NATのしくみと NAT越え技術 - 名城大学

1 NAT . NAT . 150441104 . 2 . NAT Network Address Translation( . ). (PC) IP . ( ) . IP .. Symmetric Cone . 3 IP .. IP .. IP .. IP . 4 . NAT Network Address Translation( . ). (PC) IP . ( ) . IP .. Symmetric Cone . 5 .. NAT IP . Symmetric Cone . Symmetric . Cone . 6 Symmetric ( ). PC IP .. = P1:k = G2:l IP . P1 P2 G1 Internet G2. NAT. PC.. 7 Symmetric ( ). NAT .. = G1:m = G2:l IP . P1 P2 G1 Internet G2. NAT. PC.. 8 Symmetric ( ). NAT . NAT . G2:l P1:k G1:m = G1:m = G2:l IP . P1 P2 G1 Internet G2. NAT. PC.. 9 Symmetric ( ). NAT . NAT . G2:l P1:k G1:m = G2: . = G1:m IP . P1 P2 G1 Internet G2. NAT. PC.. 10 Symmetric ( ). NAT . NAT . G2:l P1:k G1:m = G2: . = P1:k IP . P1 P2 G1 Internet G2. NAT. PC.. 11 Symmetric ( ). NAT . NAT . G2:l P1:k G1:m = G2: . = P1:k IP . P1 P2 G1 Internet G2. NAT. PC.. 12 Symmetric ( ). NAT . NAT . G2:l P1:k G1:m = G2:a = G1:m IP . P1 P2 G1 Internet G2. NAT. PC.. 13 Symmetric ( ). NAT . NAT . G2:l P1:k G1:m = G2:a = G1:m IP.

2 P1 P2 G1 Internet G2. NAT. PC.. 14 Cone ( ). PC IP .. = P1:k = G2:l IP . P1 P2 G1 Internet G2. NAT. PC.. 15 Cone ( ). NAT .. = G1:m = G2:l IP . P1 P2 G1 Internet G2. NAT. PC.. 16 Cone ( ). NAT . NAT . ( ) P1:k G1:m = G1:m = G2:l IP . P1 P2 G1 Internet G2. NAT. PC.. 17 Cone ( ). NAT . NAT . P1:k G1:m = G2:l = G1:m IP . P1 P2 G1 Internet G2. NAT. PC.. 18 Cone ( ). NAT . NAT . P1:k G1:m = G2:l = P1:k IP . P1 P2 G1 Internet G2. NAT. PC.. 19 Cone ( ). NAT . NAT . P1:k G1:m = G2:l = P1:k IP . P1 P2 G1 Internet G2. NAT. PC.. 20 Cone ( ). NAT . NAT . P1:k G1:m = G2:a = G1:m IP . P1 P2 G1 Internet G2. NAT. PC.. 21 Cone ( ). NAT . NAT . P1:k G1:m = G2:a = P1:k IP . P1 P2 G1 Internet G2. NAT. PC.. 22 Cone ( ). NAT . NAT . P1:k G1:m = G2:a = P1:k IP . P1 P2 G1 Internet G2. NAT. PC.. 23 Cone NAT . Full Cone NAT. WAN . IP .. Address-Restricted Cone NAT. IP . IP .. Port Restricted Cone NAT. IP . IP .. 24 Full Cone NAT. WAN . IP .. A. =. =.

