3. Scaling Diameter for LTE
• Introduction
• What is Diameter and Why it is important
• What it means for operators and vendors
• Market projections
• Diameter signaling controller requirements
• Role of Centralized Routing Databases
5. What is Diameter?
• Next generation signaling protocol, replacing
SS7
• Exchange subscriber profile data between
fundamental core network elements/systems:
– IMS
– EPC
– Billing systems
– Roaming exchanges
6. Why is Signaling & Diameter
Important?
• Since LTE has a relatively flat architecture, the
core network is more exposed to
signaling, than with 3G, which has an RNC.
• Network outages and/or poor performance
– Increases churn
– Destroys brands
7. Diameter Signaling Controllers
• New product category, encompassing
DEA, DRA, protocol translation, other
functions.
• More efficient, scalable, and reliable Diameter
networks
• Many dimensions for growth:
– Subscribers
– Voice and Data usage/sessions
– Dynamic billing and policy applications
– Roaming
8. Diameter Signaling Controllers
• Multi-billion dollar market opportunity
– New product category
– Major technology transition
– Continued strong organic growth in signaling
• High degree of vendor activity
– Very early days; Accelerating RFI/RFP activity
– Much more entry and consolidation to come
10. Diameter Underpins the
Monetization of LTE
Attachment/registration Mobility/tracking
Authentication & authorization Authentication & authorization
Data and voice sessions Roaming
QoS & charging
AAA, charging & QoS
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11. Diameter signaling pain points
Visited Home
service provider service provider
Interoperability
Overload &
downtime
Network
opacity
Network
complexity
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12. Outages are costly –
to top line and to brand
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13. Introducing
Diameter Signaling Controllers
All Diameter interfaces & applications
• Authentication Service provider
• Location/mobility HSS, OCS, PCR IPX/
• QoS F nodes roaming
• Charging hub
• LTE data and VoLTE roaming
Provides critical signaling controls
MME, PDN Visited
• Security service
GW, GGSN, CS
• Traffic & congestion control CF, AS provider
• Interoperability & mediation
• Routing & aggregation
• Reporting & analysis
• Fulfill key standards DSCs enable successful
• RFC 3588 Diameter agent transition to LTE & IMS
• 3GPP Diameter Routing Agent (DRA)
• Lowers total cost of ownership
• 3GPP Subscriber Location Function (SLF)
• GSMA Diameter Edge Agent (DEA) • Accelerates time to market
• Mitigates risk
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14. Where DSCs are needed:
Core and Edge
• Voice roaming
IPX
• Data roaming
MNO
Interconnect • Services
MNO
federation
Service provider
HSS, OCS, PCR
• Aggregation & F nodes
routing
• OCS proxy
Core
• HSS/AAA proxy
• PCRF proxy
MME, PDN
GW, GGSN, CS
CF, AS
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15. Key requirements
Universal Diameter interface support
Signaling security
Overload and congestion controls
Programmable L3-L5 interworking
Dynamic and scalable Diameter routing
Multi-vendor, end-to-end service
management & operations
Oct. 2012 Acme Packet | www.acmepacket.com
16. Scaling DSCs with Centralized
Routing Databases
Simplifies provisioning –
eliminates silos PSTN
Wholesale/
IPX
MNO
Highly scalable: 100s-1000s STP
Diameter
of millions of entries servers
Routing
DB
Support for
dynamic, complex routing Registries
decisions LCR LNP OSS
Diameter
clients
xCSCF
Integration with legacy Fixed Mobile
routing databases
DB query Diameter
Extensible – SIP, multi-
vendor, future applications
SIP
SOAP/XML
Oct. 2012 Acme Packet | www.acmepacket.com
17. Role of CRDB in NGN
Centralized Routing and
Database Services
18. Common Data – Multiple Applications
• SIP Services, DIAMETER services, TDM services
– All need access to shared/common routing data
• Common Routing Data
– Subscriber data
– Portability-data
– Code-range data
– MVNO data (Virgin Mobile)
– OTT data (GoogleVoice)
– Carrier-ENUM data (IMS endpoints)
– Routing policy data (Route-list for destinations)
• Internal routing
• Trusted interconnect partner routing
• Least cost interconnect routing
19. Common Data – Multiple Applications
Portability Data
Code-Range Data
Subscriber Assignment Data
Carrier-ENUM
Interconnect Trunk-Group Profiles
MVNO destinations
OTT destinations (Google Voice)
MULTIPLE Geographic destinations (LCR) MULTIPLE
DATA Local Routing Policy DATA
SOURCES L SOURCES
We ocal ery AP
b, p qu P, IN
File rovis ral
, S ion fer , MA
OA ing
P/X Re AIN
ML M,
E NU
CRDB
(ENUM, SIP, INAP, MAP, CAP, WIN, DIAMETER)
STP DRA S-CSCF
Connection Management Services
C4/C5 MSC SMS/MMS MGCF DEA pCSCF AS/TAS SBC
Network Edge Services
CONVERGED TDM & IMS NETWORK
20. Key Issues To Consider
• In-Switch Routing Model is Costly
– Provision common data into every switch
– Learn routing database model for every switch
– Staff routing experts for every switch
– Fix routing inconsistencies across multiple platforms
• CRDB Model is a Strategic Decision
– We’ve been living with cost of in-switch routing model for past
100-years. Obviously we can continue.
