無線網(Wi-Fi) 空中線(Antenna）(105) 802.1D/ 802.1Q

# 802.1D
IEEE 802.1D-1990 - Standard for Local and Metropolitan Area Networks: Media Access Control (MAC) Bridges
IEEE 802.1i-1992 - Standard for Local and Metropolitan Area Network MAC Bridges - Fibre Distributed Data Interface (FDDI) Supplement
IEEE 802.1j-1996 - Supplement to Information technology-Telecommunications and information exchange between systems- Local area networks-Media access control (MAC) bridges: Managed objects for MAC bridges

IEEE 802.1D-1998 - IEEE Standard for Local Area Network MAC (Media Access Control) Bridges
IEEE 802.1t-2001 - IEEE Standard for Information technology - Telecommunications and information exchange between systems - Local and metropolitan area networks - Common specifications - Part 3: Media Access Control (MAC) Bridges - Amendment 1: Technical and Editorial Corrections
IEEE 802.1w-2001 - IEEE Standard for Information Technology -Telecommunications and Information Exchange Between Systems - Local and Metropolitan Area Networks - Common Specifications - Part 3: Media Access Control (MAC) Bridges: Amendment 2 - Rapid Reconfiguration

IEEE 802.1D-2004 - IEEE Standard for Local and metropolitan area networks: Media Access Control (MAC) Bridges
IEEE 802.17a-2004 - IEEE Standard for Local and Metropolitan Area Networks: Media Access Control (MAC) Bridges - Amendment 1: Bridging of IEEE Std 802.17
IEEE 802.16k-2007 - IEEE Standard for Local and Metropolitan Area Networks: Media Access Control (MAC) Bridges - Amendment 2: Bridging of IEEE 802.16

# 802.1Q

IEEE 802.1Q-1998 - IEEE Standards for Local and Metropolitan Area Networks: Virtual Bridged Local Area Networks
IEEE 802.1u-2001 - IEEE Standard for Virtual Bridged Local Area Networks - Corrigendum 1: Technical and Editorial Corrections
IEEE 802.1s-2002 - IEEE Standards for Local and Metropolitan Area Networks - Amendment to 802.1Q Virtual Bridged Local Area Networks: Multiple Spanning Trees
IEEE 802.1v-2001 - IEEE Standard for Local and metropolitan area networks--Virtual Bridged Local Area Networks -- Amendment 2: VLAN Classification by Protocol and Port
IEEE 802.1ag-2007 - IEEE Standard for Local and Metropolitan Area Networks Virtual Bridged Local Area Networks Amendment 5: Connectivity Fault Management
IEEE 802.1ah-2008 - IEEE Standard for Local and metropolitan area networks -- Virtual Bridged Local Area Networks Amendment 7: Provider Backbone Bridges
IEEE 802.1aj-2009 - IEEE Standard for Local and Metropolitan Area Networks--Virtual Bridged Local Area Networks Amendment 11: Two-Port Media Access Control (Mac) Relay

IEEE Standards Interpretation for IEEE Std 802.1DTM-1999, IEEE Std 802.1QTM- 1998 and IEEE Std 802.3TM, 2000 Edition