3 G2:l = G2:X. G3:l =. = P1:k P1:k II PP .. G3. P1 P2 G1 Internet B. NAT NAT . G2. PC1. P1:k G1:m G2:l . 25 Address-Restricted Cone NAT. IP . IP .. A. = G2:X. = G2:l G3:l = P1:k IP . G3. P1 P2 G1 Internet B. NAT NAT . G2. PC1. P1:k G1:m 26 Port Restricted Cone NAT. IP . IP .. A. = G2:X. = G3:l G2:l = P1:k IP . G3. P1 P2 G1 Internet B. NAT NAT . G2. PC1. P1:k G1:m 27 NAT .. NAT NAT .. P2. = G1:l = G2:k IP P3. P1. G1. Internet G2. P4. 28 NAT . STUN(Simple traversal of UDP through NATs). TURN( traversal Using Relay NAT). ICE(Interactive Connectivity Establishment). 29 Cone NAT STUN ( ). PC1 IP . STUN (STUN Binding Request ). = P1:k = G3:s = PC1. IP . G3 STUN. P1 P2 G1 Internet . NAT. G2. PC1 .. 30 Cone NAT STUN ( ). NAT . STUN PC1 G1:m . = G1:m PC1 is [G1:m]. = G3:s = PC1. IP . G3 STUN. P1 P2 G1 Internet . NAT NAT . G2. PC1 . P1:k G1:m 31 Cone NAT STUN . STUN PC1 . PC1 is [G1:m]. Query PC1? G3 STUN. P1 P2 G1 Internet . NAT NAT . G2.

4 PC1 . P1:k G1:m 32 Cone NAT STUN . STUN PC1 . PC1 is [G1:m]. G3 STUN. P1 P2 G1 Internet . NAT. G2. PC1 PC1 is [G1:m].. 33 Cone NAT STUN . PC1 .. PC1 is [G1:m]. = G2:l = G1:m IP . G3 STUN. P1 P2 G1 Internet . NAT NAT . G2. PC1 . P1:k G1:m 34 Cone NAT STUN . Cone NAT . PC1 is [G1:m]. = G2:l = P1:k IP . G3 STUN. P1 P2 G1 Internet . NAT NAT . G2. PC1 . P1:k G1:m 35 Cone NAT STUN . Cone NAT . PC1 is [G1:m]. = G2:l = P1:k IP . G3 STUN. P1 P2 G1 Internet . NAT NAT . G2. PC1 . P1:k G1:m 36 TURN ( ).. TURN . (G2:n).. P1 G1 G2:l G2:n Internet P2. NAT. PC1 G2:n TURN .. 37 TURN ( ). TURN ( PC2 ).. Create Permission request (PC2). P1 G1 G2:l G2:n Internet P2. NAT. PC1 Create Permission response TURN .. 38 TURN ( ). TURN .. +.. PC1. TURN PC2. 39 ICE . STUN TURN .. 1.. 2.. 3.. 4.. 5.. 40 . Agent STUN NAT IP . TURN IP . ( Host Candidate, Server Reflexive Candidate, Relayed Candidate ). G3 STUN. A:a P2 B:b Internet . NAT. G2 C:c Agent TURN.

5 41 .. Priority = 224 + 28 . + 20 (256 ). Type preference: . HOST 126( ),SERVER REFLEXIVE 100, RELAYED 0 . Local preference:IP . NAT IP .. Component ID:1~256 . RTP 1 RTCP 2. 42 .. STUN.. NAT . A:a B:b NAT . A:a 43 . SDP(Session Description Protocol) .. IP IP. Port Protocol Type Port Protocol Type Address Address UDP HOST UDP HOST. UDP HOST UDP SERVER.. UDP RELAYED UDP RELAYED. Agent L Controlling Agent Agent R Controlled Agent . 44 . STUN Binding request/response .. STUN Binding response .. (success response) . IP Binding request . IP . IP Binding request . IP . 45 .. Regular Nomination . Flag STUN Binding request . Aggressive Nomination Flag STUN. Binding request .. 46 . NAT (PC) . IP ( ) .. Symmetric Cone . NAT . STUN. TURN. ICE. 47 . RFC 5245 Interactive Connectivity Establishment (ICE) : A Protocol for Network Address Translator (NAT) traversal for Offer/Answer Protocols . (2018/04/12). Symmetric NAT NAT . (2018/04/11). ICE Interactive Connectivity Establishment.

6 (2018/04/13). WebRTC ICE . (2018/04/11). NAT . (2018/04/11).