E-Mail: [e-mail]

1
?????? (11)
- ?????? (2)

• ????? Mobile IP, SIP Mobility
• ????? IEEE 802.11e (WiFi Multimedia)
• ????? CRTP, ROHC
• ?????? SIP Security, Secure RTP

?????????? ???? E-Mail katto_at_waseda.jp
2
?????

• L3????? Mobile IP
• L7????? SIP Mobility

3
Mobile IP (1)

• Mobile IPv4 (??????)

CN (Corresponding Node)
HA (Home Agent)
Registration (CoA)
??
FA (Foreign Agent)
MN (Mobile Node)

• ??????? (MN ???)
• ?????? (CoA ???)

Router Advertisement
4
Mobile IP (2)

• Mobile IPv4 (?????????)

IP????
CN (Corresponding Node)
HA (Home Agent)
MN
MN
???
CN
???
?????
??
MN
???
CoA
FA (Foreign Agent)
MN (Mobile Node)

• ??????? (MN ???)
• ?????? (CoA ???)

5
Mobile IP (3)

• Mobile IPv4 (?????)

• MN (Mobile Node) ????
• CoA (Care of Address) ?????? (?????????)
• HA (Home Agent) ?????????
• FA (Foreign Agent) ?????????
• CN (Corresponding Node) ????

??
???????????

• MN ? FA ?? CoA ???? (Discovery Advertisement,
  DHCP ?)?
• MN ? HA ? CoA ????? (Registration)?
• CN ???????? HA ? MN ?????????? (Delivery)?
• MN ?????????????????????????
• MN ?????????? MN ????CN ????????????

6
Mobile IP (4)

• Route Optimization (????????????)

CN (Corresponding Node)
HA (Home Agent)
Binding Update (CoA)
CN
???
Registration (CoA)
??
FA (Foreign Agent)
MN (Mobile Node)
CN ??????
7
Mobile IP (5)

• Fast Handover (1) ??

?? ?????????
CN

1. ???????????
2. ?????????

FA 2
FA 1
??
MN

1. ??? MIP (HMIP)
2. ???????
3. ?????????

??
8
Mobile IP (6)

• Fast Handover (2) ??? MIP

HA
CN
FA ????? ????????????????? ? MAP
?????????????? ????????
MAP
MAP Mobility Anchor Point AR Access Router
Regional Registration
AR1
AR2
AR3
AR4
??
MN
9
Mobile IP (7)

• Fast Handover (3) ?????????????????

Buffering (Fast MIP)
Bi-casting (Simultaneous Binding)
CN
CN
New FA
Old FA
New FA
Old FA
MN
MN
??
??
????????? HMIP ?????????? (CN ? MAP ??????)
10
Mobile IP (8)

• Mobile IPv6 (?????)

CN (Corresponding Node)
HA (Home Agent)
MN
???
Binding Update (CoA)
Registration (CoA)
??
IPv6 Router
FA (Foreign Agent)
MN (Mobile Node)
???????????? IPv6?????

• ??????? (MN ???)
• ?????? (CoA ???)

11
Mobile IP (9)

• Mobile IPv6 (?????)

IPv4 ????
FA ??? IPv6 Stateless Address Autoconfiguration H
ome Address Option MN ????????? CoA
????? Destination Option Binding Update
?????????????? ? Route Optimization ? (MIP??????)
IPv6 ???????
MIPv6 ???
MN ? CoA ????? (Stateless Address
Autoconfiguration)? MN ? HA ? CoA ????? (MIP
Registration)? CN ?????????HA ?????????? MN
???? MN ??Binding Update ?????CN ????????? ???MN
? CN ??HA ??????????????
12
SIP????? (1)

• ?????????? ??????

CN
SIP Location Server
? SIP Invite
? 302 Client Moved
? Registration (????)
? SIP Invite (CN?MN) ? 200 OK (MN?CN) ? VoIP or
streaming
??
? ??????
DHCP Server
MN
MIP Route Optimization ??????
13
SIP????? (2)

• ??????????? ??????

CN
SIP Location Server
? Re-registration (????)
? MN Moves (MN?CN) ? SIP Re-Invite (CN?MN) ? 200
SIP OK (MN?CN) ? VoIP or streaming
New AR
Old AR
? ??????
MN
??
SIP ????????? (??????????????)
14
SIP????? (3)

• ??????????

CN
SIP Location Server
? Invite / Client Moved
? VoIP or streaming
? Registration (????)
sipjiro_at_foo.com ? place3.foo.com
Place 1
Place 2
Place 3
??????????????????????
15
MIP Mobility vs. SIP Mobility
?????????
16
?????

• IEEE 802.11e (WiFi Multimedia)

17
IEEE 802.11

• ??LAN

18
IEEE 802.11 DCF

• DCF Distributed Coordinated Function

RTS/CTS/DATA/ACK
S
D
RTS RequestToSend CTS ClearToSend NAV Network
Allocation Vectors SIFS Short Inter-Frame
Space DIFS Distributed Inter-Frame Space
O
19
??LAN?QoS??