>Interpretations are issued to explain and clarify the intent of a standard and do not con- stitute an alteration to the original standard. In addition, interpretations are not intend- ed to supply consulting information. Permission is hereby granted to download and print one copy of this document. Individuals seeking permission to reproduce and/or distrib- ute this document in its entirety or portions of this document must contact the IEEE Standards Department for the appropriate license. Use of the information contained in this document is at your own risk.
Topic: MAC behavior when it is attached to the 802.1D/Q Bridge
It is clear that IEEE 802.3 MAC may not send frames greater than 1518 bytes in length for untagged frame and 1522 bytes for a tagged (802.3ac) frame. It is also clear (from 4.2.4.2.1 a.) that Reception of a frame greater than these are allowed to be truncated (and reported as a error) but not required to do so.
In an implementation designed to meet IEEE 802.1D/Q Bridge with integrated IEEE 802.3 MAC, it may receive well-formed (correct frame format with valid FCS) frame that is “slightly“ longer than 1518/1522 bytes. It is desirable to allow these frames to be forwarded. However, simply by allowing these frames to be switched, does this imple- mentation violate this aspect of IEEE 802.3 MAC standard? One could argue that since
a frame reception does NOT enforce the frame size limit, it is acceptable to allow it to reach the bridge relay function, but on its egress, a MAC could send a frame that is lon- ger than the maximum MTU specified. But one could further argue that, so long as the implementation only generates longer frame if and only if it received one, the implemen- tation is still conformant in this respect. Please ignore the 4 bytes of 802.3ac/802.1Q tag generation/removal issue when answering this question. The reading of IEEE 802.1D Clause 6.3.8 allows any MTU to be supported and also allows for only supporting small- est common denominator between bridged LAN.
So what is not clear, and would like the clarification/interpretation of the clause 4.2.4.2.1 relative to 802.1D bridging, if a MAC receives frames longer than 1518/1522, otherwise well formed, and relays it to a egress port, and the egress port sends this frame, does the implementation violate the standard? Or this extended length support not covered by the standard? It would settle some internal debate if you could answer both questions  and provide any other helpful guidance for us.
Begin From IEEE 802.3-2000
4.2.4.2 Receive media access management 4.2.4.2.1 Framing The CSMA/CD sublayer recognizes the boundaries of an incoming frame by monitoring the receive Data-Valid signal provided by the Physical Layer. Two possible length errors can occur that indicate ill-framed data: the frame may be too long, or its length may not be an integer number of octets. a) Maximum Frame Size. The receiving CSMA/CD sublayer is not required to enforce the frame size limit, but it is allowed to truncate frames longer than maxUn- taggedFrameSize octets and report this event as an (implementation-dependent) error. A receiving CSMA/CD sublayer that supports tagged MAC frames (see 3.5) may similarly truncate frames longer than (maxUntaggedFrameSize + qTag- PreSize) octets in length, and report this event as an (implementation-dependent) error. b) Integer Number of Octets in Frame. Since the format of a valid frame specifies an integer number of oc- tets, only a collision or an error can produce a frame with a length that is not an inte- ger multiple of 8 bits. Complete frames (that is, not rejected as collision fragments; see 4.2.4.2.2) that do not contain an integer number of octets are truncated to the nearest octet boundary. If frame check sequence validation detects an error in such a frame, the status code alignmentError is reported.
Begin From IEEE 802.1-1998
Clause 6.3.8: The Maximum Service Data Unit Size that can be supported by an 802® LAN varies with the MAC method and its associated parameters (speed, electrical char- acteristics, etc.). It may be constrained by the owner of the LAN. The Maximum Service Data Unit Size supported by a Bridge between two LANs is the smaller of that supported by the LANs. No attempt is made by a Bridge to relay a frame to a LAN that does not support the size of Service Data Unit conveyed by that frame.
Interpretation Response - 802.1D-1999 & 802.1Q-1998 IEEE Std 802.1D states:
7.7.1 Enforcing topology restriction Each Port is selected as a potential transmission Port if, and only if a) The Port on which the frame was received was in a forwarding state (8.4), and b) The Port considered for transmission is in a forwarding state, and c) The Port considered for transmission is not the same as the Port on which the frame was received, and d) The size of the mac_service_data_unit conveyed by the frame does not exceed the maximum size of mac_service_data_unit supported by the LAN to which the Port considered for transmission is attached. For each Port not selected as a potential transmission Port, the frame shall be discarded.
A similar statement is made in 8.7.1 of IEEE Std 802.1Q. These clauses clearly require a conformant Bridge to discard, and not transmit, a frame that exceeds the maximum frame size supported by the transmitting MAC. In the context of this interpretation re- quest, the maximum frame size supported by an IEEE 802.3 MAC is defined in 3.2.7 of IEEE Std 802.3.
445 Hoes Lane, Piscataway, NJ 08854 USA • +1 732 981 0060 • +1 732 981 0027 • standards.ieee.org
The standard clearly states in 3.2.7 that the maximum frame size is 1518 (for untagged frames) or 1522 (for tagged frames).
A DTE (MAC plus MAC Client) that issues frames greater than the maximum frame size is not compliant.

