tekelec - dra_diameter and dsr overview.pdf
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7/17/2019 TEKELEC - DRA_Diameter and DSR Overview.pdf
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This document is for informational purposes only, and Tekelec reserves the right to change any aspect of the products, features or
functionality described in this document without notice. Please contact Tekelec for additional information and updates.
Overview
EAGLE XG
Diameter and Diameter Signaling Router
Carlos Arias Fernandez
Tekelec. For What’s Next.
March 2012
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Agenda
› Diameter Overview
› Use of Diameter in LTE/IMS/3G
› DSR Use Cases
Core Relay/Proxy 3G/LTE/IMS
S6/S9 Roaming Proxy (Diameter Edge Agent) LTE/IMS
Policy Proxy 3G/LTE/IMS (Gx/Gxx/Rx/S9)
HSS Proxy LTE/IMS (S6/Cx/Dx/Sh/Dh)
Charging Proxy 3G/LTE/IMS (Rf/Gy/Ro)
Tekelec Confidential2 I Tekelec. For What’s Next.
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Diameter
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Session Management
› Diameter and SIP become the dominant signaling protocols
› SCTP “point-to-point” connections remain
Mobility and Subscriber Management
Application and Session Control
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Diameter Comparison to SS7
Tekelec Confidential5 I Tekelec. For What’s Next.
Characteristic SS7 Diameter
Routing › Each message independently routed
› Answer message does not contain
routing info and follows same path
as associated request
Signaling network management
(SNM) and Congestion control
› Network-wide
› Dedicated SNM msgs
› Route around failed paths
› Congestion levels and traffic
priorities defined
› Hop-by-hop
› No dedicated SNM msgs
› Failures „discovered‟ with each new
request
› Relies on reliable transport
› No defined traffic priorities
Subscriber number based routing › GTT can be used by upper layers
› Specialized, app-specific proxies
required
DRA for PCRF
HSS address resolution for EPC and
IMS
Robustness› Wide-scale deployment; years of
experience
› Early days; lots of prove-in still
required
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Example Diameter Message – Update Location
6 I Tekelec. For What’s Next.
MME
AAA
HSS
Update LocationS6a
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Example Diameter Message – Update Location
7 I Tekelec. For What’s Next.
MME
AAAHSS
Update LocationS6a
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Example Diameter Message – Update Location
8 I Tekelec. For What’s Next.
MME
AAAHSS
Update LocationS6a
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Use of Diameter in LTE/IMS/3G
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Selected Diameter Interfaces in 3G, LTE and IMS
Interface Endpoints
S6a MME HSS
S6d HSS vSGSN (Rel 8)
S13 MME EIR
S9 hPCRF vPCRF
Rx PCRF AF, P-CSCF
Gx PGW PCRF
Gy PGW OCF
Gz PGW OFCF
Cx I/S-CSCF HSS
Sh AF, IP-SM-GW HSS
Rf P/I/S-CSCF, AF OFCF
Ro S-CSCF, AF OCF
Rc OCF ABMF
Re OCF RF
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Selected Diameter Interfaces in LTE (EPC) and IMS
Foreign LTE Domain
Home LTE/IMS Domain
Foreign GPRS Domain
S13
S6a S9S6d
GxGz
Gy
Cx
Sh
Rx
Ro
Rf
Rc Re
EIR
vMME vPCRF
PGW
AF
ABMF RF
OFCF
MAP-Diam
IWF
vSGSN
vS4-SGSN
OCF
EPC Equipment
Check
AS Access
to HSS
IMS PCC
IMS
Charging
EPC
Charging
IMS
Registration
EPC Mobility
Management
MME
I/S-CSCFPCRF
P-CSCF
IP-SM-GWAAAHSS
SLF
Gr
Policy
SPR
Sh
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Diameter Agents in 3GPP and GSMA
› 3GPP TR 29.909 – Diameter-based
protocols usages and recommendations
in 3GPP
Defines need for Diameter infrastructure
to simplify the S6 and S9 network
› 3GPP TS 23.203 – Policy and charging
control architecture
Defines Diameter routing agent to direct
all messages for the same IP-CAN
session to the same PCRF
› GSMA PRD IR.88 – LTE Roaming
Guidelines
Defines need for a Diameter agent at the
point of network demarcation
Tekelec Confidential13 I Tekelec. For What’s Next.
Border Diameter
Relay Pool
Inter-operator Diameter
Infrastructure
Inner Diameter
Relay Pool
S4
SGSN
vPCRF
VPMN HPMN
Proxy
Agent
hPCRF
Proxy
Agent
S6a
S6d
S9
GRX/IPX
S-GW
P-GW
Non-3GPP
GW
ePDG
AF
Gx, Gxa, Gxb, Gxc, Rx
Diameter (PCRF) realm
DRADRA
Diameter (PCRF) realm
DRADRA
PLMN
MME MME MME
MME
PCRF
PCRF
HSS
HSS
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Scalability and
Connection
Management
Centralized
Routing and
Load Sharing
Network
VisibilityCentralized
Failover Models
TCP/SCTP
Interworking
Diameter
Variant
Mediation
Network-wide
PCRF Binding
Roaming
Steering
MAP/Diameter
Interworking
HSS/MME/PCRFTopology Hiding
IPsec
Core Relay/Proxy
3G/LTE/IMS
(all interfaces)
Policy Proxy
3G/LTE/IMS
(Gx/Gxx/Rx/S9)
Roaming Proxy
LTE/IMS
(S6/S9)
HSS Proxy
LTE/IMS
(S6/Cx/Dx/Sh/Dh)
14 I Tekelec. For What’s Next. Tekelec Confidential
OCS/OFCS
Session-based
Routing
Charging Proxy
3G/LTE/IMS
(Rf/Gy/Ro)
OCS/OFCS
Topology HidingPCRF
Topology Hiding
Tekelec DSR - A Multi-application Diameter Agent
HSSOCS/OFCS
PCRF
Agent
GGSN
PGWMME CSCF
Other
Networks
IMS HSS
Address
Resolution
LTE HSS
Address
Resolution
HSS
Topology Hiding OCS/OFCS
Address
Resolution
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Core Relay/Proxy 3G/LTE/IMS
Use Cases
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Scalability and
Connection
Management
Centralized
Routing and
Load Sharing
Network
VisibilityCentralized
Failover Models
TCP/SCTP
Interworking
Diameter
Variant
Mediation
Core Relay/Proxy
3G/LTE/IMS
(all interfaces)
16 I Tekelec. For What’s Next. Tekelec Confidential
Core Relay
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Scalability and connection Management
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Use Case - 3G Mobile Data Architecture
Tekelec Confidential18 I Tekelec. For What’s Next.
