02. dsr_overview july2012
DESCRIPTION
daTRANSCRIPT
Tekelec Confidential1 I Tekelec. For What’s Next.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.
DSR & Diameter Protocol Overview
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.
Tekelec Confidential2 I Tekelec. For What’s Next.
Signaling Protocol Evolution
� Diameter and SIP become the dominant signaling protocols
� SCTP “point-to-point” connections remain
Mobility and Subscriber Management
Application and Session Control
Tekelec Confidential3 I Tekelec. For What’s Next.
Comparing the SS7 and Diameter Protocol Stacks
� Diameter is an IP based protocol defined by IETF RFC 3588
� Diameter acts as an “envelope” for applications (= interfaces)
MAP
CAP
INAP
TCAP
SCCP
MTP
S6, s9, s13,
Gx, Gy)
Diameter
TCP/SCTP
IP/IPsec
� SS7 Entities vs. EPC Entities:
SS7
� Switching Transfer Point (STP)
� Home Location Register (HLR)
� Mobile Switching Center (MSC)
� Service Control Point (SCP)
EPC
� Diameter Relay Agent (DRA)
� Home Subscriber Server (HSS)
� Mobility Management Entity (MME)
� Policy & Charging Rules (PCRF)
Tekelec Confidential4 I Tekelec. For What’s Next.
Diameter Comparison to SS7
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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Diameter Fundamentals
� Defined by RFC 3588
� Designed as an improved version of Radius (AAA). Like RADIUS, aDiameter message, has a payload which is a collection of attributevalue pairs. It is peer-to-peer protocol.
� Diameter is defined in terms of a base protocol and a set ofapplications. This design allows the base protocol to be extendedto new applications. The base protocol provides basic mechanismsfor reliable transport, message delivery, and error handling.
� The base protocol must be used in conjunction with a Diameterapplication. Each application relies on the services of the baseprotocol.
� 3GPP has defined many new Diameter applications for use in IMS,LTE, and 3G.
� Requires security via TLS or IPsec, but these are not always usedin practice.
� Use Connection oriented Transport (TCP or SCTP based)
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Diameter Base Protocol and Applications
� Base Protocol Handles:
� Connectivity (Peers and Routing)
� Application Support (Application session management etc.)
� Data as collection of Attribute Value-pair (AVP)
� Applications
� Built on top of base protocol
� Purpose specific
� Each application must have an Application-ID (assigned by IANA)
- Example: 16777251 is S6a/S6d Interface Application
� Application-ID may also be used for message routing
S6
Applications
Other
Applications
Gx
Applications
Rx
Applications
Diameter Base Protocol
(RFC 3588)
Tekelec Confidential7 I Tekelec. For What’s Next.
Mobile Core Network Model
SGW
SGW
PGW
GGSN
OFCS
OCS
MME
MME
HSS/UDB
HSS/UDB PCRF
PCRF
IP Routing
Network
IP network perspective
Might look simple, but reality is more complex
Tekelec Confidential8 I Tekelec. For What’s Next.
Diameter is the New Signaling Language
MME
SGW
HSS
GGSN
PCRF
PGW
OCS
Mobile core elements communicate with each other
using Diameter signaling
IP
SCTP/TCP
Diameter
Tekelec Confidential9 I Tekelec. For What’s Next.
IP Routing
Network
Mobile Core Network Model
SGW
SGW
PGW
GGSN
OFCS
OCS
MME
MME
HSS/UDB
HSS/UDB PCRF
PCRF
Diameter connectivity perspective
Diameter Connection
IP
SCTP/TCP
Diameter
A Diameter connection is point-to-point
Tekelec Confidential10 I Tekelec. For What’s Next.
Mesh Network Topology
From a Diameter signaling perspective, the
previous mobile core was implemented as
a mesh network (fully or partially connected
network)
Diameter Signaling Issues
• Traffic Management
• Fault Management
• Route Management
• Scalability
• Interworking
• ))..
Mesh network topology does not support a
robust mobile core network
Unchecked
signaling traffic
can overwhelm
any node
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IP Layer
Diameter Layer
Creating a Diameter Network Layer
Application
Layer
Tekelec Confidential12 I Tekelec. For What’s Next.
