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Supporting Mobile Wireless Internet Roaming Users in a SIP Environment. S. Baba & , J.-C. Chen + , A. Dutta + , N. Nakajima & , H. Schulzrinne * , Y. Shobatake & , and F. Vakil + + Telcordia Technologies & Toshiba America Research Inc. * Columbia University. - PowerPoint PPT Presentation
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Supporting Mobile Wireless Internet Roaming Users in a SIP Environment
An SAIC Company
S. Baba&, J.-C. Chen+, A. Dutta+, N. Nakajima&, H. Schulzrinne*, Y. Shobatake&, and F. Vakil+
+Telcordia Technologies&Toshiba America Research Inc.
*Columbia University
ITSUMOTM : Internet Technology Supporting Universal Mobile Operation
hmmp.ppt– 2Telcordia Technologies Proprietary - Internal use only. See proprietary restrictions on title page.
Outline
Motivation Objective Background End-to-end Architecture HMMP (Host Mobility Management Protocol)
– Built upon SIP signaling scheme Related Work Open Issues & Future work Demo Clip (If time permits) Discussion
hmmp.ppt– 3Telcordia Technologies Proprietary - Internal use only. See proprietary restrictions on title page.
Motivation
Mobility is rapidly becoming the rule rather than exception. SIP is gaining acceptance as the signaling protocol for
multimedia conferences and Internet telephony.
It is essential to support mobile users in a SIP signaling and control environment.
Current Wireless Efforts– 3GPP– 3G-IP– MWIF– 3GPP2
hmmp.ppt– 4Telcordia Technologies Proprietary - Internal use only. See proprietary restrictions on title page.
Objectives
Present a framework, i.e., host mobility management protocol (HMMP), for supporting roaming users in a mobile wireless Internet whose signaling system is built upon SIP.
Identify possible impacts of mobility on SIP and/or other protocols.
Propose “necessary extensions” for supporting mobility with SIP.
hmmp.ppt– 5Telcordia Technologies Proprietary - Internal use only. See proprietary restrictions on title page.
Framework RequirementsSIP based mobility management scheme for wireless IPnetworks would support personal as well as terminal mobility support global roaming support functions such as
– hand-off – registration– configuration– address binding– location management
be independent of underlying wireless technology support real-time and non-real time multimedia applications (i.e.,
both TCP and RTP/UDP based application) inter-work with today’s 1G/2G telephony smoothly
hmmp.ppt– 6Telcordia Technologies Proprietary - Internal use only. See proprietary restrictions on title page.
Service Profile for all IP wireless network user
ServicesRequirements
Multimedia Voice Data
Delay Stringent Stringent TolerantLoss/error Tolerant - Stringent Tolerant StringentBit rate (outdoor) Pedestrian 384 kb/s
Vehicular 144 kb/s
64 kb/s Pedestrian 384 kb/sVehicular 144 kb/s
Bit rate (indoor) 2 Mb/s 64kb/s 2Mb/sExampleapplications
Video streaming, videoconferencing
Mobile telephony File Transfer (e.g., ftp)to mobile
hmmp.ppt– 7Telcordia Technologies Proprietary - Internal use only. See proprietary restrictions on title page.
The Network Architecture
MS: Mobile Station
BS: Base Station
ERC: Edge Router & Controller
Control messages (i.e., signaling)
Domain Control Agent
Visited Network
Domain Control Agent
Wireline IP backbone network
Home Network
ERC
Internet
Regional IP network Regional IP
network
ERC
Inter-Domain Control Agent
Radio Access Network(RAN)
Radio Access Network(RAN)
BS
BSBS
BS
DCADCA
IDCA
MS
IP
hmmp.ppt– 8Telcordia Technologies Proprietary - Internal use only. See proprietary restrictions on title page.