Gx+ and Gy
DRALB
DRALB
DRALB
DRALB
DRALB
DRALB
SBCF/ABMF
SBCF/ABMF
SBCF/ABMF
SBCF/ABMF
SBCF/ABMF
SBCF/ABMF
10 PCRF‟s/Site
8 SBCF‟s/Site
10 PCRF‟s/Site
8 SBCF‟s/Site
10 PCRF‟s/Site
8 SBCF‟s/Site
Load balancers
can vary from
connection
balancers to
specialized
Diameter proxies
GGSN
GGSN
GGSN
GGSN
GGSN
GGSN
GGSN
GGSN
GGSN
GGSN
GGSN
GGSN
GGSN
PCRF
PCRF
PCRF
PCRF
PCRF
PCRF
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Use Case - 3G Mobile Data Net with Diameter Relay
Tekelec Confidential19 I Tekelec. For What’s Next.
SBCF/ABMF
SBCF/ABMF
SBCF/ABMF
10 PCRF‟s/Site
8 SBCF‟s/Site
10 PCRF‟s/Site
8 SBCF‟s/Site
10 PCRF‟s/Site
8 SBCF‟s/Site
Enables future
separation of SBCF
and ABMF via
Diameter
interconnect
Addresses connection
limitations at GGSN
Eliminates need for
load balancers in front
of PCRFs and SBCFs
SBCF/ABMF
SBCF/ABMF
SBCF/ABMF
GGSN
GGSN
GGSN
GGSN
GGSN
GGSN
GGSN
GGSN
GGSN
GGSN
GGSN
GGSN
GGSN
PCRF
PCRF
PCRF
PCRF
PCRF
PCRF
DSR
DSR
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One Region Initial Configuration
MME
MME
MME
HSS Mated Pair
HSS1-Site A
HSS1-Site B
DSR
DSR
• Assumes 2M capacity of MME
• Assumes 6M capacity of HHS
• 4 MME-DSR connections -
NEVER NEED TO CHANGE
• 4 DSR-HSSFE connections -
ONLY CHANGE W ITH HSS
ARCH/CAPACITY CHANGES,
NOT WITH MME CHANGES
MME
MME
MME
FE
FE
DB
DB
HSS Mated Pair
HSS1-Site A
HSS1-Site B
DB
DB
FE
FE
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Expand Region to 2 HSS’s with HSS DRA
MME
MME
MME
HSS Mated Pair
HSS1-Site A
HSS1-Site B
Required new connections
Potential new connections to
reduce HSS FE Relay load
DB
DB
HSS Mated Pair
HSS2-Site A
HSS2-Site B
DB
DB
MME
MME
MME
FE
FE
FE
FE
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Expand Region to 2 HSS’s with DSR
MME
MME
MME
HSS Mated Pair
HSS1-Site A
HSS1-Site B
Required new connections
DB
DB
HSS Mated Pair
HSS2-Site A
HSS2-Site B
DB
DB
MME
MME
MME
DSR
DSR
FE
FE
FE
FE
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Expand Region to 3 HSS’s with HSS DRA
MME
MME
MME
HSS Mated Pair
HSS1-Site A
HSS1-Site B
Required new connections
Potential new connections to
reduce HSS FE Relay load
DB
DB
HSS Mated Pair
HSS2-Site A
HSS2-Site B
DB
DB
MME
MME
MME
H S S M a t e d P ai r
HSS3-Site A
HSS3-Site B
DB
DB
MME
MME
MME
FE
FE
FE
FE
FE
FE
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Expand Region to 3 HSS’s with DSR
MME
MME
MME
Required new connections
MME
MME
MME
DSR
DSR
H S S M a t e d P ai r
HSS2-Site A
HSS2-Site B
DB
DB
H S S M a t e
d P ai r
HSS1-Site A
HSS1-Site B
DB
DB
H S S M a t e d P ai r
HSS3-Site A
HSS3-Site B
DB
DB
MME
MME
MME
FE
FE
FE
FE
FE
FE
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The HSS Mesh - Network View
Site 1-ABC
HSSA HSSB HSSC
Site 2-ABC
HSSA HSSB HSSC
S i t e 1 - M N O
H S S M
H S S N
H S S O
S i t e2 -DE F
H S S D
H S S E
H S S F
Site 1-JKL
HSSJ HSSK HSSL
Site 2-GHI
HSSG HSSH HSSI
This blue lines represent one HSS‟s
connections to all other HSS‟s but its
mate (28 connections assuming only asingle connection between HSS‟s is
sufficient). All HSS‟s will have at least one
connection to all other HSS‟s except it‟s
mate, for a minimum of 840 connections
for 15 mated pairs of HSS‟s.
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The DSR Mesh - Network View
Site 1-ABC
HSSA HSSB HSSC
Site 2-ABC
HSSA HSSB HSSC
S i t e 1 - M N O
H S S M
H S S N
H S S O
S i t e2 -DE F
H S S D
H S S E
H S S F
Site 1-JKL
HSSJ HSSK HSSL
Site 2-GHI
HSSG HSSH HSSI
DSR DSR
DSR DSR
D S R D
S R
This blue lines represent one DSR‟s
connections to all other DSR‟s (9
connections assuming only a singleconnection between DSR‟s is
sufficient). All DSR‟s will have at least
one connection to all other DSR‟s, for
a minimum of 90 connections for 5
mated pairs of DSR‟s.
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Message Handling
DSR R ti T bl
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DSR Routing Tables
› An important feature of DSR is the ability to support local applications such as PolicyDRA and HSS Address Resolution in 3GPP networks.
› Local applications may be invoked when a Request message is first received from a
downstream peer, prior to invoking message routing to an upstream peer. To facilitatethis two step process, two routing table have been defined:
Application Routing Table (ART) - contains a prioritized list of user-configurable routing ruleswhich define which local applications to invoke and in which order based upon messagecontent
Peer Routing Table (PRT) - contains a prioritized list of user-configurable routing rules whichdefine where to route a message to an upstream peer based upon message content
A PRT rule can be associated with a Route List which contains a prioritized list of peers usedto route a Request message.
Peer
N-1
Peer
N+1
Appl-1 Appl-2
ApplicationRouting
Table
Peer Routing
Table
RouteList
Table
(2) (3)
(4) (5) (6)
UpstreamDownstream DSR
(1)
Request
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DSR R ti R t R ti P t
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DSR Routing – Request Routing Parameters
› DSR allows the operator to define routing rules based on combinationsof the following data elements:
Destination-Realm (leading/trailing characters, exact match or wildcard)
Destination-Host (leading/trailing characters, exact match, wildcard orpresence/absence)
Application-ID (exact match or wildcard).