IEEE 802.1Q-2005 - IEEE Standard for Local and Metropolitan Area Networks---Virtual Bridged Local Area Networks
IEEE 802.1Q-2005/Cor 1-2008 - IEEE Standard for Local and Metropolitan Area Networks - Virtual Bridged Local Area Networks - Corrigendum 1: Corrections to the Multiple Registration Portocol
IEEE 802.1ad-2005 - IEEE Standard for Local and Metropolitan Area Networks---Virtual Bridged Local Area Networks---Amendment 4: Provider Bridges
IEEE 802.1ap-2008 - IEEE Standard for Local and Metropolitan Area Networks -- Virtual Bridged Local Area Networks - Amendment 8: Management Information Base (MIB) Definitions for VLAN Bridges
IEEE 802.1Qat-2010 - IEEE Standard for Local and metropolitan area networks--Virtual Bridged Local Area Networks Amendment 14: Stream Reservation Protocol (SRP)
IEEE 802.1Qau-2010 - IEEE Standard for Local and Metropolitan Area Networks-- Virtual Bridged Local Area Networks Amendment 13: Congestion Notification
IEEE 802.1Qaw-2009 - IEEE Standard for Local and metropolitan area networks-- Virtual Bridged Local Area Networks Amendment 9: Management of Data Driven and Data Dependent Connectivity Faults
IEEE 802.1Qay-2009 - IEEE Standard for Local and metropolitan area networks-- Virtual Bridged Local Area Networks Amendment 10: Provider Backbone Bridge Traffic Engineering
IEEE 802.1Qav-2009 - IEEE Standard for Local and metropolitan area networks-- Virtual Bridged Local Area Networks Amendment 12: Forwarding and Queuing Enhancements for Time-Sensitive Streams
IEEE 802.20b-2010 - IEEE Standard for Local and metropolitan area networks--Virtual Bridged Local Area Networks - Amendment 15: Bridging of IEEE 802.20

IEEE 802.1Q-2011 - IEEE Standard for Local and metropolitan area networks--Media Access Control (MAC) Bridges and Virtual Bridged Local Area Networks
IEEE 802.1Q-2011/Cor 2-2012 - IEEE Standard for Local and metropolitan area networks--Media Access Control (MAC) Bridges and Virtual Bridged Local Area Networks--Corrigendum 2: Technical and editorial corrections
802.1aq-2012
802.1Qbb-2011
802.1Qbc-2011
802.1Qbe-2011
802.1Qbf-2011
802.1Qaz-2011
802.1Qbg-2012
802.1Qbp-2014
802.1Qbu-2016
802.1Qbz-2016
802.1Qca-2015
802.1Qcc-2018
802.1Qcd-2015
802.1Qbv-2015
802.1Qch-2017
IEEE 802.1Q-2014 - IEEE Standard for Local and metropolitan area networks--Bridges and Bridged Networks
IEEE 802.1Q-2014/Cor 1-2015 - IEEE Standard for Local and metropolitan area networks--Bridges and Bridged Networks--Corrigendum 1: Technical and editorial corrections
IEEE 802.1Qci-2017 - IEEE Standard for Local and metropolitan area networks--Bridges and Bridged Networks--Amendment 28: Per-Stream Filtering and Policing
IEEE 802.1Qcp-2018 - IEEE Standard for Local and metropolitan area networks--Bridges and Bridged Networks--Amendment 30: YANG Data Model

IEEE 802.1Q-2018 - IEEE Standard for Local and Metropolitan Area Networks—Bridges and Bridged Networks