Network Signaling and Control Architecture
Signaling:
Wireline IP backbone network
Internet
Visiting Registrar
3GAccess
SIP
3GAccess
SIP Server
MAAAQ SIP
VR
Regional IP network
Visiting Network
MS
DCA
Home Network
3GAccess
SIP
3GAccess
Regional IP network
SIP Server
MAAAQSIP
HR
Home Registrar
DCA
Inter-Domain Registrar
SIP Server
MAAAQ
IDR
IDCA
SIP UA in mobiles and hosts.
hmmp.ppt– 9Telcordia Technologies Proprietary - Internal use only. See proprietary restrictions on title page.
Network Elements
Mobile Station (MS)– User terminal– Adaptive software radios, i.e., full flexibility in the frequency
band– Control and management entity
Radio Access Network (RAN)– Provides MSs with access to the wireline infrastructure.– Set of base stations (BSs) and base station controllers
(BSCs)– Adaptive software radios– May support IP routing and control functions at BSs
Open Issue under study.
hmmp.ppt– 10Telcordia Technologies Proprietary - Internal use only. See proprietary restrictions on title page.
Network Elements (contd.)
Edge Router & Controller (ERC)– Comprises two elements
Edge Router (ER) with one or more interfaces to provide multiple subnets
Edge Control Agent (ECA): Control and management entity
– Default router of all MSs behind it Domain Control Agent (DCA)
– connection/session management – means of interaction (i.e., signaling)
between users and network control system, and among network control entities
– MAAAQ, i.e., Mobility management, Authentication, Authorization, and Accounting (AAA), and QoS management
hmmp.ppt– 11Telcordia Technologies Proprietary - Internal use only. See proprietary restrictions on title page.
What is HMMP? A protocol (framework) for supporting real-time and non-real-
time multimedia applications on mobile terminals of all IP networks.
Is built on top of existing personal mobility feature of Session Initiation Protocol (SIP).
Supports– domain hand-off (i.e., roaming) and– subnet hand-off (i.e., macro mobility), and– cell hand-off (i.e., micro mobility).
If base stations are not IP based, cell hand-off details are technology dependent.
Supports both real-time and non-real-time application Spoofs constant endpoints for TCP applications of roaming users
and supports TCP as is.
hmmp.ppt– 12Telcordia Technologies Proprietary - Internal use only. See proprietary restrictions on title page.
HMMP Overview: Cell hand-off (A --> B)
SIP Server
MAAAQ
SIP
HR
SIP
SIP Server
MAAAQ
VR
InternetRegional IP
networkRegional IP
network
Visiting Network Home Network
BSC 1 BS
BS
ERC 1
BSC 2
BS
ERC 2
ERC 3
BS
BS BSC 3
A
C
B D
Home RegistrarVisiting Registrar
Corresponding HostSIP
207.3.232.10
207.3.232.10
207.3.240.10128.59.10.6
IPch
hmmp.ppt– 13Telcordia Technologies Proprietary - Internal use only. See proprietary restrictions on title page.
Cell hand-off (Micro Mobility)
Mobile moves from A to B, BSC 1– Bind the mobile’s MAC address (or CDMA sequence) to port
B– Update the label translation table in BSC 1.– Technology dependent and is done via the link layer control
channels– SIP signaling may be involved to emulate soft hand-off
hmmp.ppt– 14Telcordia Technologies Proprietary - Internal use only. See proprietary restrictions on title page.
HMMP Overview: Subnet hand-off (B --> C)
SIP Server
MAAAQ
HR
INFO
SIP Server
MAAAQ
VR
Internet
Visiting Network Home Network
BSC 1 BS
BS
ERC 1
BSC 2
BS
ERC 2
ERC 3
BS
BS BSC 3
A
C
B D
Home RegistrarVisiting Registrar
Corresponding Host
DHCPDHCP
INVITE
• INFO method for address binding.
• DHCP updates the DNS.
IPch
207.3.232.10
207.3.232.10
207.3.240.10128.59.10.6
hmmp.ppt– 15Telcordia Technologies Proprietary - Internal use only. See proprietary restrictions on title page.