Tekelec View of Diameter Signaling Core
SGW
SGW
PGW
GGSN
OFCS
OCS
MME
MME
HSS/UDB
HSS/UDB PCRF
PCRF
IP Routing
Network
Diameter connectivity perspective
DSR
DSR
Redundant and
highly available
Diameter Routing
Agent
Hierarchical
Diameter routing
topology over IP
packet routing
network
Tekelec Confidential13 I Tekelec. For What’s Next.
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
� New proposals to add Gy as a roaming interface for online charging
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
GGSN
Gx, Gxa, Gxb, Gxc, Rx
Diameter (PCRF) realm
DRADRA
Diameter (PCRF) realm
DRADRA
PLMN
MME MME MME
MME
PCRF
PCRF
HSSHSS
HSSHSS
13 I Tekelec. For What’s Next.
Proxy
Agent
Tekelec Confidential14 I Tekelec. For What’s Next.
Selected Diameter Interfaces in 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 / GGSN PCRF
Gy PGW / GGSN OCF
Gz PGW / GGSN 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
Tekelec Confidential15 I Tekelec. For What’s Next.
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 /
GGSN
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-GWAAAHSSHSS
SLF
Gr
Policy
SPR
Sh
Tekelec Confidential16 I Tekelec. For What’s Next.
The New Diameter Network
Tekelec Confidential17 I Tekelec. For What’s Next.
Scalability and
Connection
Management
Centralized
Routing and
Load Sharing
Network
ManagementCongestion
Control
TCP/SCTP
IPv4/IPv6
Interworking
Diameter
Variant
Mediation
Network-wide
PCRF Binding
Roaming
Steering
MAP/Diameter
Interworking
HSS/MME/PCRF
Topology Hiding
IPSec
Core & Routing
3G/LTE/IMS
Policy Proxy3G/LTE/IMS
(Gx/Gxx/Rx/S9)
Roaming ProxyLTE/IMS
(S6/S9)
Address
Resolution Proxy LTE/IMS (S6/Cx/Dx/Sh/Dh)
PCRF
Topology Hiding
DSR: a Multi-Solution Diameter Agent
IMS HSS
Address
Resolution
LTE HSS
Address
Resolution
HSS
Topology Hiding
Secure Access
/ Screening
Centralized Performance Management & Analytics: Diameter Intelligence Hub (DIH)Network
Intelligence
Network-wide
Session
Correlation
OCS/OFCS
Session-based
Routing
OCS/OFCS Proxy3G/LTE/IMS
(Gz/Rf/Gy/Ro)
OCS/OFCS
Topology Hiding
OCS/OFCS
Address
Resolution
Tekelec Confidential18 I Tekelec. For What’s Next.
Scalability and
Connection
Management
Network
ManagementCongestion
Control
TCP/SCTP
IPv4/IPv6
Interworking
Diameter
Variant
Mediation
Network-wide
PCRF Binding
Roaming
Steering
MAP/Diameter
Interworking
HSS/MME/PCRF
Topology Hiding
IPSec
Core & Routing
3G/LTE/IMS
Policy Proxy3G/LTE/IMS
(Gx/Gxx/Rx/S9)
Roaming ProxyLTE/IMS
(S6/S9)
Address
Resolution Proxy LTE/IMS (S6/Cx/Dx/Sh/Dh)
PCRF
Topology Hiding
DSR: a Multi-Solution Diameter Agent
IMS HSS
Address
Resolution
LTE HSS
Address
Resolution
HSS
Topology Hiding
Secure Access
/ Screening
Centralized Performance Management & Analytics: Diameter Intelligence Hub (DIH)Network
Intelligence
Network-wide
Session
Correlation
Centralized
Routing and
Load Sharing
OCS/OFCS
Session-based
Routing
OCS/OFCS Proxy3G/LTE/IMS
(Gz/Rf/Gy/Ro)
OCS/OFCS
Topology Hiding
OCS/OFCS
Address
Resolution
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1- Connection management
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
PCRF
PCRF
PCRF
PCRF
PCRF
PCRF
Tekelec Confidential20 I Tekelec. For What’s Next.
