SHIP Performance Reference SHIP mobility management hybrid SIPHIP

SHIP: Performance Reference: “SHIP mobility management hybrid SIP-HIP scheme” 　　　　　　So, J. Y. H. ; Jidong Wang; Jones, D. ; 　　　　　　Sixth International Conference on 23 -25 May 2005 　　　　　　Page(s): 226 - 230 　　　　　　Digital Object ID 10. 1109/SNPD-SAWN. 2005. 68 2005/12/6

Background n n n In the current wireless networks, wireless management can be handled in Data Link Layer or Physical Layer In the 4 G wireless networks, handover between different wireless networks can’t be handle by the old method Network Layer and Application Layer are the most suitable layers for the mobility management 2005/12/6 2

Session Initiation Protocol n n n An Application Layer protocol used to create or tear down multimedia session Can perform mobility support that is independent of the underlying wireless technology and network layer element in the Application Layer The best choice for real-time application only 2005/12/6 3

Session Initiation Protocol (cont. ) n n Application Layer protocol will get lowest priority in networking model and so a long delay in hand-off will occur Doesn’t support mobility in other connections that aren’t created under SIP Hybrid SIP and other protocols are considered by many research changing addresses or ports, adding a media stream, deleting a media stream, etc. ¡ 2005/12/6 re-INVITE 4

Host Identify Protocol n n n Introduces a new namespace - Host Identity and a new layer - Host Identity Layer HI (Host Identifier) is represented with a 128 bit long HIT (Host Identity Tag) HI that is a cryptographic key of a publicprivate key-pair will be used to identify node and endpoint instead of IP addresses 0　　　　　　7 8　　　　　　 127 Prefix 2005/12/6 Hash 5

Host Identity Layer 2005/12/6 6

Host Identify Protocol (cont. ) n n n 4 -way handshake Diffie-Hellman authenticated key is exchanged during handshake Diffie-Hellman key is used to establish a pair of IPsec ESP (Encapsulated Security Payload) SAs (Security Associations) between hosts 2005/12/6 7

4 -way handshake of HIP Initiator Responder I 1: trigger exchange Select pre-computed R 1: puzzle, D-H, key, sig Check sig Solve puzzle Remain stateless I 2: solution, D-H, {key}, sig Compute D-H Check puzzle　Check sig R 2: sig Check sig Compute D-H Security Context established 2005/12/6 ESP protected messages 8

HIP packet structure n Packets traveling in the network doesn’t contain the actual HI information 0　　　　 7 8　　　　15 1617　　　　　　 2324　　 2728　 3031 Next Header Length 0 Packet Type Checksum VER. RES. 1 Controls Sender's Host Identity Tag Receiver's Host Identity Tag HIP Parameters 2005/12/6 9

HIP packet structure (cont. ) n Arriving packets is identified and mapped to the correct SA using the SPI (Security Parameter Index) value in the IPsec header 2005/12/6 10

HIP - mobility n n DNS may not be able to update immediately RVS (Rendezvous Server) is similar to the HA in Mobile IP DNS will carry the mapping between FQDN and the corresponding RVS IP addresses Direct mapping between HI and IP addresses of the host will be stored in RVS 2005/12/6 11

4 -way handshake of HIP via RVS 2005/12/6 12

HI-IP Mapping A. DNS only 2005/12/6 B. DNS with RVS 13

HIP - Mid-session mobility n n Send the UPDATE package with REA (Readdress) parameter to the other nodes and its RVS Critical scenarios ¡ ¡ ¡ 2005/12/6 Double jump problem IP address changes during the 4 -way handshakes Solved by involving RVS 14

SHIP (Hybrid SIP-HIP) n Pre-session ¡ ¡ n SIP location server will return the HI address instead of an IP address Until the mapping of the SIP, URI and HI address is changed, no updates are required in the SIP location server Mid-session ¡ ¡ 2005/12/6 HIP UPDATE package with REA parameter will be sent to the corresponding host SIP doesn’t need to send re-INVITE message 15

SHIP Procedures 2005/12/6 16

Handoff Signaling Analysis n Dhandoff = Ddhcp + Dnotice = n Ohandoff = n 2005/12/6 17

Handoff Signaling Parameters Symbol Meaning Typical value Ddhcp Delay of DHCP address assignment 1 s Dnotice Delay for MH to notify CH of its new location BWwired Bandwidth of wired links 100 Mb/s BWwireless Bandwidth of wireless links 11 Mb/s (802. 11 b) Lwired Latency of wired links 0. 5 ms Lwireless Latency of wireless links 2 ms H Distance between MH and CH in hops L IP packet length of notice message Ts Average time for which MH remains in a subnet 2005/12/6 18

Handoff Signaling Delay 2005/12/6 SIP =140 bytes; HIP = 80 bytes; Mobile IP = 56 bytes 19

Handoff Signaling Delay (cont. ) n Hybrid SIP-Mobile IP need to use HA to redirect the packet until the SIP re-INVITE progress is completed ¡ n Two handoff processes are needed in one handoff Handoff only needs to be processed once in SHIP 2005/12/6 20

Handoff Signaling Overhead 2005/12/6 H=50 21

Handoff Signaling Overhead (cont. ) n n Overhead of hybrid SIP-Mobile IP scheme will be the sum of the Mobile IP and SIP as two handoff processes are needed SHIP has been shown to outperform than hybrid SIP-Mobile IP 2005/12/6 22

Conclusion n This paper has proposed SHIP for future IP based wireless networks SHIP avoids the re-INVITE message in SIP and therefore, its signaling message is smaller SHIP also provides multi-homing support, which does not exist in hybrid SIP-Mobile IP 2005/12/6 23

Reference n n Session Initiation Protocol ¡ RFC-3261 HIP Working Group (Internet-Draft) ¡ n Host Identity Protocol - Extended Abstract ¡ n http: //www. ietf. org/html. charters/hip-charter. html Ericsson Research, Nomadic. Lab (WWRF 8 bis) Mobility support in wireless Internet ¡ 2005/12/6 Wireless Communications (IEEE) 24