› In addition to the above, the following data elements are supported in
DSR to facilitate screening, application invocation, and enhancedrouting:
Command-Code (exact match or wildcard)
Origin-Realm (leading/trailing characters, exact match or wildcard)
Origin-Host (leading/trailing characters, exact match or wildcard)
› DSR allows the operator to prioritize rules for cases where a DiameterRequest may match multiple user defined rules
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E l P R ti i RT d R t Li t
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Example – Peer Routing using RT and Route Lists
Routing Table (RT)
Dest-Realm* Orig-Realm* Appl ID* Dest-Host* Orig-Host*Cmd-
Code*Action
Route List
NamePri
opco1.com homeop.com Don‟t care Don‟t care Don‟t care Route toPeer HUB_NW 1
opco2.com homeop.com Don‟t care Don‟t care Don‟t careRoute to
Peer OPCO2_NW 1
homeop.com opco1.com 43 Don‟t care Don‟t careRoute to
Peer HSS1 1
homeop.com opco2.com 65 Don‟t care Don‟t careRoute to
Peer MME2 1
Don‟t care Don‟t care Don‟t care Don‟t care Don‟t care Send Answer“X”
--- 99
Route List Table
Route List Name Route Name Pri Weight
HUB_NW HUB_PEER1 1 60
HUB_NW HUB_PEER2 1 40
HUB_NW HUB_PEER3 2 50
HUB_NW HUB_PEER4 2 50
OPCO2_NW OPCO2_PEER1 1 100
OPCO2_NW OPCO2_PEER2 2 100
HHS1 HSS1_SRV1 1 100
MME1 MME1_SRV1 1 100
MME1 MME1_SRV2 2 100
Active Route Group
Standby Route Group
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M lti l R t G i R t Li t C t l Vi
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Multiple Route Groups in a Route List – Conceptual View
Peer1
Peer2
Peer3
Peer4
Peer5
Peer6
Peer7
W=40
W=30
W=30
W=60
W=40
W=50
W=50
Route Group-1
(Routes with Pri=1)
Route Group-2(Routes with Pri=2)
Route Group-3(Routes with Pri=3)
DSR
Route List-1
Route Group-1
Route Group-2
Route-1, Pri=1, Wt=40, Peer=1
Route-2, Pri=1, Wt=30, Peer=2
Route-1, Pri=2, Wt=60, Peer=4Route-2, Pri=2, Wt=40, Peer=5
Route Group-3
Route-1, Pri=3, Wt=50, Peer=6
Route-2, Pri=3, Wt=50, Peer=7
Route-3, Pri=1, Wt=30, Peer=3
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R t M R R ti B d St d d Di t
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Client
Target
DSR
Server
DSR
Agent
Agent
1
3
2
4
56
Client
DSR
Server
DSR
Target
DSR
DSR
12
4
5
Client
Target
DSR
Server
DSR
Agent
Agent
12
3
45
Timeout
Request Message Re-Routing – Beyond Standard Diameter
Alternate Routing on Answer
Configurable per Result Code
Alternate routing on transport failure
Connection failure occurs aftermessage 3 has been sent
T-bit set on re-routed message towarn of possible duplicate
Alternate routing on timeout
No response received formessage 2
T-bit set on re-routed message towarn of possible duplicate
3
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DIAMETER Mediation
Di t R l E i
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Diameter Rules Engine
MME IP Cloud
36 | Tekelec. For What's Next. Tekelec Confidential
HSS FEDiameter
Variant 1Diameter
Variant 2
Mediation and Advanced Routing
Not My Fault Not My Fault
Diameter Mediation via Rules Engine
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Diameter Mediation via Rules Engine
Peer
N-1
Peer
N+1
Local
Appl
ART/PRTRoute
List Table
(2) (3)
(4) (5)
DSR
(1)
Request
Answer
Processing
(6) Answer (8) Answer
In-line 3rd
Party App
Off-line
3rd Party App
(4‟)
Conditions logically AND‟d or OR‟d:
• Origin/Destination Host/Realm
presence, value match, partialvalue/range match
• Header fields (Appl-ID, CmdCode,
flags, etc.) value match
• Application specific AVPs
presence, value match, partial
value/range match
Actions:
• Add AVP
• Delete AVP
• Modify AVP• Modify header field
• Route to Local App
• Route to Peer via Route-List
• Send Answer with specified
Result-Code
• Copy message/session
Diameter Rules Engine
trigger points – trigger
one or more tasks, with
priority
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Mediation Conditions
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Mediation – Conditions
› The DSR must evaluate conditions provisioned by the operator
before attempting to perform mediation
› The conditions can be “ ANDed” and include checking for
Origin-Host/Realm (begins with, ends with, any or exact match)
Destination-Host/Realm (begins with, ends with, any, present, absent
or exact match)
Command Code (exact match or any)
Application ID ( exact match or any)
If the request traversed a certain host (i.e hostname present in route-
record)
If the request includes a certain AVP (check attribute name) If the request does not include a certain AVP (check attribute name)
Ability to check for the value of a certain AVP
And so on…
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Mediation Actions Supported
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Mediation – Actions Supported
› Add AVP
The Attribute Value can be specified or derived based on anotherattribute value present in the message
› Delete AVP
The AVP code (Attribute Name or free format) is specified by theoperator
• Delete specific instance or all instances
› Modify Header – CC, Appl-ID, Flags› Modify AVP code (Attribute Name)
› Modify AVP flags – Set/Reset/Toggle
› Modify Value of a specific AVP code
The AVP code is specified by the operator
The Attribute Value can be specified or can be derived based on itscurrent value or derived from another attribute value present in themessage
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3rd Party Application Support
3rd Party Application Support
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3rd Party Application Support
Peer
N-1
Peer
N+1
PeerRoutingTable
RouteList
Table
(2)
(3) (4)
UpstreamDownstream
DSR
(1)
Request
AnswerProcessing
(5) Answer (6) Answer
In-line3rd Party
Appl
Off-line3rd Party
Appl
Receives a copy ofcomplete Diameter
message and performs
processing
Several options for App
server:
• Redirect server
• Special redirect server
returning encapsulated msg
• B2BUA
• Proxy/Relay (requires
special processing at DSR to
suppress loop detection)
(3‟)
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In line App Server as a Special Proxy/Relay
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In-line App Server as a Special Proxy/Relay
The DAS routes the original
request, perhaps with
modifications, back through theDSR
The new request (msg #3) has a
new Hop-by-Hop ID
The End-to-End ID is unchangedby the DAS
To prevent loop detection, the
DAS does NOT add DSR to the
“Route-Record” before sending
out msg #3 The DAS must maintain
transaction state and relay the
answer msg #6
DSR
DAS
1
2
3
4
5
6
7
8
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In line App Server as a Special Redirect Server
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In-line App Server as a Special Redirect Server