Connection management example
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
PCRF
PCRF
PCRF
PCRF
PCRF
PCRF
DSR
DSR
Tekelec Confidential21 I Tekelec. For What’s Next.
Scalability and
Connection
Management
Centralized
Routing and
Load Sharing
Network
ManagementCongestion
Control
TCP/SCTP
IPv4/IPv6
Interworking
Diameter
Variant
Mediation
Network-wide
PCRF Binding
Roaming
Steering
MAP/Diameter
Interworking
HSS/MME/PCRF
Topology Hiding
IPSec
Core & Routing
3G/LTE/IMS
Policy Proxy3G/LTE/IMS
(Gx/Gxx/Rx/S9)
Roaming ProxyLTE/IMS
(S6/S9)
Address
Resolution Proxy LTE/IMS (S6/Cx/Dx/Sh/Dh)
PCRF
Topology Hiding
DSR: a Multi-Solution Diameter Agent
IMS HSS
Address
Resolution
LTE HSS
Address
Resolution
HSS
Topology Hiding
Secure Access
/ Screening
Centralized Performance Management & Analytics: Diameter Intelligence Hub (DIH)Network
Intelligence
Network-wide
Session
Correlation
OCS/OFCS
Session-based
Routing
OCS/OFCS Proxy3G/LTE/IMS
(Gz/Rf/Gy/Ro)
OCS/OFCS
Topology Hiding
OCS/OFCS
Address
Resolution
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Request Routing Parameters
� Routing rules based on combinations of
� Destination-Realm (leading/trailing characters, exact match or wildcard)
� Destination-Host (leading/trailing characters, exact match, wildcard or presence/absence)
� Application-ID (exact match or wildcard).
� To facilitate screening, application invocation, and enhanced routing, additional data elements can be used:
� Command-Code (exact match or wildcard)
� Origin-Realm (leading/trailing characters, exact match or wildcard)
� Origin-Host (leading/trailing characters, exact match or wildcard)
� Rules prioritization enabled for Request matching multiple use defined rules
� Rule Action supported when this rule is invoked
� Route to Peer via Route List Table
� Route to Local DSR Application
- The message will be routed to the local DSR application identified by the rule’s Destination-Application-ID field
� Send Answer Response
- An Answer response will be sent with a configurable Result-Code and no further message processing will occur
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Routing & loadsharing example
Peer Routing Table (PRT)
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 careRoute to
PeerHUB_NW 1
opco2.com homeop.com Don’t care Don’t care Don’t careRoute to
PeerOPCO2_NW 1
homeop.com opco1.com 43 Don’t care Don’t careRoute to
PeerHSS1 1
homeop.com opco2.com 65 Don’t care Don’t careRoute to
PeerMME2 1
Don’t care Don’t care Don’t care Don’t care Don’t careSend Answer
“X”--- 99
Route List Table (RLT)
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
OPCO2_NW OPCO2_PEER1 1 100
OPCO2_NW OPCO2_PEER2 2 100
HHS1 HSS1_SRV1 1 100
MME1 MME1_SRV2 2 100
Active Route Group
Standby Route Group
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Routing & loadsharing example
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=4
Route-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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Scalability and
Connection
Management
Centralized
Routing and
Load Sharing
Network
ManagementCongestion
Control
TCP/SCTP
IPv4/IPv6
Interworking
Diameter
Variant
Mediation
Network-wide
PCRF Binding
Roaming
Steering
MAP/Diameter
Interworking
HSS/MME/PCRF
Topology Hiding
IPSec
Core & Routing
3G/LTE/IMS
Policy Proxy3G/LTE/IMS
(Gx/Gxx/Rx/S9)
Roaming ProxyLTE/IMS
(S6/S9)
Address
Resolution Proxy LTE/IMS (S6/Cx/Dx/Sh/Dh)
PCRF
Topology Hiding
DSR: a Multi-Solution Diameter Agent
IMS HSS
Address
Resolution
LTE HSS
Address
Resolution
HSS
Topology Hiding
Secure Access
/ Screening
Centralized Performance Management & Analytics: Diameter Intelligence Hub (DIH)Network
Intelligence
Network-wide
Session
Correlation
OCS/OFCS
Session-based
Routing
OCS/OFCS Proxy3G/LTE/IMS
(Gz/Rf/Gy/Ro)
OCS/OFCS
Topology Hiding
OCS/OFCS
Address
Resolution
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Per-Connection Ingress MPS Control
� This feature provides user-configurable Ingress MPS
control on a per-connection basis, allowing the user to
reserve and limit transaction capacity on each connection.
