home subscriber server (hss)
Post on 31-Dec-2015
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Home Subscriber Server(HSS)
By : M.Samie
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Home Subscriber Server
• What is HSS?• HSS in IMS• Main Data in HSS• HSS Subsets • HSS Logical Functions• Reference Points & Interfaces• Subscription Locator Function• Implementation Issues• Maintenance Issues
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What is HSS?
• Is the master database for a given user
• Containing the subscription-related information to support the network entities
• Is considered as Data Repository for IM CN Subsystem user related data
Note : A Home Network may contain one or several HSSs
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HSS in IMS
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IMS Functional Entities
VisitedVisitedNetworkNetworkVisitedVisited
NetworkNetwork
HSSHSSHSSHSSDNSDNSENUMENUMDNSDNS
ENUMENUM
I-CSCFI-CSCFI-CSCFI-CSCF S-S-CSCFCSCF
S-S-CSCFCSCF
Home Network
ASASASASASASASASASASASAS
Home Subscriber Server• Centralized DB• HLR successor• User profile• Filter criteria (sent to S-CSCF)
• Which applications• Which conditions
Home Subscriber Server• Centralized DB• HLR successor• User profile• Filter criteria (sent to S-CSCF)
• Which applications• Which conditions
Application Servers• Push-to-talk• Instant messaging• Telephony AS• 3rd party or IMS Vendor
Application Servers• Push-to-talk• Instant messaging• Telephony AS• 3rd party or IMS Vendor
P-P-CSCFCSCF
P-P-CSCFCSCF
MGCFMGCFMGCFMGCF
MGWMGWMGWMGWPSTNPSTNPSTNPSTN
H.248
ISUPBGCFBGCFBGCFBGCF
SIP
SS7SS7SS7SS7
SIP
SIP
SIP
SIP
SIPSIP
SIP
Diameter
RTP TDM
MSMSMSMS MSMSMSMS
MRFCMRFCMRFCMRFC
Media GatewayControl Function• Interfaces to PSTN/PLMN by
• Converting SIP <-> ISUP• Interworking RTP to circuit
• H.248 control of MGW
Media GatewayControl Function• Interfaces to PSTN/PLMN by
• Converting SIP <-> ISUP• Interworking RTP to circuit
• H.248 control of MGW
Breakout Gateway Control Function• Selects network (MGCF or other BGCF) in which PSTN/ PLMN breakout is to occur
Breakout Gateway Control Function• Selects network (MGCF or other BGCF) in which PSTN/ PLMN breakout is to occur
Media Resource Function Controller• Pooling of Media servers (e.g. conference) Media Resource Function Controller• Pooling of Media servers (e.g. conference)
Proxy CSCF• 1st contact point for UA• QoS• Routes to S-CSCF
Proxy CSCF• 1st contact point for UA• QoS• Routes to S-CSCF
Interrogating CSCF• Entry point for incoming calls• Determines S-CSCF for Subscribers• Hides network topology
Interrogating CSCF• Entry point for incoming calls• Determines S-CSCF for Subscribers• Hides network topology
Serving CSCF• Registrar• Session control• Application Interface
Serving CSCF• Registrar• Session control• Application Interface
P-P-CSCFCSCF
P-P-CSCFCSCF
SIP
SIP
UA/UE
UA/UE
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Home Subscriber Server
• What is HSS?• HSS in IMS• Main Data in HSS• HSS Subsets • HSS Logical Functions• Reference Points & Interfaces• Subscription Locator Function• Implementation Issues• Maintenance Issues
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Main Data in HSS
• Presence, Location and Profile• End-User Identity• Private and Public End-User
Information• Registration Information• Service Initiation Information• Subscriber Service Profile (SSP)
• Downloaded to CSCF at Registration
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HSS Subsets
• Home Location Register (CS Domain)
• Home Location Register (PS Domain)
• Authentication Center (CS Domain)
• Authentication Center (PS Domain)
• IMS related subset
CS Domain
PS Domain
IM C
N
HLR
HLR
AUC
AUC
DR
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Home Location Register
• It is needed to enable subscriber access to the PS Domain services.