Subnet hand-off (Macro Mobility - Intra-Domain mobility)
Mobile moves further from B to C, and it is still registered with the network– The mobile asks a new temporary address from DHCP.
either directly or via a SIP registrar The DHCP gives the mobile a temporary IP address, the address of
its default gateway, and the subnet mask, nearest outbound SIP proxy server if needed
– The DHCP updates the domain name system (DNS) simultaneously for the new inbound connections
– mostly for mobile ftp/web applications
In public networks, the network may authenticate the mobile as a protection against fraud (Not a requirement).
The mobile or SIP server re-invites the corresponding host to the temporary address with new SDP parameters
hmmp.ppt– 16Telcordia Technologies Proprietary - Internal use only. See proprietary restrictions on title page.
Subnet hand-off (Contd.)– SIP server and network resource reservation scheme should create
a new route with adequate resources between the corresponding host and the mobile. This new route with adequate resources is only created for real-time
applications like voice. The non-real-time applications are allowed to traverse the network hop-
by-hop.
The mobile or SIP server creates a short-lived tunnel between ERC-1 and ERC-2 to reduce loss of the transient data due to hand-off.– Typically needed during hard hand-off– the mobile or SIP server informs ERC-1 to bind the previous address
of the mobile to its current one for a time-out period.This requires SIP user agents at all ERCs, and the address of the most recent ERC which is the most recent default
gateway.
– Tunnel creation is faster when both the interfaces are part of the same ERC.
hmmp.ppt– 17Telcordia Technologies Proprietary - Internal use only. See proprietary restrictions on title page.
HMMP Overview: Domain Hand-off ( C --> D)
SIP Server
MAAAQ
SIP
HR
SIP Server
MAAAQ
VR
Internet
Visiting Network Home Network
BSC 1 BS
BS
ERC 1
BSC 2
BS
ERC 2
ERC 3
BS
BS BSC 3
A
C
B D
Home RegistrarVisiting Registrar
Corresponding HostSIP
DHCPDHCP
INFO
INVITE
• Similar to Subnet hand-off plus AAA.
128.59.10.6
IPch
207.3.232.10
207.3.232.10207.3.240.10
SLA/SA
hmmp.ppt– 18Telcordia Technologies Proprietary - Internal use only. See proprietary restrictions on title page.
Domain Hand-off (Roaming)
Mobile moves further to D– The mobile requests for a temporary address and receives
one from DHCP. The DHCP updates the DNS simultaneously. – The mobile re-registers with its temporary address in the
new domain using the SIP REGISTER method. The mobile profile is added to the visiting registrar (VR), i.e.,
– its profile is replicated either through interaction of the VR with the HR or
– by pre-planned profile replications in the neighboring VRs.
– The mobile or SIP server re-invites the corresponding host with the new temporary address
– SIP server and network resource reservation scheme should create a new route with adequate resources between the corresponding host and the mobile.
hmmp.ppt– 19Telcordia Technologies Proprietary - Internal use only. See proprietary restrictions on title page.
Domain Hand-off (Roaming), …, Continued
HMMP ensures that the transient data is forwarded to the new address– The mobile or SIP server informs ERC-2 to bind the previous
address of the mobile to its current one for a time-out period. This requires SIP user agents at all ERCs, and the address of the most recent ERC which is the most recent
default gateway.
hmmp.ppt– 20Telcordia Technologies Proprietary - Internal use only. See proprietary restrictions on title page.
A typical Protocol Map for Inter-Domain mobility
DHCP DHCP
Domain1 Domain2
MT
MT
LocalSIPServer
PublicAAADatabase
LocalSIPServer
Network registration/ configuration
ServiceProfile
LocationDatabase
LAAADatabase
LAAADatabase
UserProfile
UserProfile
UserProfile
PublicSIPServer
1
3
55”
LocationDatabase
ServiceProfile
6’6
9
0
2
11LocationDatabaseService
Profile
10
DHCP+client
SIP client
SIP clientDHCP+
client
Service RegistrationLocation Update
Mobile moves
QoSQoS
SLA
2’
7
8
Home Visitor
hmmp.ppt– 21Telcordia Technologies Proprietary - Internal use only. See proprietary restrictions on title page.