� This functionality ensures that each DSR peer connection
is provided a guaranteed transaction capacity while also
preventing DSR peers from flooding the network.
Connection Reserved
Ingress MPS
Maximum
Ingress MPS
MPS share
with other
connectionsConnection 1 100 500 400
Connection 2 0 5000 5000
Connection 3 500 500 0
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User-Configurable Message Priority
� Message priority profiles allow user-assignment of Priority to Request messages as they ingress the DSR
� Zero (0) is lowest priority
� Two (2) is highest priority
� Answer messages which ingress the DSR are assigned a priority of 3 and are NOT user-configurable
� Each profile supports user-assignment of priority to ingress Request messages based on message content using the strongest matching entry in the profile:
� Application-ID + Command-Code combination
� Application-ID
� All Request messages
� Example Ingress Request Priority Profile:
Application-ID Command-Code
Ingress Request
Priority
S6a AIR 0
S6a * 2
* * 1
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Egress Request Routing Based on Priority
� Request routing utilizes message priority and connection
congestion level in it’s connection selection criteria to avoid
sending priority x Requests to connections currently at
congestion-level x+1
Severity of
Congestion
Connection
Congestion
Level
Message
Priorities
Allowed Comment
Most
CongestedCL-3 3
Only allow Answers to be sent on
connection
More
CongestedCL-2 3, 2
Only allow Answers and Pri=2 Requests to
be sent on connection
Least
CongestedCL-1 3, 2, 1
Only allow Answers and Pri=2,1 Requests
to be sent on connection
Not
CongestedCL-0 All
All Requests and Answers can be sent on
connection
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Server A5
Client DSR
Server B
1 2
Remote Congestion Control
Phase 1
› Server B becomes congested and replies with DIAMETER_TOO_BUSY (Response 4)
› DSR marks Server B as “Congested” for a user-configurable time. During this time, DSR will not select Server B for new Requests
› Optionally, DSR can re-route Requests receiving DIAMETER_TOO_BUSY responses to an alternate Server (Request 5)
3Target
DSR
4 Congested
Server A3
Client DSR
1 2
Phase 2
› Server B begins responding slowly or the transport path to Server B becomes impaired, resulting in egress transport buffer/queue utilization on the DSR exceeding user-configurable thresholds
› DSR marks Server B as “Congested” until the buffers/queue depths abate to an acceptable level. During this time, DSR will not select Server B for new Requests.
Target
DSR
Server B
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Scalability and
Connection
Management
Centralized
Routing and
Load Sharing
Network
ManagementCongestion
Control
TCP/SCTP
IPv4/IPv6
Interworking
Diameter
Variant
Mediation
Network-wide
PCRF Binding
Roaming
Steering
MAP/Diameter
Interworking
HSS/MME/PCRF
Topology Hiding
IPSec
Core & Routing
3G/LTE/IMS
Policy Proxy3G/LTE/IMS
(Gx/Gxx/Rx/S9)
Roaming ProxyLTE/IMS
(S6/S9)
Address
Resolution Proxy LTE/IMS (S6/Cx/Dx/Sh/Dh)
PCRF
Topology Hiding
DSR: a Multi-Solution Diameter Agent
IMS HSS
Address
Resolution
LTE HSS
Address
Resolution
HSS
Topology Hiding
Secure Access
/ Screening
Centralized Performance Management & Analytics: Diameter Intelligence Hub (DIH)Network
Intelligence
Network-wide
Session
Correlation
OCS/OFCS
Session-based
Routing
OCS/OFCS Proxy3G/LTE/IMS
(Gz/Rf/Gy/Ro)
OCS/OFCS
Topology Hiding
OCS/OFCS
Address
Resolution
Tekelec Confidential31 I Tekelec. For What’s Next.