This method is used when theDAS wants to drop out of the Answer path
This is a future case, post DSR 2.0
The DAS returns a Redirectresponse with the original,perhaps modified, Request
encapsulated (in a mutuallyagreed AVP)
The DSR extracts theencapsulated Request and routesit, factoring the Ingress Peer (i.e.DAS) into the routing decision
The DAS will not see the Answermsg #5
DSR
DAS
1
2
4
5
3
6
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In-line App Server as a B2BUA
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In-line App Server as a B2BUA
DAS responds with an Answerto an incoming Request and
originates a new Request
The hop-by-hop id and more
importantly the End-to-End id in
the inbound and outboundRequests are different
The two Requests are only
logically related at the DAS
Supported in DSR 2.0
DSR
DAS
1
2
3
4
5
6
7
8
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In-line App Server as a Standard Redirect Server
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In-line App Server as a Standard Redirect Server
DAS responds with an
Answer (Result-Code 3006)to an incoming request
The Answer includes a
“Redirect-Host” AVP
indicating the destination
host the message should berouted towards
The DSR uses the contents
of the “Redirect-Host” AVP to
route the Request
Supported post DSR 2.0
DSR
DAS
1
2
4
5
3
6
45 I Tekelec. For What’s Next.Tekelec Confidential
Off-line App Server
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Off-line App Server
DAS receives copy of
Request (1‟) and, optionally,
the associated Answer (4‟)
DSR does not maintain
transaction state for copied
Requests (any Answers
received from DAS are
discarded)
Supported post DSR 2.0DSR
DAS
1
1‟
2
34
4‟
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Peer Overload and Flow Control
Remote Congestion Control
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Remote Congestion Control
› Peer Transport Congestion Control via the transmit queue
When queue level exceeds a user-configurablethreshold, the transport connection is markedcongested
New Requests must use an alternate route
Answer messages are unaffected› Peer Transport Congestion Control using Answers
Answer contains the DIAMETER_TOO_BUSY Result-Code
Optionally mark connection congested for a user-configurable time
Answer messages are unaffected
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Message Throttling
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Message Throttling
› To assist with prevention of Diameter peer overload, DSR
provides a method for throttling the volume of DiameterRequest traffic sent to peers based on Request content.
› For example, a registration storm resulting from an HSS failure
could result in the remaining HSS nodes becoming
overloaded.
In this scenario, having the capability to throttle the rate of certain
message types routed to the HSS may effectively prevent the HSS
from becoming overloaded.
Selection of the traffic to be throttled leverages the Peer Routing
Table (PRT) described earlier, allowing a combination of Appl-ID,
Command-Code, Destination-Realm, Destination-Host, Origin-
Realm, and Origin-Host.
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Diameter Intelligence Hub
Network Visibility
Diameter Intelligence Hub Features
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Diameter Intelligence Hub Features
› Tracing Trace nodal transactions across DSR and between other network elements (e.g., other
DSRs, HSSs, MMEs)
Full decode of Diameter payload Display trace output in ladder diagram
Extensive tracing filters available (e.g., IMSI, SGSN, etc.)
› Data Feed of xDR records NFS and (S)FTP supported
Correlated records can be exported to any external server
› Filtering View actual traffic as xDRs
Filter through traffic to pinpoint issues
› Alarms Alarm forwarding for DIH system alarms via SNMP/email
› Configuration and provisioning
Web-based GUI providing security, configuration, and application access for DIH› Collection and Storage Create and store unique records for each desired transaction (PDUs, xDRs)
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S6/S9 Roaming Proxy (Diameter Edge Agent) LTE/IMS
Use Cases
S6/S9 Roaming Proxy (Diameter Edge Agent)
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Roaming
Steering
MAP/Diameter
Interworking
HSS/MME/PCRF
Topology Hiding
Core Relay/Proxy
3G/LTE/IMS
(all interfaces)
Roaming Proxy
LTE/IMS
(S6/S9)
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S6/S9 Roaming Proxy (Diameter Edge Agent)
Scalability and
Connection
Management
Centralized
Routing and
Load Sharing
Network
VisibilityCentralized
Failover Models
TCP/SCTP
Interworking
Diameter
Variant
Mediation
MME Topology Hiding (MME Binding)
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MME Topology Hiding (MME Binding)
2) Update-Location-Request
• Origin_Host = MME_Public
• Origin_Realm = Op1.NET
• Destination_Realm = Op2.NET• User-Name = IMSI_1
Current
Serving
MME
Previous
Serving
MME
IMSI
MME1 MME2 IMSI_1
1) Update-Location-Request
• Origin_Host = MME1
• Origin_Realm = Op1.NET
• Destination_Realm = Op2.NET
• User-Name = IMSI_1
Gateway
DSR
MME 1 MME 2
MME <> IMSI
Mapping
HSS
DSR replaces MME ID with genericID and saves the mapping of
IMSI <> Current MME and
Previous MME. Mapping must
be shared with mate(s) as well.
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MME Topology Hiding
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2) Cancel-Location-Request• Origin_Host = HSS1
• Origin_Realm =Op2.NET
• Destination Host = MME2
• Destination Relam = Op1.NET• User-Name = IMSI_1
3) Cancel-Location-Answer
• Origin_Host = MME2
• Origin_Realm = Op1.NET
• User-Name = IMSI_1
4) Cancel-Location-Answer
• Origin_Host = MME_Public
• Origin_Realm = Op1.NET
• User-Name = IMSI_1
1) Cancel-Location-Request
• Origin_Host = HSS1• Origin_Realm =Op2.NET
• Destination Host = MME_Public
• Destination Relam = Op1.NET
• User-Name = IMSI_1
MME Topology Hiding
Gateway
DSRMME 1 MME 2
MME <> IMSI
Mapping
HSS
Tekelec Confidential56 I Tekelec. For What’s Next.
Current
Serving
MME
Previous
Serving
MME
IMSI
MME1 MME2 IMSI_1
HSS Topology Hiding
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HSS Topology Hiding
IMSI HSS
IMSI_1 HSS _1
1) Update-Location-Request
• Origin_Host = MME1
• Origin_Realm = Op2.NET
• Destination_Realm = Op1.NET
• User-Name = IMSI_1
Gateway
DSR MME 1
HSS 1 HSS 2
3) Update-Location-Answer
• Origin_Host = HSS1
• Origin_Realm = Op1.NET
• User-Name = IMSI_1
4) Update-Location-Answer
• Origin_Host = HSS_Public
• Origin_Realm = Op1.NET
• User-Name = IMSI_1
2) Update-Location-Request
• Origin_Host = MME1
• Origin_Realm = Op2.NET
• Destination_Realm = Op1.NET
• Destination_Host = HSS1
• User-Name = IMSI_1
DSR replaces HSS ID
with generic ID. The
mapping of IMSI <> HSS
is provisioned.