Supporting TCP Applications with HMMP
SIP Server
MAAAQ
SIP
HR
SIP Server
MAAAQ
VR
Internet
Visiting Network Home Network
BSC 1 BS
BS
ERC 1
BSC 2
BS
ERC 2
ERC 3
BS
BSC 3
A
C
B D
Home RegistrarVisiting Registrar
Corresponding HostSIP
DHCPDHCP
SIP_EYE
Ongoing TCPConnections
INFO
INFO
INFO
• Equip MS with SIP_EYE.
IPch
207.3.232.10
207.3.232.10
207.3.240.10
128.59.10.6
IPch1
hmmp.ppt– 22Telcordia Technologies Proprietary - Internal use only. See proprietary restrictions on title page.
Supporting TCP Applications with HMMP A TCP connection is identified by a pair of endpoints, and each
endpoint is identified by a pair of integers (host, port).– host is IP address of the endpoint, and port is the TCP port on the host.
TCP applications– ftp, telnet, irc, web
The underlying idea of HMMP support of TCP are– SIP-Eye keeps track of ongoing TCP end-points– The MS informs the corresponding TCP endpoints about its new
address,– The corresponding host(s) bind (binds) the initial IP address of the MS
with its temporary one, and – The CH uses encapsulation to send TCP packets bearing the initial
source and destination addresses to the current location/address of the MS.
– MS does the encapsulation of its previous IP address with the new one and sends to CH
hmmp.ppt– 23Telcordia Technologies Proprietary - Internal use only. See proprietary restrictions on title page.
State of the Art: Related Work
CellularIP
Uses Mobile IP for global mobility. For macro-mobility it uses rules similar to HAWAII as far
as border router is concerned. It uses two parallel cache system , routing and paging, for
location update. Handoff is initiated by the mobile host
Hawaii
Proposes a 2-layer method for binding protocol. UsesMobile IP for global mobility.
For macro-mobility it assigns the mobile node an addressassociated with border router.
When moving within the foreign domain, MH retains itscare-of-address.
Base stations are capable of decapsulating packets andforwarding it to the mobile host.
Base station also determines whether to redirect theregistration to special routers in the domain or to the HA.
hmmp.ppt– 24Telcordia Technologies Proprietary - Internal use only. See proprietary restrictions on title page.
Related Work: Related Work
Mobile IP
Simple and scalable global mobility solution Needs support for fast handoff control, real-time location
tracking, authentication and distributed policymanagement
trust model to share a SA between 3 mobility entities Its triangular routing may adversely affect performance of
real-time services. Registration and configuration are tied with the mobility
architecture. There are different proposals for using mobile IP in a SIP
environment.- SIP based mobility for real-time services and mobile
IP for TCP applications (Wedlund, Schulzrinne).- SIP for location service and Mobile IP for address
binding (Calhoun, Kempf).
hmmp.ppt– 25Telcordia Technologies Proprietary - Internal use only. See proprietary restrictions on title page.
Why HMMP?Pros & Cons
Pros
No triangular routing of information, i.e., lower delay. Supports real-time and non-real-time applications.
- Needs a faster dynamic host configuration protocol. Minimizes the loss of transient data using short-lived
tunnels.- Its complexity – performance trade off require further study.
In principle, it requires no state in the network, tough isflexible enough to allow the network operator todetermine whether to maintain any state in the network.
Supports TCP as is.
Cons
Requires modification of the IP stack at hosts, MSs, androuters for encapsulation.
All hosts, MSs, and routers shall have SIP UA. It requires SIP_EYE agents in hosts and MSs.
- SIP-EYE agent can be implemented as part of the SIP-UA oras a separate entity that interacts with SIP-UA.
hmmp.ppt– 26Telcordia Technologies Proprietary - Internal use only. See proprietary restrictions on title page.