Scalability and
Connection
Management
Centralized
Routing and
Load Sharing
Network
ManagementCongestion
Control
TCP/SCTP
IPv4/IPv6
Interworking
Diameter
Variant
Mediation
Network-wide
PCRF Binding
Roaming
Steering
MAP/Diameter
Interworking
HSS/MME/PCRF
Topology Hiding
IPSec
Core & Routing
3G/LTE/IMS
Policy Proxy3G/LTE/IMS
(Gx/Gxx/Rx/S9)
Roaming ProxyLTE/IMS
(S6/S9)
Address
Resolution Proxy LTE/IMS (S6/Cx/Dx/Sh/Dh)
PCRF
Topology Hiding
DSR: a Multi-Solution Diameter Agent
IMS HSS
Address
Resolution
LTE HSS
Address
Resolution
HSS
Topology Hiding
Secure Access
/ Screening
Centralized Performance Management & Analytics: Diameter Intelligence Hub (DIH)Network
Intelligence
Network-wide
Session
Correlation
OCS/OFCS
Session-based
Routing
OCS/OFCS Proxy3G/LTE/IMS
(Gz/Rf/Gy/Ro)
OCS/OFCS
Topology Hiding
OCS/OFCS
Address
Resolution
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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, partial
value/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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Scalability and
Connection
Management
Centralized
Routing and
Load Sharing
Network
ManagementCongestion
Control
TCP/SCTP
IPv4/IPv6
Interworking
Diameter
Variant
Mediation
Network-wide
PCRF Binding
Roaming
Steering
MAP/Diameter
Interworking
HSS/MME/PCRF
Topology Hiding
IPSec
Core & Routing
3G/LTE/IMS
Policy Proxy3G/LTE/IMS
(Gx/Gxx/Rx/S9)
Roaming ProxyLTE/IMS
(S6/S9)
Address
Resolution Proxy LTE/IMS (S6/Cx/Dx/Sh/Dh)
PCRF
Topology Hiding
DSR: a Multi-Solution Diameter Agent
IMS HSS
Address
Resolution
LTE HSS
Address
Resolution
HSS
Topology Hiding
Secure Access
/ Screening
Centralized Performance Management & Analytics: Diameter Intelligence Hub (DIH)Network
Intelligence
Network-wide
Session
Correlation
OCS/OFCS
Session-based
Routing
OCS/OFCS Proxy3G/LTE/IMS
(Gz/Rf/Gy/Ro)
OCS/OFCS
Topology Hiding
OCS/OFCS
Address
Resolution
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Client Server
DSR
Agent
Agent
1
3
2
4
56
Client
DSR
Server
DSR DSR
12
4
5
Client Server
DSR
Agent
Agent
12
3
45
Timeout
Request Message Re-Routing
Alternate Routing on Answer
� Configurable per Result Code
� Response (3) may be DIAMETER_UNABLE_TO_DELIVER
Alternate routing on transport failure
� Connection failure occurs after message 3 has been sent
� T-bit set on re-routed message to warn of possible duplicate
Alternate routing on timeout
� No response received for message 2
� T-bit set on re-routed message to warn of possible duplicate
3
Target
DSR
Target
DSR
Target
DSR
Tekelec Confidential35 I Tekelec. For What’s Next.
Scalability and
Connection
Management
Centralized
Routing and
Load Sharing
Network
ManagementCongestion
Control
TCP/SCTP
IPv4/IPv6
Interworking
Diameter
Variant
Mediation
Network-wide
PCRF Binding
Roaming
Steering
MAP/Diameter
Interworking
HSS/MME/PCRF
Topology Hiding
IPSec
Core & Routing
3G/LTE/IMS
Policy Proxy3G/LTE/IMS
(Gx/Gxx/Rx/S9)
Roaming ProxyLTE/IMS
(S6/S9)
Address
Resolution Proxy LTE/IMS (S6/Cx/Dx/Sh/Dh)
PCRF
Topology Hiding
DSR: a Multi-Solution Diameter Agent
IMS HSS
Address
Resolution
LTE HSS
Address
Resolution
HSS
Topology Hiding
Secure Access
/ Screening
Centralized Performance Management & Analytics: Diameter Intelligence Hub (DIH)Network
Intelligence
Network-wide
Session
Correlation
OCS/OFCS
Session-based
Routing
OCS/OFCS Proxy3G/LTE/IMS
(Gz/Rf/Gy/Ro)
OCS/OFCS
Topology Hiding
OCS/OFCS
Address
Resolution
Tekelec Confidential36 I Tekelec. For What’s Next.