– Switching to a centralized model requires some strategy vision
to avoid the costs of the old model.
– Introduction of IMS-Core and DIAMETER services are
opportunity to switch to a centralized model
• Reduced network complexity (lower operating costs)
• Faster service deployment (faster revenue generation)
• Enhanced routing options (improved quality)
21. Additional Resources
Blog Post: The Next Generation Signaling
Core for LTE and IMS
White Paper: Scaling Diameter in LTE and
IMS
Oct. 2012 Acme Packet | www.acmepacket.com
Editor's Notes
There are more than 85 Diameter interfaces defined by the 3GPP and related standard bodies. These interfaces cover a range of network functions and is heavily used in IMS. With all LTE mobile networks, there are even more interfaces and transactionsDiameter signaling relates to network attachment and service delivery Data services – Internet, video, etc.VoIP and IMS servicesNetwork attachmentLocation updatesRoamingDiameter signaling relates toAuthenticationAuthorizationLocation/mobility trackingCharging/credit checksQoS/bandwidth-based admission controlNew attachmentsResets: UE crashes, battery swaps, etc.Power on after a few hours: plane trips, turn off for the nightRegister to LTE network and IMSTracking updates: moving aroundVoice and data sessions (bearer creation and teardown)Web surfing, email, videoVoLTE, RCS (IMS)QoS and charging interfacesRoaming: data and VoLTEAuthentication to visited networkAuthorization of servicesCharging and QoS policies
Customers are embarking on IP migration in the core. They are doing it to reduce costs (vs TDM) and enable new services and business models. But they leave behind some key aspects of the PSTN that result in challenges in the IP realm. Plus TEMs push solutions that are overly complex or costly. The chief challenges they face in this migration areLimited scalability – the volume of messages and Diameter transactions for authentication, mobility updates and each voice or data session can be huge. The processing load on Diameter elements can impact the ability to scale individual elements as well as the network at large. Complex provisioning and routing – given the number of elements, where they are located and how they must interconnect, the programming of route tables and the effective routing of messages in a network can be daunting to provision, maintain and change as the network grows. This complexity is costly in two areas: it results in an opex nightmare and slows down growth.Service availability is impacted by overload and network failure – the servers involved in processing various authentication, QoS or charging functions are not equipped to deal with spikes in volume; this can impact quality or availability of services. Elements as well as network data centers can also be taken out of serv iceLack of visibility – the ability to collect and correlate all messages with the number of elements and vendors and volume of transactions is formidable if not impossible; the information from these messages is critical for network planning, troubleshooting and daily operations.Multi-vendor interoperability – while Diameter is a standard, there are numerous interpretations of that standard as IMS and LTE has evolved and as more vendors enter the market. There are also differences in networks, such as transport protocol or IP version, that can cause incompatibility and transaction failures. Multi-vendor environments are long known for interoperability problems that add extra time or costs to an initial deployment and ongoing operations. The lack of interoperability hinders freedom of choice for service providers.
I-DSC is like an I-SBC connecting disparate retail and wholesale service providers together. This includes roaming and federation with OTT/MVNO providers. A C-DSC like a SRP, routing and aggregating Diameter traffic internal to a single operator. Core DSC applications extend to:Charging – online and offline (OCS proxy)QoS – bandwidth reservation and modification (PCRF proxy)Subscriber authentication and authorization (HSS proxy)Mobility and location updates (AAA proxy)HSS – Home Subscriber ServerPCRF – Policy Charging Rules Function
Routing of Diameter messages: flexible routing policies allow messages to be accepted or rejected depending upon source, destination, message type, and message value, thereby allowing the application of business logicDiameter signaling normalization: AVPs, and grouped AVPs can be normalized similar to SIP HMR, through the use of regular expression matching. AVPs can be removed, inserted, and modified. In addition, transport layer interworking between SCTP and TCP is performed automatically between ingress and egress interfaces, as is IPv4 to IPv6 conversion.Comprehensive security: Load limiting controls, including load balancing, and message rate limiting are extremely important to protect vulnerable Diameter elements. In addition, DDoS controls can be applied in order to stop out-of-control Diameter elements, such as new MME software loads that may exhibit bad (i.e. massively high rates of signaling) traffic under corner conditions.Comprehensive management: allows isolation and troubleshooting of Diameter issues within the network
Again, Benefits to Acme Packet Sales teamsDrive SBC, DSC, SR salesFills product gap and levels competitive landscape