single GET request (i.e., not a complete RC server)
        *   Still, networking/firewall would have to support the outbound NC/RC flow, in addition to the base notification flow
                   [Qin]: "data-export-capabilities " draft uses draft-ietf-netconf-notification-capabilities-16 as basis or foundation. If my understanding is correct, draft-ietf-netconf- notification-capabilities-16 doesn’t
require receiver to support NETCONF or   RESTCONF.

     *   Potentially extends the number of capabilities to be more than minimally necessary

        *   e.g., the current "data-export-capabilities” modules define dozens of capabilities supporting RFC 8639 and RFC 8641 that are not needed for https-notif,
                                     [Qin] Dozens of capabilities defined by the current "data-export-capabilities” modules are all optional capability. It doesn’t require all the capabilities to be supported.
when RFC 8639 is not in use.

           *   HTTPS-Notif seems to need only three capabilities:

              *   What encodings are supported (json, xml, binary)
              *   If the RFC 8639 state machine is supported.
              *   If bundled messages is supported.
                                  [Qin]: So HTTPs-notif can pick those three capabilities and ignore other capabilities.  I believe HTTP has mechanism to deal with these unhandled capabilities advertised by the network device.  One of such example is unhandled
Namespace defined in (https://datatracker.ietf.org/doc/html/draft-ietf-regext-unhandled-namespaces-07)

           *   Presumably, UDP-Notif would similarly have a small set of capacities.

              *   In fact, it may be less, as UDP may be unable to support RFC 8639
             [Qin]: See clarification above. For UDP notif, it doesn’t require all the capability to be supported.

Thoughts?

Kent and Mahesh  // as authors


_______________________________________________
netconf mailing list
netconf@ietf.org<mailto:netconf@ietf.org>
https://www.ietf.org/mailman/listinfo/netconf