HSSHSS
S4 SGSNS4 SGSN
MMEMME
Diameter Hub for Performance & Intelligence
IMS
EIR
AAA
ePDG
SWm
S6d/a
Swx
S13
S6d
Gy
Gz
SW
x/a/m
Gy, Gz,
Gx
Gx, Rx,
S9
S6a
S13
Rx,Cx,
Dx,Sh,
S9
HSS
S4 SGSN
PDN Gw
PCRF
OCS
OFCS
IP networks
MME
HLR
vSGSN vPCRF
vMMEMAP
Integrated Monitoring into PIC:
› Probeless
� Direct enriched feed from DSR
› Security/Network Integrity
� DSR terminating IP-Sec tunnels from
partners’ networks.
Key Take Away:
LTE Performance Management Integrated In DSR Is A Key Differentiator
Tekelec Confidential37 I Tekelec. For What’s Next.
Network visibility - features
� Tracing
� Nodal transactions trace across DSR and 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
� Support for up to 5 simultaneous users
� Collection and Storage
� Create and store unique records for each desired transaction (PDUs, xDRs)
Tekelec Confidential38 I Tekelec. For What’s Next.
ProTrace Feature cont.
• Ladder diagram showing
continuous flow between
elements
• Entire screen can be
exported to a .zip file
containing xDRs, PDUs,
and the decode level detail
Tekelec Confidential39 I Tekelec. For What’s Next.
Tracing Feature Detail
• Single GUI for multi-
protocol, multi-network
call traces
• Powerful filtering
capabilities
Filter results
CDR
PDU
Decode
Tekelec Confidential40 I Tekelec. For What’s Next.
Scalability and
Connection
Management
Centralized
Routing and
Load Sharing
Network
ManagementCongestion
Control
TCP/SCTP
IPv4/IPv6
Interworking
Diameter
Variant
Mediation
Network-wide
PCRF Binding
Roaming
Steering
MAP/Diameter
Interworking
HSS/MME/PCRF
Topology Hiding
IPSec
Core & Routing
3G/LTE/IMS
Policy Proxy3G/LTE/IMS
(Gx/Gxx/Rx/S9)
Roaming ProxyLTE/IMS
(S6/S9)
Address
Resolution Proxy LTE/IMS (S6/Cx/Dx/Sh/Dh)
PCRF
Topology Hiding
DSR: a Multi-Solution Diameter Agent
IMS HSS
Address
Resolution
LTE HSS
Address
Resolution
HSS
Topology Hiding
Secure Access
/ Screening
Centralized Performance Management & Analytics: Diameter Intelligence Hub (DIH)Network
Intelligence
Network-wide
Session
Correlation
OCS/OFCS
Session-based
Routing
OCS/OFCS Proxy3G/LTE/IMS
(Gz/Rf/Gy/Ro)
OCS/OFCS
Topology Hiding
OCS/OFCS
Address
Resolution
Tekelec Confidential41 I Tekelec. For What’s Next.
Policy
DRA
Policy
DRA
Policy
DRA
Policy
DRA
Edge
Agent
GW GW
CSCF
Other
Nets
Replication/Messaging
TAS
CSCF
TAS
HSS FEHSS FE
HSS FEHSS FE
HSS FEHSS FE
HSS FEHSS FE
Gx, Rx, S9
Sh
Policy Network Scaling
Edge
Agent
PCRF
PCRF
PCRF
PCRF
PCRF
PCRF
PCRF
Even messages from remote
systems may need to be routed
to same PCRF.
Policy DRA enables PCRF
scalability by load sharing
to PCRFs
S9
Data replication and messaging
enable policy DRAs to act as a
single logical network.
and ensuring that
all messages for the same
subscriber are routed to the
same PCRF.