• It supports PS Domain entities such as the SGSN and GGSN, through the Gr and Gc interfaces and the 3GPP AAA Server for the I-WLAN through the D'/Gr' interface.
• It is needed to enable subscriber access to the CS Domain services and to support roaming to legacy GSM/UMTS CS Domain networks.
• It supports CS Domain entities such as the MSC and GMSC, through the C and D interfaces.
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Authentication Center
• The AuC is associated with an HLR and stores an identity key for each mobile subscriber registered with the associated HLR.
• The AuC communicates only with its associated HLR over a non-standardised interface denoted the H-interface.
• The HLR requests the data needed for authentication and ciphering from the AuC via the H-interface.
• HLR delivers them to the VLR and SGSN which need them to perform the security functions for a mobile station.
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Home Subscriber Server
• What is HSS?• HSS in IMS• Main Data in HSS• HSS Subsets • HSS Logical Functions• Reference Points & Interfaces• Subscription Locator Function• Implementation Issues• Maintenance Issues
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HSS
Mobility Management
CSCFIM-SSFOSA-SCS
GGSNSGSNGMSC MSC/VLR
PS DomainCS Domain IM CN Subsystem
Applications
GUP Server
AAA Server
SIP Application Server
Identification Handling
User Security Info Generation
Service Authorization
User Security Support Access Authorization
Service Provisioning Support
Application Services Support
Call/Session Establishment Support
CAMEL Services Support
GUP Data Repository SNMP Agent function Support
CxSiShShRp
Rp
Wx, Gr’, Gc’
GcGrDC
3GPP TS 23.002
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HSS Logical Functions
• Mobility Management HSS supports MM by location updating
• Call Session Establishment Support HSS provides information on which
call/session control entity currently hosts the user
• User Security Support The HSS generates user authentication and
ciphering data for the CS and PS Domains and for the IM CN subsystem.
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HSS Logical Functions(Cont.)
• User Identification HandlingThe HSS provides the appropriate relations among
all the identifiers uniquely determining the user in the system
CS Domain (IMSI and MSISDNs) PS Domain (IMSI, MSISDNs and IP addresses) IM CN subsystem (private identities and public
identities)
• Access AuthorizationThe HSS authorises the user for mobile access
when requested by the MSC/VLR, SGSN, 3GPP AAA Server or CSCF, by checking that the user is allowed to roam to that visited network.
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HSS Logical Functions(Cont.)
• Service Authorization SupportThe HSS provides basic authorisation for MT call/session
establishment and service invocation.
The HSS updates the appropriate serving entities (i.e., MSC/VLR, SGSN, 3GPP AAA Server, CSCF) with the relevant information related to the services to be provided to the user.
• Service Provisioning Support The HSS provides access to the service profile data for
use within the CS Domain, PS Domain and IM CN subsystem.
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HSS Logical Functions(Cont.)
• Application Service and CAMEL Service Support
The HSS communicates with the SIP Application Server and the OSA-SCS to support Application Services in the IM CN subsystem.
The HSS communicates with the IM-SSF to support the CAMEL Services related to the IM CN subsystem.
The HSS communicates with the gsmSCF to support CAMEL Services in the CS Domain and PS Domain.
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HSS Logical Functions(Cont.)
• GUP Data Repository The HSS supports the storage of IM CN
Subsystem user related data, and provides access to these data through the Rp reference point by GUP Server*.
