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SIP IPv6/IPv4 transition solutions
通訊所 鍾國麟
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Outline
• IPV6 transition problem
• NAT-PT + SIP ALG
• TZI gateway
• 3GPP – IMS
• STUN-Based SIP Proxy
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IPV6 / IPV4 SIP 發生的問題
NAT-PT
IPv4 IPv6
IPv4 SIP_UA
IPv6 SIP_UAINVITE [email protected] IPv4 SDPA=140.123.1.1 … 看不懂 IPv4 位址
?? 140.123.1.1IP Mapping table
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NAT-PT + SIP ALG
DUAL-StackTranslator
IPv4 IPv6
SIP ALG
Media session Translator
IPv4 SIP UAIPv6 SIP UA
140.123.1.1 FF::1
INVITE [email protected] IPv4 SDPA=140.123.1.1 …
INVITE [email protected] IPv4 SDPA=FE::AA:1:1
IP Mapping tableRTP (ipv4) RTP (ipv6)
SIP_ALG Modify SIP/SDP Message
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TZI Gateway•
6WINIT Project; http://www.6winit.org• The TZI-Gateway is a application layer gatew
ay for signalling communication and media streams for use in heterogeneous IPv4/IPv6 networks
• Determine IP version of caller based on received INVITE message
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TZI Gateway 6WINIT Project; http://www.6winit.org
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3GPP-IMS Scenario
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3GPP-IMS Scenario– 3GPP IPv6 endpoint
• IPv6-only but IPv4-aware
– SIP Edge Proxy• Logical proxy entity• Dual-Stack• Manages pools of IPv6 and IPv4 addresses for one or multiple IPAP
Ms
– IP Address and Port Mapper (IPAPM)• IP translation (comparable to SIIT)• Manages address/port bindings• Controlled by edge proxy
– Control protocol• To be defined
– MEGACO, MIDCOM…
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• 目前 IPv6/IPv4 SIP solution– 需修改 NAT-PT , Gateway– SIP Proxy 和需 NAT-PT 合作 (IP Mapping)
• 利用 STUN 方法在 IPV6/IPV4 環境中穿透 NAT-PT 使得 SIP 可以通話。
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STUN - Simple Traversal of UDP Through NATs
NAT
Internet (Public Network)Private Network
192.168.1.1STUN server
IP mapping table
S: 192.168.1.1
Packet
140.123.1.xx
S:140.123.1.1
D:140.123.1.1 IP :140.123.1.1原來我對外的 IP 是 140.123.1.1
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STUN-based SIP Proxy
NAT-PT
IPv4 IPv6
IPv4 SIP_UA
IPv6 SIP_UAIP Mapping table
SIP ProxySIP Proxy
Dual stackRTP Relay
Dual stackRTP Relay
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• STUN-based SIP Proxy– Dual stack– Change SDP– RTP Relay– STUN
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IPV4 - SIPUA SIP Proxy 01 NAT-PT SIP Proxy 02 IPV6 - SIPUA
INVITE
STUN request
STUN response
INVITE
INVITE
OKSTUN request
STUN response
OKOK
RTP RTP RTP RTPRelay Relay
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IPV4 - SIPUA SIP Proxy 01 NAT-PT SIP Proxy 02 IPV6 - SIPUA
INVITE
INVITE [email protected]
SDP: 140.123.1.1
140.123.1.1 140.123.1.2FF::2 FF::1
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IPV4 - SIPUA SIP Proxy 01 NAT-PT SIP Proxy 02 IPV6 - SIPUA
INVITE
140.123.1.1 140.123.1.2FF::2 FF::1
S:140.123.1.2
IP: AA::1
STUN request
STUN response S:140.123.1.2
S: AA::1
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IPV4 - SIPUA SIP Proxy 01 NAT-PT SIP Proxy 02 IPV6 - SIPUA
INVITE
140.123.1.1 140.123.1.2FF::2 FF::1
S:140.123.1.2
IP: AA::1
STUN request
STUN response
INVITE
INVITE [email protected]
SDP: AA::1
INVITE
INVITE [email protected]: FF::2
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IPV4 - SIPUA SIP Proxy 01 NAT-PT SIP Proxy 02 IPV6 - SIPUA
INVITE
140.123.1.1 140.123.1.2FF::2 FF::1
S:140.123.1.2
IP: AA::1
STUN request
STUN response
INVITEINVITE [email protected]: AA::1
INVITE
INVITE [email protected]: FF::2
OK
200 OKSDP: FF::1
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IPV4 - SIPUA SIP Proxy 01 NAT-PT SIP Proxy 02 IPV6 - SIPUA
INVITE
140.123.1.1 140.123.1.2FF::2 FF::1
S:140.123.1.2
IP: AA::1
STUN request
STUN response
INVITEINVITE [email protected]: AA::1
INVITE
INVITE [email protected]: FF::2
OK200 OKSDP: FF::1
STUN request
STUN response
S:FF::2
IP: 163.1.1.1
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IPV4 - SIPUA SIP Proxy 01 NAT-PT SIP Proxy 02 IPV6 - SIPUA
INVITE
140.123.1.1 140.123.1.2FF::2 FF::1
S:140.123.1.2
IP: AA::1
STUN request
STUN response
INVITEINVITE [email protected]: AA::1
INVITE
INVITE [email protected]: FF::2
OK200 OKSDP: FF::1
STUN request
STUN response
S:FF::2
IP: 163.1.1.1
OKOK
200 OKSDP: 163.1.1.1
200 OKSDP: 140.123.1.2
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IPV4 - SIPUA SIP Proxy 01 NAT-PT SIP Proxy 02 IPV6 - SIPUA
INVITE
140.123.1.1 140.123.1.2FF::2 FF::1
S:140.123.1.2
IP: AA::1
STUN request
STUN response
INVITEINVITE [email protected]: AA::1
INVITE
INVITE [email protected]: FF::2
OK200 OKSDP: FF::1
STUN request
STUN response
S:FF::2
IP: 163.1.1.1
OKOK
200 OKSDP: 163.1.1.1
200 OKSDP: 140.123.1.2
ACK
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IPV4 - SIPUA SIP Proxy 01 NAT-PT SIP Proxy 02 IPV6 - SIPUA
INVITE
140.123.1.1 140.123.1.2FF::2 FF::1
S:140.123.1.2
IP: AA::1
STUN request
STUN response
INVITEINVITE [email protected]: AA::1
INVITE
INVITE [email protected]: FF::2
OK200 OKSDP: FF::1
STUN request
STUN response
S:FF::2
IP: 163.1.1.1
OKOK
200 OKSDP: 163.1.1.1
200 OKSDP: 140.123.1.2
ACK
RTP RTP RTP RTPRelay Relay
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結論• Modify Gateway
– NAT-PT+SIP ALG– TZI Gateway– 3G IMS
• 提出一個實驗性的架構在不修改 NAT-PT下,利用 SIP Proxy + STUN 使得 SIP 在 IPV6/IPV4 環境可使用
• NAT-PT 環境不容易架設