Tekelec Confidential42 I Tekelec. For What’s Next.
DSR Policy DRA Overview
� Supports a network of up to 14 (7 pairs) P-DRA DSR NEs. All P-DRAs in
the pool work together as a single logical P-DRA.
� Each pair of P-DRAs supports 120M active sessions.
� Up to 10 Gx sessions per subscriber.
� At most one real-time WAN traversal required to resolve a binding when
>1 pair of P-DRAs deployed (under non-error conditions).
� Performs topology hiding to hide the true identities of the PCRFs from
other elements in the network.
� Enabled for all roaming traffic or for configured list of destinations
� User configures virtual PCRF host ID
� Allows user to configure custom (Experimental-)Result-Codes to be
returned for various error scenarios.
Tekelec Confidential43 I Tekelec. For What’s Next.
Binding / Session Relationships
� A PCRF can host a large number of sessions
� All of the sessions for a subscriber are “bound” to the same PCRF
� A subscriber may have multiple simultaneous sessions
� P-DRA maintains the relationship between the subscriber and the PCRF
� This relationship is called a binding
Tekelec Confidential44 I Tekelec. For What’s Next.
Scalability and
Connection
Management
Centralized
Routing and
Load Sharing
Network
ManagementCongestion
Control
TCP/SCTP
IPv4/IPv6
Interworking
Diameter
Variant
Mediation
Network-wide
PCRF Binding
Roaming
Steering
MAP/Diameter
Interworking
HSS/MME/PCRF
Topology Hiding
IPSec
Core & Routing
3G/LTE/IMS
Policy Proxy3G/LTE/IMS
(Gx/Gxx/Rx/S9)
Roaming ProxyLTE/IMS
(S6/S9)
Address
Resolution Proxy LTE/IMS (S6/Cx/Dx/Sh/Dh)
OCS/OFCS
Session-based
Routing
OCS/OFCS Proxy3G/LTE/IMS
(Gz/Rf/Gy/Ro)
OCS/OFCS
Topology Hiding
PCRF
Topology Hiding
DSR: a Multi-Solution Diameter Agent
IMS HSS
Address
Resolution
LTE HSS
Address
Resolution
HSS
Topology Hiding OCS/OFCS
Address
Resolution
Secure Access
/ Screening
Centralized Performance Management & Analytics: Diameter Intelligence Hub (DIH)Network
Intelligence
Network-wide
Session
Correlation
Tekelec Confidential45 I Tekelec. For What’s Next.
4- Offline Charging Proxy – Vz W UC
Site 1
OFCF OFCF OFCF
PGW PGW
OFCF OFCF OFCF. . .
PGW. . .
OFCF
Site 2
OFCF OFCF OFCF
PGW PGW
OFCF OFCF OFCF. . .
PGW. . .
OFCF
DSRDSR
Adding GW/CSCF/TAS
is transparent to OFCFs
Adding OFCFs is
transparent to
PGW/CSCF/TAS
Significant reduction
in number of
connections
CSCF/
TAS
CSCF/
TAS
Rf
Common/centralized :
� OFCF load-balancing
� Rf network intelligence
� Rf troubleshooting
Topology hiding drives
the need for session
stateful routing
Tekelec Confidential46 I Tekelec. For What’s Next.
Secure
interconnection for
M2M services
Grow
RevenuesEliminate
Signaling
Storms
The Value of Diameter Routing
Load
balancing
� Proxies for: Over-the-Top/Cloud/M2M Services, LTE/3G Roaming,
Policy, Charging, Home Subscriber Server
Congestion and
traffic management
Scale Diameter
transactions
Interworking and
interoperability
Network visibility
Steer
roamers to
preferred
partners
Reduce
revenue
leakage
, Secure
interconnection
for Cloud
services
Secure
interconnection
for OTT Apps
Tekelec Confidential47 I Tekelec. For What’s Next.