* GUP Server is a functional entity providing a single point of access to the Generic User Profile data of a particular subscriber. (TS 23.240)
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Home Subscriber Server
• What is HSS?• HSS in IMS• Main Data in HSS• HSS Subsets • HSS Logical Functions• Reference Points & Interfaces• Subscription Locator Function• Implementation Issues• Maintenance Issues
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HSS and Basic Interfaces
MSC
GMSC SGSN
GGSN
CSCF GUP Server
HSSD
CGr
Gc
Cx Rp
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Reference Points & Interfaces
• Interfaces internal to the CS domain• Interfaces internal to the PS domain• Interfaces used by CS and PS
domains • IM Subsystem Reference Points• Diameter Protocol
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Interfaces to CS domain
HLR - VLR (D-interface)(TS 29.002)
Is used to exchange the data related to the location of the mobile station and the management of the subscriber.
Signalling on this interface uses the Mobile Application Part (MAP), which in turn uses the services of Transaction Capabilities.
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Interfaces to CS domain
HLR - MSC (C-interface) (TS 29.002)
The Gateway MSC must interrogate the HLR of the required subscriber to obtain routing information for a call or a short message directed to that subscriber.
Signalling on this interface uses the Mobile Application Part (MAP), which in turn uses the services of Transaction Capabilities.
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Interfaces to PS domain
HLR – SGSN (Gr-interface)(TS 29.002)
This interface is used to exchange the data related to the location of the mobile station and to the management of the subscriber.
Signalling on this interface uses the Mobile Application Part (MAP), which in turn uses the services of Transaction Capabilities.
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Interfaces to PS domain
HLR – GGSN (Gc-interface)(TS 29.002)
Is used by the GGSN to retrieve information about the location and supported services for the mobile subscriber, to be able to activate a packet data network address.
Signalling on this interface uses the Mobile Application Part (MAP), which in turn uses the services of Transaction Capabilities.
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Interfaces used by CS and PS domains
HLR - AuC (H-interface)When an HLR receives a request for
authentication and ciphering data for a Mobile Subscriber and it does not hold the requested data, the HLR requests the data from the AuC.
The protocol used to transfer the data over this interface is not standardised.
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Reference Points & Interfaces
• Interfaces internal to the CS domain• Interfaces internal to the PS domain• Interfaces used by CS and PS
domains • IM Subsystem Reference Points• Diameter Protocol
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IM Subsystem Reference Points
• HSS – CSCF (Cx Reference Point)• HSS – SIP AS or OSA SCS (Sh Reference Point)• HSS – CAMEL IM-SSF (Si Reference Point) • AAA Server - HLR (D'/Gr' Reference Point)• AAA Server - HSS (Wx Reference Point)• GUP Server – HSS (Rp Reference Point)• Applications – HSS (Rp Reference Point)• CSCF- SLF (Dx Reference Point) • AS- SLF (Dh Reference Point)• AAA Server - SLF (Dw reference point)
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IM Subsystem Reference Points
HSS – CSCF (Cx Reference Point) (TS 23.228)
Procedures related to Serving CSCF assignment
Procedures related to routing information: retrieval from HSS to CSCF
Procedures related to authorisation (e.g., checking of roaming agreement)
Procedures related to authentication: transfer of security parameters of the subscriber between HSS and CSCF
Procedures related to filter control: transfer of filter parameters of the subscriber from HSS to CSCF
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IM Subsystem Reference Points
AAA Server - HSS (Wx Reference Point)AAA Server - HLR (D'/Gr' Reference Point)
(TS 23.234)
Retrieval of authentication vectors
Retrieval of WLAN access-related subscriber information (profile)
Registration of the 3GPP AAA Server of an authorised WLAN user in the HSS
Indication of change of subscriber profile
Retrieval of online/offline charging
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IM Subsystem Reference Points
GUP Server – HSS Applications – HSS (Rp Reference Point)
(TS 23.240)
Enables the GUP Server and the Applications to access GUP Data Repositories
The HSS is one of the GUP Data Repositories. It stores the IM CN Subsystem user related data.
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Reference Points & Interfaces
• Interfaces internal to the CS domain• Interfaces internal to the PS domain• Interfaces used by CS and PS
domains • IM Subsystem Reference Points• Diameter Protocol
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Diameter Protocol
• Is a signaling protocol that has been specified by IETF (RFC 3588 – 3589)
• IS defined as a base protocol used in conjunction with a set of applications
• It provides mechanisms for reliable transport, message delivery and error handling between Diameter clients and servers.
