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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. Background .
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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
Background • In the current wireless networks, wireless management can be handled in Data Link Layer or Physical Layer • In the 4G 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
Session Initiation Protocol • 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
Session Initiation Protocol (cont.) • 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. • re-INVITE
Host Identify Protocol • 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 public-private key-pair will be used to identify node and endpoint instead of IP addresses
Host Identify Protocol (cont.) • 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
4-way handshake of HIP Initiator Responder I1: trigger exchange Select pre-computed R1 R1: puzzle, D-H, key, sig Check sig Remain stateless Solve puzzle I2: solution, D-H, {key}, sig Compute D-H Check puzzleCheck sig R2: sig Check sig Compute D-H Security Context established ESP protected messages
HIP packet structure • Packets traveling in the network doesn’t contain the actual HI information
HIP packet structure (cont.) • Arriving packets is identified and mapped to the correct SA using the SPI (Security Parameter Index) value in the IPsec header
HIP - mobility • 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
HI-IP Mapping A.DNS only B.DNS with RVS
HIP - Mid-session mobility • Send the UPDATE package with REA (Readdress) parameter to the other nodes and its RVS • Critical scenarios • Double jump problem • IP address changes during the 4-way handshakes • Solved by involving RVS
SHIP (Hybrid SIP-HIP) • Pre-session • 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 • HIP UPDATE package with REA parameter will be sent to the corresponding host • SIP doesn’t need to send re-INVITE message
Dhandoff = Ddhcp + Dnotice Dnotice = Ohandoff = Handoff Signaling Analysis
Handoff Signaling Delay SIP =140 bytes; HIP = 80 bytes; Mobile IP = 56 bytes
Handoff Signaling Delay (cont.) • Hybrid SIP-Mobile IP need to use HA to re-direct the packet until the SIP re-INVITE progress is completed • Two handoff processes are needed in one handoff • Handoff only needs to be processed once in SHIP
Handoff Signaling Overhead (cont.) • 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
Conclusion • 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
Reference • Session Initiation Protocol • RFC-3261 • HIP Working Group (Internet-Draft) • http://www.ietf.org/html.charters/hip-charter.html • Host Identity Protocol - Extended Abstract • Ericsson Research, NomadicLab (WWRF8bis) • Mobility support in wireless Internet • Wireless Communications (IEEE)