Diameter Market Leadership
Major Policy + SDM Wins
55 Policy customers/43 Tier 1s
46 SDM customers/27 HSS/SPR
300 Million SDM Subs
Expanding Global, Multi-Property
Policy Deployments
19 DSR Customer Wins and Counting – US/Canada/Europe/Asia/CALA
“Tekelec’s Policy Server is at or near the top of the competitive landscape”
“Tekelec is the front runner in the
Diameter signaling control market.”
“The leader in DSC today is Tekelec withJ
roughly 80% market share”
Tekelec has 75-85% market share of
the exploding Diameter Signaling
Controller market
Tekelec Named #1 Independent Policy
Market Leader for Third Consecutive Year
Tekelec Confidential48 I Tekelec. For What’s Next.
The reasons to implement a DSR
� Complexity and scalability: Difficult to manage large number of SCTP/Diameter
connections without a DSR.
� Congestion Control - Signaling storm will also happen to small networks
� e.g. prevent a failed MME to flood HSS with requests
� IP Router does not perform routing at Diameter Layer:
� Cannot perform effective load balancing
� Cannot perform congestion control
� Diameter Protocol Mediation - devices from different vendors do not always work well
together.
� DSR provides additional features:
� Address resolution function to map subscribers to HSSs, for LTE mobility management
� PCRF load-sharing and policy binding
� OCS load sharing and session binding
� Single point of interconnect to other LTE networks:
� Simplify routing and provide security (IPsec, Topology Hiding)
� Need Diameter Mediation for LTE Roaming
� Visibility of critical Diameter interfaces (Diameter Protocol tracing)
Tekelec Confidential49 I Tekelec. For What’s Next.
Customer reference
Operator Size
(subs)
Deployme
nt Target
# Nodes MPS
/Node
Connec-
tions/Node
Use Case
Tier 1 NA Carrier “A” 95.5 M 2012 10 20k 200 Core LTE HSS Proxy
Tier 1 NA Carrier “A” 95.5 M 2012 10 100k 2000 Core IMS VoIP Routing
Tier 1 NA Carrier “A” 95.5 M 2012 10 200k 2000 Policy AS DRA
Verizon Wireless 94 M 2011 2 3000 50 Roaming Proxy
Verizon Wireless 94 M 2011 2 160k 8000 OFCS Binding
Verizon Wireless 94 M 2011 6 40k 500 Core LTE/IMS HSS Proxy
Verizon Wireless 94 M 2011 PCRF DRA/MRA
MetroPCS 8 M 2011 2 100 10 Core Proxy
NA Hub Provider “S” n/a 2011 2 40k 10 Hub Roaming Proxy
NA Hub Provider “T” n/a 2011 2 1000 10 Hub Roaming Proxy
Tier 1 APAC Carrier “O” >5M 2012 2 n/a Core Relay/Proxy
Tekelec Confidential50 I Tekelec. For What’s Next.
Customer reference - lab
Operator Size
(subs)
Deployme
nt Target
# Nodes MPS
/Node
Connec-
tions/Node
Use Case
Tier 1 APAC Carrier “C” 584 M 2012 Lab 25k 50 LTE Routing Trial
Tier 1 NA Carrier “S” 49.9 M 2012 Lab 100 10 LTE Routing Trial
TC n/a 2011 Lab 10k 100 Hub Roaming Proxy
Tier 1 EMEA Carrier “1” >10M 2011 Lab ~200 Core Relay/Proxy
Tier 1 India Carrier “R” >10M 2012 Lab ~15K Core Relay/Proxy,
LTE/IMS HSS Proxy
Tier 1 CALA Carrier “T” >10M 2012 Lab n/a Core Relay/Proxy. Policy
Proxy
Tekelec Confidential51 I Tekelec. For What’s Next.
Tekelec DSR Key Takeaways
� Most Tier-1 customer deployment references
� Most patents and intellectual properties awarded in the
area of Diameter signaling and routing
� Advanced features set built into our DSR products
� Congestion Control
� GUI based Mediation engine
� Integrated Diameter protocol analysis tool
� Troubleshooting & Protocol tracing
� Tekelec reputation as a signaling leader in SS7 and
Diameter signaling networks
Tekelec Confidential52 I Tekelec. For What’s Next.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.
Thank You !
Tekelec Confidential53 I Tekelec. For What’s Next.
Acronyms
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