This slides explain the overview of the UDP Usage Guidelines described by draft-ietf-tsvwg-rfc5405bis-13, an IETF draft.

1. 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

2. Agenda
1. 本ドラフトのscope
2. RFC 5405からの主な修正点
3. Guidelines #1 – #24
2016/6/22 2

3. 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

4. Agenda
1. 本ドラフトのscope
2. RFC 5405からの主な修正点
3. Guidelines #1 – #24
2016/6/22 4

5. 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
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6. Agenda
1. 本ドラフトのscope
2. RFC 5405からの主な修正点
3. Guidelines #1 – #24
2016/6/22 6

7. 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. 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. 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. 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

11. 11
1. SHOULD provide mechanisms to regulate the bursts of
transmission
Guideline #5
バースト送信への対応

12. 12
1. MAY implement ECN; a specific set of application
mechanisms are REQUIRED if ECN is used
Guideline #6
ECNの利用

13. 13
1. For DiffServ, SHOULD NOT rely on implementation of PHBs
Guideline #7
DiffServ対応

14. 14
1. For QoS‐enabled paths, MAY choose not to use CC
Guideline #8
RSVP対応

15. 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. 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

17. 17
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. 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

19. 19
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. 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

21. 21
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

22. 22
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. 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

24. 24
1. Bulk multicast apps SHOULD implement congestion control
Guideline #18
バルク通信を実施するマルチキャスト対応

25. 25
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

26. 26
1. Multicast apps SHOULD use a safe PMTU
Guideline #20
マルチキャスト通信でのパケットサイズ

27. 27
1. SHOULD avoid using multiple ports
2. MUST check received IP source address
Guideline #21
複数ポート利用

28. 28
1. SHOULD validate payload in ICMP messages
Guideline #22
ICMPメッセージ対応

29. 29
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

30. 30
1. SHOULD use standard IETF security protocols when needed
Guideline #24
IETFセキュリティプロトコルの活用

31. 31
See “UDP Usage Guidelines” at
https://datatracker.ietf.org/doc/draft‐ietf‐tsvwg‐rfc5405bis/
Further details?