Overview of UDP Usage Guidelines [ISOC-JP event, 2016/6/22]
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Transcript of Overview of UDP Usage Guidelines [ISOC-JP event, 2016/6/22]
draft-ietf-tsvwg-rfc5405bis-13の概要“UDP Usage Guidelines”
高橋健志
情報通信研究機構
2016/6/22 1
ISOC-JP IETF Internet Draft読み込みWorkshop
本DraftのScope
• UDPの使い方に関するガイドライン
• Primary focusはcongestion control mechanism
• その他にも、メッセージサイズなどのトピックについても触れる
3
RFC5045からの主な変更点
• RFC5045はunicastにのみスコープを限定
• 本bisでは、IP anycast, multicast, broadcastも扱い、さらには、IPフローをサポートするUDPトンネルを利用するアプリについても触れている
5
7
1. MUST tolerate a wide range of Internet path conditions
2. SHOULD use a full‐featured transport (TCP, SCTP, DCCP)
Guideline #1
基本的な考え方
8
1. SHOULD control rate of transmission
2. SHOULD perform congestion control over all traffic
Guideline #2
輻輳制御の重要性
9
For bulk transfers,
1. SHOULD consider implementing TFRC
2. Else, SHOULD in other ways use bandwidth similar to TCP
Guideline #3
バルクデータ転送時の工夫
10
For non‐bulk transfers,
1. SHOULD measure RTT and transmit max. 1 datagram/RTT
2. Else, SHOULD send at most 1 datagram every 3 seconds
3. SHOULD back‐off retransmission timers following loss
Guideline #4
非バルクデータ転送時の工夫
12
1. MAY implement ECN; a specific set of application mechanisms are REQUIRED if ECN is used
Guideline #6
ECNの利用
15
1. SHOULD NOT rely solely on QoS for their capacity
2. Non‐CC controlled flows SHOULD implement a transport circuit breaker
3. MAY implement a circuit breaker for other applications
Guideline #9
サーキットブレーカーの重要性
16
For tunnels carrying IP traffic
1. SHOULD NOT perform congestion control
2. MUST correctly process the IP ECN field
Guideline #10
IPトンネリング対応
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For non‐IP tunnels or rate not determined by traffic,
1. SHOULD perform CC or use circuit breaker
2. SHOULD restrict types of traffic transport by the tunnel
Guideline #11
非IPトンネリング対応
18
1. SHOULD NOT send datagrams that exceed the PMTU, i.e., SHOULD discover PMTU or send datagrams < minimum PMTU;
2. Specific application mechanisms are REQUIRED if PLPMTUD is used
Guideline #12
パケットサイズの工夫
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1. SHOULD handle datagram loss, duplication, reordering
2. SHOULD be robust to delivery delays up to 2 minutes
Guideline #13
データの信頼性関連
20
1. SHOULD enable IPv4 UDP checksum
2. SHOULD enable IPv6 UDP checksum; Specific application mechanisms are REQUIRED if a zero IPv6 UDP checksum is used
Guideline #14
Checksum対応
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1. SHOULD provide protection from off‐path attacks
2. Else, MAY use UDP‐Lite with suitable checksum coverage
Guideline #15
Off‐path attack対応
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1. SHOULD NOT always send middlebox keep‐alive messages
2. MAY use keep‐alives when needed (min. interval 15 sec)
Guideline #16
Middleboxへのkeep‐alive message
23
1. Applications specified for use in limited use (or controlled environments) SHOULD identify equivalent mechanisms and describe their use‐case.
Guideline #17
Controlledな環境用のアプリ
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1. Low volume multicast apps SHOULD implement congestion control
Guideline #19
非バルク通信を実施するマルチキャスト対応
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1. SHOULD avoid using multiple ports
2. MUST check received IP source address
Guideline #21
複数ポート利用
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1. SHOULD use a randomized source port or equivalent technique, and, for client/server applications, SHOULD send responses from source address matching request
Guideline #23
ポート番号