• Service Differentiation

IEEE 802.11e
20
IEEE 802.11 EDCF (1)

• EDCF Enhanced Distributed Coordinated Function

?????????????????????????
?????????
AC Access Categories AIFS Arbitration
Inter-Frame Space CW Contention Window
21
IEEE 802.11 EDCF (2)

• ???

WME WiFi Multimedia Extension
ITU-T Workshop on Home Networking and Home
Services, June 2004.
22
?????

• RFC 2508 Compressing IP/UDP/RTP Headers
• for Low Speed Serial Links
• RFC 3095 Robust Header Compression

23
(??) TCP/IP Header Compression
RFC 1144
2060
20
IP
TCP
???
3
???
compressed header
24
RFC 2508
IP/UDP/RTP Header Compression (CRTP)
20
12
8
IP
RTP
???
UDP
2
???
compressed header
(COMPRESSED_RTP)
25
CRTP??????
IP
UDP
RTP
FULL_HEADER
??? (?????)
COMPRESSED_RTP
?? (2???)
COMPRESSED_UDP
??
??? (?????)
CONTEXT_STATE
?????? (???????)
COMPRESSED_NON_TCP
RFC 2507 (IP Header Compression)
???
26
COMPRESSED_RTP
1 byte
CID Context ID ? FULL_HEADER ???
CID ? MSB
CID ? MSB
??
M
S
T
I
seq
UDP ??????
IP ?????
MSTI 1111 ??? (CSRC ?)
M
S
T
I
CC
??? ??
IPv4 ID ???
I or I 1
RTP ???????????
S or S 1
RTP ??????????
T or T 1
CSRC ???
40???
2???
27
RFC 3095
ROHC (Robust Header Compression)

• CRTP???

CRTP ?????????????????????????????? ?
????????????????????????? ? ??????????????????????
(??????) ??? ????????????????? CONTEXT_STATE
???? (??? ??????) ????????????
ROHC (Robust Header Compression) (1)
????????????????? ???? ???????????? ??????????????
?????? (2) ????????? (2.5G/3G ?) ?? VoIP
??????????? ????? LAN ?? VoIP (VoWLAN) ?????????
28
ROHC ????????

• IP/UDP/RTP ????????????????

INFERED ??????????????? (? ??????) STATIC
????????????? (? ???????) STATIC-DEF ??????
Static ????? (IP ??????????) STATIC-KNOWN ????
Static ????? CHANGING ??????? Dynamic ????? (?
?????????????????M????)
S.Rein et al Voice Quality Evaluation for
Wireless Transmission with ROHC, June 2003.
29
ROHC ????? (1)

• ????????

• ????????

??????????
IR Initialization Refresh (???) ?
?????????????? FO First Order (??) ? Dynamic
????????? SO Second Order (??) ? ???????????
NC No Context (???) ? ?????????? SC Static
Context (??) ? Dynamic ??????????? FC Full
Context (??) ? ?????????????????
30
ROHC ????? (2)

• ????????

• ?????????????

Unidirectional mode
???????????????????
Unidirectional mode ? ????????
???????? Optimistic mode ? ????????????????????
Reliable mode ? ????????????????????
Optimistic mode
Reliable mode
31
ROHC??????

• ?????????????????????

??????????????????????????????????? (?? ?)
??????????? (????????????????)??????? ????????????
???????????
Window based LSB encoding ???????????????????????
??????? (LSB encoding)? ??????????????????????????
??????????? ?????????????????????????? Self
describing variable length value ??????
0?10?110?111 ?????????????????????? (? ?
7?14?21?29 ???)???????????????????????
32
ROHC???????????

• ?????????????????????????????????

1 byte
CID ????????????ID base header
???????????????? ??????? dynamic
?????????? extended header ????????????? ??????
Add-CID
??
base header
extended header
RTP???
33
ROHC??????

• ???????

• ?????????

?? ??????? (BER) ?? ??????? (PER) ? ROHC ?
CRTP ?????????????
?? ?????????? ?? ?? ? ROHC ? CRTP ?????????????
L.E.Jonsson et al Header Compression for
IP-Telephony over Cellular Links, July 1999.
34
??????

• SIP Security (?????????)
• RFC 3711 Secure RTP (????????)

35
SIP Security (1)

• HTTP?? (Digest??) ?????

????
????
User A
User B
User A
User B
INVITE
INVITE
401 Unauthorized
200 OK
challenge
ACK
ACK
INVITE Authorization
????
200 OK
?????? ???? ??????
ACK
36
SIP Security (2)

• ?????? ?????

User A
Proxy
User B
INVITE
407 Proxy Authentification
ACK
Proxy ????
INVITE Proxy Authorization
INVITE
401 Unauthorized
401 Unauthorized
ACK
ACK
INVITE Proxy Authorization Authorization
User ????
????
User ????
INVITE Authorization
200 OK
200 OK
ACK
37
Secure RTP

• RTP/RTCP????????

SDP??????????
User A
User B
INVITE
SDP
200 OK
SDP
????
ACK
????
??????
38
??????
39
???
? ??????? (??)
? VoIP (??)
? ???????? (RTP, TFRC)
Internet
? TCP/IP
? ??????????
? ?? (CDN, P2P)
? ?????? ? DRM ? ???? ? ?????????
? ?????? (MPEG, H.26X)