## Engineering Festa 2024前に必読記事一覧
登壇直後版 色使い(JIS安全色) Qiita Engineer Festa 2023〜私しか得しないニッチな技術でLT〜 スライド編 0.15
https://qiita.com/kaizen_nagoya/items/f0d3070d839f4f735b2b

プログラマが知っていると良い「公序良俗」
https://qiita.com/kaizen_nagoya/items/9fe7c0dfac2fbd77a945

逆も真：社会人が最初に確かめるとよいこと。OSEK(69)、Ethernet(59)
https://qiita.com/kaizen_nagoya/items/39afe4a728a31b903ddc

統計の嘘。仮説（127）
https://qiita.com/kaizen_nagoya/items/63b48ecf258a3471c51b

自分の言葉だけで論理展開できるのが天才なら、文章の引用だけで論理展開できるのが秀才だ。仮説（136）
https://qiita.com/kaizen_nagoya/items/97cf07b9e24f860624dd

参考文献駆動執筆(references driven writing)・デンソークリエイト編
https://qiita.com/kaizen_nagoya/items/b27b3f58b8bf265a5cd1

「何を」よりも「誰を」。１０年後のために今見習いたい人たち
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Qiitaの記事に３段階または５段階で到達するための方法
https://qiita.com/kaizen_nagoya/items/6e9298296852325adc5e

出力(output)と呼ばないで。これは状態(state)です。
https://qiita.com/kaizen_nagoya/items/80b8b5913b2748867840

coding (101) 一覧を作成し始めた。omake:最近のQiitaで表示しない5つの事象
https://qiita.com/kaizen_nagoya/items/20667f09f19598aedb68

あなたは「勘違いまとめ」から、勘違いだと言っていることが勘違いだといくつ見つけられますか。人間の間違い(human error(125))の種類と対策
https://qiita.com/kaizen_nagoya/items/ae391b77fffb098b8fb4

プログラマの「プログラムが書ける」思い込みは強みだ。３つの理由。仮説（168）統計と確率(17) , OSEK(79)
https://qiita.com/kaizen_nagoya/items/bc5dd86e414de402ec29

出力(output)と呼ばないで。これは状態(state)です。
https://qiita.com/kaizen_nagoya/items/80b8b5913b2748867840

これからの情報伝達手段の在り方について考えてみよう。炎上と便乗。
https://qiita.com/kaizen_nagoya/items/71a09077ac195214f0db

ISO/IEC JTC1 SC7 Software and System Engineering
https://qiita.com/kaizen_nagoya/items/48b43f0f6976a078d907

アクセシビリティの知見を発信しよう！（再び）
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統計論及確率論輪講（再び）
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読者の心をグッと惹き寄せる7つの魔法
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「@kazuo_reve 新人の方によく展開している有益な情報」確認一覧
https://qiita.com/kaizen_nagoya/items/b9380888d1e5a042646b

ソースコードで議論しよう。日本語で議論するの止めましょう（あるプログラミング技術の議論報告）
https://qiita.com/kaizen_nagoya/items/8b9811c80f3338c6c0b0

脳内コンパイラの3つの危険
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心理学の本を読むよりはコンパイラ書いた方がよくね。仮説（34）
https://qiita.com/kaizen_nagoya/items/fa715732cc148e48880e

NASAを超えるつもりがあれば読んでください。
https://qiita.com/kaizen_nagoya/items/e81669f9cb53109157f6

データサイエンティストの気づき!「勉強して仕事に役立てない人。大嫌い!!」『それ自分かも?』ってなった!!! 
https://qiita.com/kaizen_nagoya/items/d85830d58d8dd7f71d07

「ぼくの好きな先生」「人がやらないことをやれ」プログラマになるまで。仮説（37）　
https://qiita.com/kaizen_nagoya/items/53e4bded9fe5f724b3c4

なぜ経済学徒を辞め、計算機屋になったか（経済学部入学前・入学後・卒業後対応） 転職(1)  
https://qiita.com/kaizen_nagoya/items/06335a1d24c099733f64    