Possible Impact on other Protocols
It is desirable that – the SIP INFO method provides the means of profile verification
and/or replication, and address binding, – SIP registrar interacts with the AAA entity for inter-domain case– the SIP user agent is either equipped with a SIP_EYE agent or
interact with a SIP_EYE agent that maintains a record of ongoing TCP connections of the mobile, and
– the SIP user agent understands address binding INFO messages and takes necessary actions,
– Needs a faster configuration protocol (e.g., DRCP)
Either – the DHCP interacts with the DNS and updates it dynamically, or – a new protocol is developed to allow applications to use SIP
registrar for name to address and address to name mappings.
hmmp.ppt– 27Telcordia Technologies Proprietary - Internal use only. See proprietary restrictions on title page.
Open Issues & Future Work Proper use of the soft hand-off mechanism of the CDMA
technologies. Performance - complexity trade-off of the short-lived
tunneling between current and previous ERCs.– Other possible alternatives being looked into (e.g., SIP<->
multicast agent) Detailed specifications of the SIP_EYE agent and its relation
with the SIP UA.– Compare with other means of encapsulation method (e.g.,
closer to the base station) Interaction of the SIP Registrar with the AAA, if necessary.
– If a variant of DHCP (e.g., DRCP) is used, no interaction between AAA and Registrar is necessary.
Comparison with solutions that combines SIP & Mobile IP. A prototype of HMMP is being implemented now.
hmmp.ppt– 28Telcordia Technologies Proprietary - Internal use only. See proprietary restrictions on title page.
References M. Handley, H. Schulzrinne, E. Schooler, J. Rosenberg, “SIP: Session Initiation Protocol, RFC 2543 (Proposed
Standard), IETF E. Wedlund, and H. Schulzrinne, “Mobility Support using SIP” ACM WOWMOM workshop, Seattle, August 1999 F. Vakil, A. Dutta, J.-C. Chen, S. Baba, Y. Shobatake, H. Schulzrinne, “Mobility Management in a SIP Environment
Requirements, Functions and Issues”, Internet Draft March 2000, Work in Progress P. R. Calhoun, and J. Kempf, "Mobility Management and Authentication in an All-IP Network", mwif00.009, January
2000. ITSUMO Group, “ITSUMO’s All IP Wireless Architecture”, mwif00.012, January 14, 2000. A. McAuley, S. Das, and S. Baba, Y. Shobatake, “Dynamic Registration and Configuration Protocol for Mobile
Hosts”, <draft-itsumo-drcp-00.txt>, work in progress, October 1999. F. Vakil, A. Dutta, J.-C. Chen, S. Baba, and Y. Shobatake, “Host Mobility Management Protocol: Extending SIP to
3G-IP Networks”, <draft-itsumo-hmmp-00.txt>, work in progress, October 1999. S. Donavan, “ The SIP INFO Method” <draft-ietf-sip-info-method-03.txt>, March 2000, Work in Progress RFC 2004, IETF, “Minimal Encapsulation within IP” RFC 2002, IETF. “IP Mobility Support” RFC 2131, “Dynamic Host Configuration Protocol” Telcordia Technologies, “Voice Over Packet in Next Generation Networks: An Architectural Framework”, Bellcore
SR-4717, Issue 1, January 1999. ITSUMO Group, “Benchmarking of ITSUMO’s All IP Wireless Architecture”, mwif00.028, January 28, 2000. ITSUMO Group, “A Reference Architecture for All IP Wireless Networks”, 3GPP2-S00 allip-20000106-014, January
6, 2000. ITSUMO Group, “A Signaling Architecture for All IP Wireless Networks”, 3GPP2-S00allip-20000106-016, January 6,
2000. ITSUMO Group, “Evolution of Wireless Telephony towards Voice over 3G-IP”, 3GPP2- P00-19990824-010, to the
August 23, 1999.