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HSS Topology Hiding
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HSS Topology Hiding
IMSI HSS
IMSI_1 HSS _1
Gateway
DSR MME 1
HSS 1 HSS 2
1) Purge-UE-Request
• Origin_Host = MME1• Origin_Realm =Op2.NET
• Destination Host = HSS1
• Destination Relam = Op1.NET
• User-Name = IMSI_1
1) Purge-UE-Request
• Origin_Host = MME1
• Origin_Realm =Op12NET
• Destination Host = HSS_Public
• Destination Relam = Op1.NET• User-Name = IMSI_1
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Roaming Steering
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g g
Tekelec Confidential59 I Tekelec. For What’s Next.
› Assumes operator has preferred roaming partner(s) for LTE roaming, such that it
is desirable for roaming subscribers to attach to the preferred visited network
whenever possible.› It may not be feasible to attach to a preferred network due to limited coverage, in
which case roaming on a non-preferred VPLMN can be allowed.
Roaming Area
Preferred Visited
PLMN
Non-
Preferred Visited
PLMN Allow LTE
roaming if sub is
in preferred
coverage
Prevent sub from
roaming into non-
preferred
networks
Example Flow - Preferred network
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p
Tekelec Confidential60 I Tekelec. For What’s Next.
Non-Preferred
Visited
PLMN
Rules
HSSHome PLMN
DSR
Preferred
VisitedPLMN
MME
MME
eNode B
eNode B
Roaming
Subscriber
Diameter: ULR
Trigger on
Registration
events with
PLMN ID
Event to SubscriberSpecific Rules DB
Using
Subscriber
Profile
PLMN ID
making
Roaming
Decision
DSR to
allow
registration
ULA to HSS
Example Flow - Not a Preferred network
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p
Tekelec Confidential61 I Tekelec. For What’s Next.
Non-Preferred
Visited
PLMN
Rules
HSSHome PLMN
DSR
Preferred
VisitedPLMN
MME
MME
eNode B
eNode B
Roaming
Subscriber
Diameter: ULR
Trigger on
Registration
events with
PLMN ID
Event to SubscriberSpecific Rules DB
Using
Subscriber
Profile
PLMN ID
making
Roaming
Decision
DSR to not
allow
registration
› Registration on non-preferred network can be allowed after configured # of failed attempts
› If there is other Roaming Agreement with the HPMN covering other Radio Access Technology(RAT) it could return a RAT_NOT_ALLOWED (5421) error to the MME
› If there is no Roaming Agreement between HPMN and VPMN it can sendROAMING_NOT_ALLOWED (5004)
USA Tier 1 Operator - MAP-Diameter IWF Use Case
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p
SGSN
DRA
GWDRA
SGSN
SGSN
Visited Net Home Net
HAR
S6d
S6d
Gr
S6d
LTE subs
3G subs
AT&T subs
roaming under
3G coverage
3G subs
SRP3G subs
LTE subs
IWF
LTE subs
LTE subs
› DSR will do address resolution on incoming S6d message and direct it to the HLR
for non-LTE capable subs, requiring Diam -> MAP conversion.
› Other use cases will arise.
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MAP-Diameter Interworking Function
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g
Example – Au thentic at ion request init iated by SGSN for UMTS/GERAN sub
DSRM-D IWF
vSGSN
1) MAP Send_Auth_Info
•Requesting node type = SGSN
SCCP
•CdPA=MGT
•CgPA=SGSN ID
AAAHSS
3) Auth-Info-Request
•Orig-Host=SGSN ID
•Req-UTRAN/GERAN -Auth-Info
4) Auth-Info-Answer
•Orig-Host=HSS ID
• Auth-Info=UTRAN vector
5) MAP Send_Auth_Info ack
• Auth set list=UTRAN vector
SCCP
•CdPA=SGSN ID
•CgPA=HSS ID
1. This covers the case where vSGSN doesn‟t know the HSS for the sub. Assumes the IMSI of the LTE-capable sub
is in a specific range that can be distinguished from non-LTE capable subs. Assumes Requesting node type =
MME/SGSN will not be used.
2. In the SS7 net, MGT or DSR ID can be used to GT route to DSR. It is assumed that IMSI is not sufficient.
3. DSR will be required to do HSS address resolution if necessary.
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2) MAP Send_Auth_Info
•Requesting node type = SGSN
SCCP
•CdPA=MGT, IMSI or DSR ID
•CgPA=SGSN ID
6) MAP Send_Auth_Info ack
• Auth set list=UTRAN vector
SCCP
•CdPA=SGSN ID
•CgPA=HSS ID
SS7
MAP-Diameter Interworking Function
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g
Example – Cancel location request init iated by HSS for UMTS/GERAN sub
DSR
M-D IWFvSGSN AAAHSS
1) Cancel-Location-Request
•Orig-Host=HSS ID
•Dest-Host=SGSN ID
6) Cancel-Location-Answer
•Orig-Host=SGSN ID
2) MAP Cancel_Location
SCCP
•CdPA=SGSN ID
•CgPA=HSS ID
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4) MAP Cancel_Location ack
SCCP
•CdPA=HSS ID
•CgPA=SGSN ID
SS7
3) MAP Cancel_Location
SCCP
•CdPA=SGSN ID•CgPA=HSS ID
5) MAP Cancel_Location ack
SCCP
•CdPA=HSS ID
•CgPA=SGSN ID
MAP-Diameter Interworking Function
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g
Example – Update Location initiated by SGSN
DSRM-D IWF
SGSN
Dialogue Continuation
UpdateGprsLocation
AAAHSS
ULR
ULA
UpdateGprsLocation ack
› “Dialogue Continuation” consists of the exchange of one or more InsertSubscriberData messages if
subscriber data is included in the ULA . If trace data is included in the ULA, the DSR sends an
ActivateTraceMode message to the SGSN.