プログラミング言語教育のXYZ。 仮説（52） 
https://qiita.com/kaizen_nagoya/items/1950c5810fb5c0b07be4

【24卒向け】9ヶ月後に年収１０００万円を目指す。二つの関門と三つの道。
https://qiita.com/kaizen_nagoya/items/fb5bff147193f726ad25

「【25卒向け】Qiita Career Meetup for STUDENT」予習の勧め
https://qiita.com/kaizen_nagoya/items/00eadb8a6e738cb6336f

大学入試不合格でも筆記試験のない大学に入って卒業できる。卒業しなくても博士になれる。
https://qiita.com/kaizen_nagoya/items/74adec99f396d64b5fd5

全世界の不登校の子供たち「博士論文」を書こう。世界子供博士論文遠隔実践中心 安全(99)
https://qiita.com/kaizen_nagoya/items/912d69032c012bcc84f2

小川メソッド　覚え（書きかけ）
https://qiita.com/kaizen_nagoya/items/3593d72eca551742df68

DoCAP（ドゥーキャップ）って何ですか？
https://qiita.com/kaizen_nagoya/items/47e0e6509ab792c43327

views 20,000越え自己記事一覧
https://qiita.com/kaizen_nagoya/items/58e8bd6450957cdecd81

Views１万越え、もうすぐ１万記事一覧 最近いいねをいただいた213記事
https://qiita.com/kaizen_nagoya/items/d2b805717a92459ce853

# 関連資料
' @kazuo_reve 私が効果を確認した「小川メソッド」
https://qiita.com/kazuo_reve/items/a3ea1d9171deeccc04da

' @kazuo_reve 新人の方によく展開している有益な情報
https://qiita.com/kazuo_reve/items/d1a3f0ee48e24bba38f1

' @kazuo_reve Vモデルについて勘違いしていたと思ったこと
https://qiita.com/kazuo_reve/items/46fddb094563bd9b2e1e

# 自己記事一覧
Qiitaで逆リンクを表示しなくなったような気がする。時々、スマフォで表示するとあらわっることがあり、完全に削除したのではなさそう。

４月以降、せっせとリンクリストを作り、統計を取って確率を説明しようとしている。
2025年２月末を目標にしている。

物理記事　上位100
https://qiita.com/kaizen_nagoya/items/66e90fe31fbe3facc6ff

量子(0) 計算機, 量子力学 
https://qiita.com/kaizen_nagoya/items/1cd954cb0eed92879fd4

数学関連記事１００
https://qiita.com/kaizen_nagoya/items/d8dadb49a6397e854c6d

統計(0)一覧
https://qiita.com/kaizen_nagoya/items/80d3b221807e53e88aba

図(0) state, sequence and timing. UML and お絵描き 
https://qiita.com/kaizen_nagoya/items/60440a882146aeee9e8f

品質一覧 
https://qiita.com/kaizen_nagoya/items/2b99b8e9db6d94b2e971

言語・文学記事　１００
https://qiita.com/kaizen_nagoya/items/42d58d5ef7fb53c407d6

医工連携関連記事一覧
https://qiita.com/kaizen_nagoya/items/6ab51c12ba51bc260a82

自動車　記事　１００
https://qiita.com/kaizen_nagoya/items/f7f0b9ab36569ad409c5

通信記事１００
https://qiita.com/kaizen_nagoya/items/1d67de5e1cd207b05ef7

日本語（０）一欄
https://qiita.com/kaizen_nagoya/items/7498dcfa3a9ba7fd1e68

英語(0) 一覧
https://qiita.com/kaizen_nagoya/items/680e3f5cbf9430486c7d

転職(0)一覧
https://qiita.com/kaizen_nagoya/items/f77520d378d33451d6fe

仮説（0）一覧（目標100現在40）
https://qiita.com/kaizen_nagoya/items/f000506fe1837b3590df

音楽　一覧(0) 
https://qiita.com/kaizen_nagoya/items/b6e5f42bbfe3bbe40f5d

「@kazuo_reve 新人の方によく展開している有益な情報」確認一覧 
https://qiita.com/kaizen_nagoya/items/b9380888d1e5a042646b