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Diameter Functions
• Delivery of AVPs (Attribute Value Pair)• Capabilities negotiation• Error notification• Basic Services necessary for applications,
such as handling of user sessions or accounting
Note : Diameter can be extended through addition of new commands and AVPs for set of new application requirements
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Home Subscriber Server
• What is HSS?• HSS in IMS• Main Data in HSS• HSS Subsets • HSS Logical Functions• Reference Points & Interfaces• Subscription Locator Function• Implementation Issues• Maintenance Issues
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Subscription Locator Function
(SLF)
Is used as a resolution mechanism that enables the I-CSCF, the S-CSCF and the AS to find the address of the HSS that holds the subscriber data for a given user identity when multiple and separately addressable HSSs have been deployed by the network operator.
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IM Subsystem Reference Points
CSCF- SLF (Dx Reference Point) AS- SLF (Dh Reference Point)
AAA Server - SLF (Dw reference point)(TS 23.228)
Is used to retrieve the address of the HSS which holds the subscription for a given user.
Is not required in a single HSS environment.
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Home Subscriber Server
• What is HSS?• HSS in IMS• Main Data in HSS• HSS Subsets • HSS Logical Functions• Reference Points & Interfaces• Subscription Locator Function• Implementation Issues• Maintenance Issues
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Implementation Issues
• In IMS arch. the HSS is a central database that contains all of the information needed to properly control sessions.
• Functions in the network interact with the HSS using IETF Diameter Protocol.
• The HSS is involved in every session and maybe queried multiple times during a call so it must have high performance.
• The HSS must be exceptionally reliable, as without it sessions cannot be created.
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Implementation Issues• Software Modules
Agents supports protocols and Interfaces Information Storage & Retrieval Module Agents supports authorization requested by
components Other functions inherited from PS & CS domains
• Data Organization Storage Media
■ Memory Hierarchy■ Efficient/Reliable Transfer
– Hardware Techniques ( RAID disks )– Software Techniques ( Buffer Mgmt )
Storage Strategies■ Tuples on Disks■ Tuples on Pages, Clusters, …
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Home Subscriber Server
• What is HSS?• HSS in IMS• Main Data in HSS• HSS Subsets • HSS Logical Functions• Reference Points & Interfaces• Subscription Locator Function• Implementation Issues• Maintenance Issues
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Maintenance Issues
• The main issue is adding capacity while maintaining performance
Simply adding processing power on HSS Adding additional mirror database nodes either at
the same location or distributed geographically Segregating different groups of subscribers in
different databases
Result is a network that seamlessly support growth to millions call per “Busy Hour” without stressing any single point in the network
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Any Question?
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Data in HSSThe main data stored in the HSS include [3GPP
TS 23.002]: User identities
private user identities public user identities
registration information access parameters
user authenticationallocated S-CSCF names roaming authorization
service-triggering information
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Subscriber Data
• Subscriber data for CS and PS domains• Subscriber data for IP Multimedia
domain
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Subscriber data for CS and PS domains
(TS 23.008)• Data related to subscription, identification and numbering • Data related to Mobile Station types• Data related to authentication and ciphering • Data related to roaming • Data related to basic services• Data related to supplementary services • Mobile station status data • Data related to Operator Determined Barring • Data related to handover• Data related to short message support • Data related to subscriber trace • Data related to the support of voice group and broadcast calls• Data related to GPRS NAM • Data related to CAMEL• Data related to charging
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Subscriber data for IP Multimedia domain
(TS 23.008) • Data related to subscription, identification and
numbering • Data related to registration • Data related to authentication and ciphering • Data related S-CSCF selection information • Data related to Application and service triggers • Data related to Core Network Services
Authorization• Data related to Charging • Data related to CAMEL Support of IMS Services
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