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Policy Proxy 3G/LTE/IMS (Gx/Gxx/Rx/S9)
Use Cases
Policy Network Scaling
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Network-wide
PCRF Binding
Core Relay/Proxy
3G/LTE/IMS
(all interfaces)
Policy Proxy
3G/LTE/IMS
(Gx/Gxx/Rx/S9)
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PCRF
Topology Hiding
Scalability and
Connection
Management
Centralized
Routing and
Load Sharing
Network
VisibilityCentralized
Failover Models
TCP/SCTP
Interworking
Diameter
Variant
Mediation
Standard 3GPP Diameter Routing Agent (DRA)
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› Provides the standard 3GPP DRA
functionality
› Selects PCRF based on a load
balancing algorithm
› Same PCRF (MPE) within one
realm is selected for all user‟s
sessions› Acts by default as a Diameter proxy
with regards to Rx, Gx and Gxx
› Can act as DRA and/or Diameter
base proxy/relay agent based on
routing table configuration
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Gxx
GGSN/
PGW
Rx
Gx
PCRFHSGW/SGW
DSR(DRA)
P-CSCF
DSR Policy Scalability & Binding Overview
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› The DSR Policy Binding is a
feature capability of the DSR.
The DSR sits between the PCEFand the PCRFs in the network
› DSR Policy Binding Benefits:
Session correlation – The DSR
Policy Binding routes sessions for
the same UE to the same PCRF
Load balancing – The DSR Policy
Binding can balance transaction
load across PCRFs
Scalability – The DSR Policy
Binding allows the PCRFs toscale across sites by adding
hardware
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DSR
PCRF PCRF PCRF
PCEF
Site1
DSR
PCRF PCRF PCRF
Site2
DSR Policy Binding Message Flow
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1. The DSR Policy Binding receivesa message from a PCEF
2. The DSR Policy Binding makes arouting decision for the incomingmessage
› New UE – route to an PCRF basedon the load balancing algorithm
› Existing UE – route to the PCRF
that is already handling sessionsfor this UE
3. The DSR Policy Binding sends themessage to the appropriate PCRF
4. The PCRF processes themessage and sends the response
to the DSR Policy Binding
5. The DSR Policy Binding sends theresponse to the PCEF
1
32
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DSR
PCRF PCRF PCRF
PCEF
Site1
DSR
PCRF PCRF PCRF
Site2
4
5
Policy Binding Across a DSR Pair
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› Multiple DSRs serving one
Diameter realm act as one
logical DRA function ensuring
the same PCRF is selected forall user‟s sessions
› DRMA protocol: Diameter
Routing Management
Application – proprietary
Diameter application used for
inter-DRA communication
about load and topology
› Gateway DSRs supportroaming interfaces
› S9 policy/charging roaming
interface support to be added
when needed
Region 2
Region 1
DRMA
PCRF
P-CSCF
P-CSCF
IPX
PGW/
HSGW
PCRF
GatewayDSR
DSR
PGW/
HSGW
DSR
DRA
DRA
To/From Other
Networks
Policy Binding Across Multiple Pairs
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Region 2
Region 1› Subscriber Binding Repository
(SBR) added to each DRA to
retain binding information
› SBRs share binding information
with each other in real time
› Gateway DSR can be added to
the DRA pool to optimize S9
routing
DSR
DRA
PCRF
P-CSCF
P-CSCF
IPX
PGW/
HSGW
PGW/
HSGW
DSR
DRA
PCRF
DSR
DSR
GatewayDSR
Region 4
Region 3PCRF
PCRF
P-CSCF
PGW/
HSGW
P-CSCF
PGW/
HSGW
DRA
DRA
Subscriber Binding Repository
Replication
Diameter
Separate DRAs and Core DSRs
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Tekelec Confidential76 I Tekelec. For What’s Next.
Region 2
Region 1
DRMA
S6
› Core DSR nodes support S6a/d
interfaces to support internal
network scalability
› Gateway DSRs support
roaming interfaces
› Separate DSRs deployed to
serve as 3GPP Diameter
Routing Agents (DRA),
dedicated to PCRF binding
function for the network
› Multiple DSRs serving oneDiameter realm act as one
logical DRA function ensuring
the same PCRF is selected for
all user‟s sessions
› DRMA protocol: Diameter
Routing Management
Application – proprietary
Diameter application used for
inter-DRA communication
about load and topology
DSR
DRA
PCRF
P-CSCF
P-CSCF
IPX
PGW/
HSGW
MME
PGW/
HSGW
DSR
DRA
S6
PCRF MME
DSR
To/From Other
NetworksDSR
GatewayDSR
HSS
HSS
DSR Incorporates DRA Functionality
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Tekelec Confidential77 I Tekelec. For What’s Next.
› Core DSR nodes support DRA
function and S6a/d interfaces to
support internal network
scalability
› Gateway DSRs support
roaming interfaces
› Other charging and IMS
interfaces are also supported,
but not shown
› S9 policy/charging roaming
interface support to be addedwhen needed
Region 2
Region 1
DRMA
S6
PCRF
P-CSCF
P-CSCF
IPX
PGW/
HSGW
MME
S6
PCRF MME
GatewayDSR
DSR
PGW/
HSGW
DSR
DRA
DRA
To/From Other
Networks
HSS
HSS
UE attach – PCRF selected
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DSR NE
DSRGGSN PCRFRoaming
Agent
Gx CCR
SBR Response
Binding, looks for
existing bind
SBR Query
DSR Selects PCRFGx CCR
Gx CCA
Gx CCA
Gx CCR
Binding Persist Message
Binding found
SBR Response
SBR Query
Gx CCR
Gx CCA
Binding Update
Gx CCA
SBRPGW
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HSS Proxy LTE/IMS (S6/Cx/Dx/Sh/Dh)
Use Cases
HSS Access Network Scaling
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IMS HSS
Address
Resolution
LTE HSS Address
Resolution
Core Relay/Proxy
3G/LTE/IMS
(all interfaces)
HSS Proxy
LTE/IMS
(S6/Cx/Dx/Sh/Dh)
80 I Tekelec. For What’s Next. Tekelec Confidential
HSS
Topology Hiding
Scalability and
Connection
Management
Centralized
Routing and
Load Sharing
Network
VisibilityCentralized
Failover Models
TCP/SCTP
Interworking
Diameter
Variant
Mediation
Internal S6a Network without Agents
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Tekelec Confidential81 I Tekelec. For What’s Next.
HSS BE HSS BE HSS BE HSS BEMulti-HSS
› This shows the SCTP/Diametermesh created by just 6 MMEs and
4 HSSs, with 2 front ends per HSS
› Actual networks may have many
more MMEs and HSSs
Single HSS
› This shows a single HSS option
with all data for all subscribers in a
single backend
› Each MME could connect to just 2
front ends in order to partially
reduce the mesh, as shown
› However, HSS FE capacity mustbe hand-managed (e.g. where to
connect the next MME?, what
happens when traffic on one MME
grows disproportionately?, etc.)