Qiita(0)Qiita関連記事一覧（自分）
https://qiita.com/kaizen_nagoya/items/58db5fbf036b28e9dfa6

鉄道（０）鉄道のシステム考察はてっちゃんがてつだってくれる
https://qiita.com/kaizen_nagoya/items/26bda595f341a27901a0

安全（0）安全工学シンポジウムに向けて: 21
https://qiita.com/kaizen_nagoya/items/c5d78f3def8195cb2409

一覧の一覧( The directory of directories of mine.) Qiita(100)
https://qiita.com/kaizen_nagoya/items/7eb0e006543886138f39

Ethernet 記事一覧　Ethernet(0)
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Wireshark 一覧 wireshark(0)、Ethernet(48) 
https://qiita.com/kaizen_nagoya/items/fbed841f61875c4731d0

線網（Wi-Fi）空中線(antenna)(0) 記事一覧(118/300目標)
https://qiita.com/kaizen_nagoya/items/5e5464ac2b24bd4cd001

OSEK OS設計の基礎　OSEK(100)
https://qiita.com/kaizen_nagoya/items/7528a22a14242d2d58a3

Error一覧 error(0)
https://qiita.com/kaizen_nagoya/items/48b6cbc8d68eae2c42b8

C++ Support(0)　
https://qiita.com/kaizen_nagoya/items/8720d26f762369a80514

Coding(0) Rules, C, Secure, MISRA and so on
https://qiita.com/kaizen_nagoya/items/400725644a8a0e90fbb0

coding (101) 一覧を作成し始めた。omake:最近のQiitaで表示しない5つの事象
https://qiita.com/kaizen_nagoya/items/20667f09f19598aedb68

プログラマによる、プログラマのための、統計(0)と確率のプログラミングとその後
https://qiita.com/kaizen_nagoya/items/6e9897eb641268766909

なぜdockerで機械学習するか 書籍・ソース一覧作成中 (目標100)
https://qiita.com/kaizen_nagoya/items/ddd12477544bf5ba85e2

言語処理100本ノックをdockerで。python覚えるのに最適。:10+12
https://qiita.com/kaizen_nagoya/items/7e7eb7c543e0c18438c4

プログラムちょい替え（0）一覧:4件
https://qiita.com/kaizen_nagoya/items/296d87ef4bfd516bc394

Python(0)記事をまとめたい。
https://qiita.com/kaizen_nagoya/items/088c57d70ab6904ebb53

官公庁・学校・公的団体（NPOを含む）システムの課題、官（０）
https://qiita.com/kaizen_nagoya/items/04ee6eaf7ec13d3af4c3

「はじめての」シリーズ　 ベクタージャパン　
https://qiita.com/kaizen_nagoya/items/2e41634f6e21a3cf74eb

AUTOSAR(0)Qiita記事一覧, OSEK(75)
https://qiita.com/kaizen_nagoya/items/89c07961b59a8754c869

プログラマが知っていると良い「公序良俗」
https://qiita.com/kaizen_nagoya/items/9fe7c0dfac2fbd77a945

LaTeX(0) 一覧　
https://qiita.com/kaizen_nagoya/items/e3f7dafacab58c499792

自動制御、制御工学一覧（０）
https://qiita.com/kaizen_nagoya/items/7767a4e19a6ae1479e6b

Rust(0) 一覧　
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100以上いいねをいただいた記事16選
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小川清最終講義、最終講義（再）計画, Ethernet(100) 英語(100) 安全(100)
https://qiita.com/kaizen_nagoya/items/e2df642e3951e35e6a53

＜この記事は個人の過去の経験に基づく個人の感想です。現在所属する組織、業務とは関係がありません。＞
This article is an individual impression based on my individual experience. It has nothing to do with the organization or business to which I currently belong.
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