HSS BE
HSS
FE
HSS
FE
HSS
FE
HSS
FE
HSS
FE
HSS
FE
HSS
FE
HSS
FE
HSS
FE
HSS
FE
HSS
FE
HSS
FE
HSS
FE
HSS
FE
MME MME MME MME MME MME
MME MME MME MME MME MME
Simplified S6a/S6d Network
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MME MME MME
Operator_N
HSS BE HSS BE HSS BE HSS BE
HSS
FE
HSS
FE
HSS
FE
HSS
FE
HSS
FE
HSS
FE
HSS
FE
HSS
FE
Operator_2
Operator_3Roaming Hub
Provider
MMEMME
MME
MMEMME
MME
MMEMME
MME
HSS
HSS
HSS
HSS
HSS
HSS
HSS
HSS
HSS
Diameter
Agent
Diameter
Agent
Diameter
Agent
Tekelec Confidential82 I Tekelec. For What’s Next.
Diameter
Agent
Interconnect to
Foreign Realms for
Roaming
Mapping of subscribers
to HSS, if needed.
Diameter Agent
significantly reduces
total number of
connections
Congestion Control
protects HSS
from overloadDiameter
Agent
USA Tier 1 Core Use Case - Regional S6a Architecture
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MME
Tekelec Confidential83 I Tekelec. For What’s Next.
Region 3
Operator_NOperator_1
Roaming Hub
DSR
DSRDSR
FE FE
FE FE
Region 4
Region 1
FE FE
Region 5
Region 2
FE FE
FE FE
DSR
DSR
MME MME MME MME MME MME
MME
MME
MME
DSR
DSR
MME
DSR Edge
Agent
DSR
HSS
HSS
HSS
HSS
HSS
HSS
USA Tier 1 Core Use Case
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84
SDM segment 2
SDM segment 1
DRA/SLF1 DRA/SLF2 DRA/SLF4
Colorado
SpringsCincinnati
Azusa Southlake Branchburg
DRA/SLF5 DRA/SLF6
DRA/SLF3
Full Mesh DRA network
SDM segment 3
DRA/SLF7 DRA/SLF8
Site 6 Site 7
Full Mesh DRA network
West Area Northeast Area
Midwest Area
DRA Network
South Area
› LTE network experienced rolling outage of HSS Front Ends (NSN-Apertio) triggered by single faulty MME.
› Adding DSR (DRA) to: 1) use message throttling to protect HSS FEs, and 2) use address resolution (SLF)
to split HSS data across new segments and introduce new HSS vendor(s).
HSS Topology Hiding
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IMSI HSS
IMSI_1 HSS _1
1) Update-Location-Request
• Origin_Host = MME1
• Origin_Realm = Op2.NET
• Destination_Realm = Op1.NET
• User-Name = IMSI_1
Gateway
DSR MME 1
HSS 1HSS 2
3) Update-Location-Answer
• Origin_Host = HSS1
• Origin_Realm = Op1.NET
• User-Name = IMSI_1
4) Update-Location-Answer
• Origin_Host = HSS_Public
• Origin_Realm = Op1.NET
• User-Name = IMSI_1
2) Update-Location-Request
• Origin_Host = MME1
• Origin_Realm = Op2.NET
• Destination_Realm = Op1.NET
• Destination_Host = HSS1
• User-Name = IMSI_1
DSR replaces HSS ID
with generic ID. The
mapping of IMSI <> HSS
is provisioned.
Tekelec Confidential85 I Tekelec. For What’s Next.
HSS Topology Hiding
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IMSI HSS
IMSI_1 HSS _1
Gateway
DSR MME 1
HSS 1 HSS 2
1) Purge-UE-Request
• Origin_Host = MME1• Origin_Realm =Op2.NET
• Destination Host = HSS1
• Destination Relam = Op1.NET
• User-Name = IMSI_1
1) Purge-UE-Request
• Origin_Host = MME1
• Origin_Realm =Op12NET
• Destination Host = HSS_Public
• Destination Relam = Op1.NET• User-Name = IMSI_1
Tekelec Confidential86 I Tekelec. For What’s Next.
HSS Resolution for LTE Mobility Management
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4. Update-Location-Answer › All fields same as msg3
3. Update-Location-Answer › Origin-Realm= epc.mnc015.mcc234.3gppnetwork.org
› Origin-Host= HSS2
Visited PMN
(MNC=123; MCC=567)
Home PMN
(MNC=15; MCC=234)
1. Update-Location-Request
› Destination-Realm= epc.mnc015.mcc234.3gppnetwork.org
› Origin-Host= MME1
› Origin-Realm= epc.mnc123.mcc567.3gppnetwork.org
› User-Name= 234150999999999
2. Update-Location-Request
› Destination-Host= HSS2
› All other fields same as msg1
vMME DSR
› Initial Update-Location message will contain pre-defined Destination-Realm constructed based on IMSI in the User-Name AVP, according to 3GPP TS 23.003
› DSR performs address resolution on message 1 and inserts Destination-Host associated with the IMSI, which is HSS2
in this example
› Subsequent messages are host routed, since the MME and HSS now know the identity of each other
HSS1
HSS3
HSS2
87 I Tekelec. For What’s Next. Tekelec Confidential
IMS Subscription Locator Function
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Invite
DSR
Scenario 1 – HSS Provides (redirect) SLF Function
Location-Info-Request (Public-ID)
Location-Info-Answer (Server Name= HSS2)
Location-Info-Request (Public-ID)
Location-Info-Answer (Destination Server)
Invite
Scenario 2 – DSR Provides (relay) SLF Function
DSR
Location-Info-Request (Public-ID)
Location-Info-Answer (Destination Server)
Location-Info-Request (Public-ID)
> Less messages
> Reduced delay
> Less HSS and CSCF
processing
S-CSCF
S-CSCF
HSS1 HSS2
HSS1 HSS2
88 I Tekelec. For What’s Next. Tekelec Confidential
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Charging Proxy 3G/LTE/IMS (Rf/Gy/Ro)
Use Cases
Charging Network Scaling
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Scalability and
Connection
Management
Centralized
Routing and
Load Sharing
Network
VisibilityCentralized
Failover Models
TCP/SCTP
Interworking
Diameter
Variant
Mediation
Core Relay/Proxy
3G/LTE/IMS
(all interfaces)
92 I Tekelec. For What’s Next. Tekelec Confidential
OCS/OFCS
Session-based
Routing
Charging Proxy
3G/LTE/IMS
(Rf/Gy/Ro)
OCS/OFCS
Topology Hiding
OCS/OFCS
Address
Resolution
Reference Model for 3G Online Charging
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OCS
Online Charging
Functions (OCF)
Tekelec Confidential93 I Tekelec. For What’s Next.
Recharging
Server
OSS – Post
Processing
SystemRo
Ro
Ro
Ro
Gy
Ge
(CAP)
Ga
Re
Rc Rr
Bo
Session
Based
Charging
Function
(SBCF)
Event
Based
ChargingFunction
(EBCF)Rating
Function
Charging
Gateway
Function
AccountBalance
Mgt
Function
MSC
GGSN
SIP AS
Service
Nodes
IMS
MRFC
IMS
Gtwy
Use Case – Offline/Online Charging Network Scaling
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Tekelec Confidential94 I Tekelec. For What’s Next.
Site 1
OFCF OFCF OFCF
PGW GGSN
OFCF OFCF OFCF. . .
SGW
OFCF
Site 2
OFCF OFCF OFCF
GGSN PGW
OFCF OFCF OFCF. . .
SGW
OFCF
DSRCharging Proxy
DSRCharging Proxy
Adding GW/CSCF/TAS
is transparent to OFCFs
Adding OFCFs is
transparent to
GW/CSCF/TAS
Significant reduction
in number of
connections
CSCF/
TAS
CSCF/
TAS
Common/centralized :
OFCF load-balancing Rf network intelligence
Rf troubleshooting
Topology hiding drives
the need for session
stateful routing
GzRf
3G Mobile GGSN - OCS
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Tekelec Confidential95 I Tekelec. For What’s Next.
SBCF/ABMF
SBCF/ABMF
SBCF/ABMF
8 SBCF‟s/Site
8 SBCF‟s/Site
8 SBCF‟s/Site
Enables future
separation of SBCF
and ABMF viaDiameter
interconnect
Addresses connection
limitations at GGSN
Eliminates need for
load balancers in front
of OCS SBCF/ABMF
SBCF/ABMF
SBCF/ABMF
GGSN
GGSN
GGSN
GGSN
GGSN
GGSN
GGSN
GGSN
GGSN
GGSN
GGSN
GGSN
GGSN
DSR
DSR
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Summary
Tekelec Confidential
Tekelec DSR - A Multi-application Diameter Agent
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Scalability and
Connection
Management
Centralized
Routing and
Load Sharing
Network
VisibilityCentralized
Failover Models
TCP/SCTP
Interworking
Diameter
Variant
Mediation
Network-wide
PCRF Binding
Roaming
Steering
MAP/Diameter
Interworking
HSS/MME/PCRF
Topology Hiding
IPsec
Core Relay/Proxy
3G/LTE/IMS
(all interfaces)
Policy Proxy
3G/LTE/IMS
(Gx/Gxx/Rx/S9)
Roaming Proxy
LTE/IMS
(S6/S9)
HSS Proxy
LTE/IMS
(S6/Cx/Dx/Sh/Dh)
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OCS/OFCS
Session-based
Routing
Charging Proxy
3G/LTE/IMS
(Rf/Gy/Ro)
OCS/OFCS
Topology HidingPCRF
Topology Hiding
HSSOCS/OFCS
PCRF
Agent
GGSN
PGWMME CSCF
Other
Networks
IMS HSS
Address
Resolution
LTE HSS Address
Resolution
HSS
Topology Hiding OCS/OFCS
Address
Resolution
Diameter Network with DSR
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Foreign LTE Domain
Home LTE/IMS Domain
Foreign GPRS Domain
ABMF RF
vSGSN
vS4-SGSN
vPCRF
Diameter
Agent
vMME
Diameter
Agent
IP-SM-GW
PGW
OCF
AF
OFCF
Ease of interworking› Mediation of Diameter variants
› SCTP-TCP interworking
› MAP-Diameter interworking
› IPv4-IPv6 interworking
Simple, secure network
interconnect
› Single point of interconnect› Access control
› Topology hiding
Improved network visibility› Generate reports and track KPIs
› Diagnose network problems
› Probeless monitoring
› Auto-config of perf. mgmt. system
› Capture encrytped messages
Simplified addressing› HSS address resolution and SLF
(subscriber mapping to HSS)› Maximizes HSS utilization and
allows for HSS arch flexibility
› Policy DRA for PCRF scalability
› On-line charging addr resolution
SS7
I/S-CSCF
PCRF
P-CSCFMME
EIR AAAHSS
Reduced network complexity› Adding endpoints requires
changes to agent only› Load balancing and
congestion/network mgmt.
handled by agent
DSR
HSS Res SBR
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Thank You
Tekelec Confidential
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Backup Slides
Tekelec Confidential
Acronyms
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Tekelec Confidential101 I Tekelec. For What’s Next.
ABMF Account Balance Mgmt. Function
AF Application Function
CSCF Call Session Control Function
DNS Domain Name System
DRA Diameter Routing Agent
EIR Equipment Identity Register
EPC Evolved Packet Core
GGSN Gateway GPRS Support Node
GRX GPRS Roaming eXchange
HSS Home Subscriber Server
IMC Inter-MP Communication
IMS IP Multimedia Subsystem
IPX IP Packet eXchange
IWF InterWorking Function
LTE Long Term Evolution
MME Mobility Management Entity
OCF Online Charging Function
OFCF Offline Charging Function
PCRF Policy and Charging Rules Function
PDN Packet Data Network
PGW PDN GateWay
RF Rating Function
SB Service Broker
SBCF Session Based Charging Function
SCTP Stream Control Transmission Protocol
SGSN Serving GPRS Support Node
SGW Serving GateWay
SLF Subscription Locator Function
SSR SIP Signaling Router
TCP Transmission Control Protocol
TLS Transport Layer Security
UE User Equipment
References
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› IETF 3588bis – Diameter Base Protocol
› 3GPP TS 29.272 – Mobility Management Entity (MME) and Serving GPRS Support Node (SGSN)
related interfaces based on Diameter protocol
› GSMA PRD IR.88 – “LTE Roaming Guidelines”
› 3GPP TS 23.003 – UMTS; Numbering, addressing and identification
› 3GPP TR 29.909 – Diameter-based protocols usage and recommendations in 3GPP
› 3GPP TS 33.210 – 3G Security; Network Domain Security; IP network layer security
› 3GPP TS 23.204 – Support of Short Message Service (SMS) over generic 3GPP Internet Protocol
(IP) access
› 3GPP TR 29.805 – InterWorking Function (IWF) between MAP based and Diameter based
interfaces
› 3GPP TS 29.305 – InterWorking Function (IWF) between MAP based and Diameter based
interfaces
› 3GPP TS 23.292 – IP Multimedia Subsystem (IMS) centralized services; Stage 2
› 3GPP TS 23.203 – Policy and charging control architecture
› 3GPP TS 29.109 - “Zh and Zn Interfaces based on the Diameter protocol”
top related