3. IP comms network control
– complex & challenging
All-IP networks are built differently
SIP - control communication sessions
- voice, video, IM, presence, … LTE
&
IMS
Diameter - exchange 2G/3G
&
PSTN
subscriber authentication, SIP
authorization, location; SS7
session QoS & charging
Diameter
Exploding signaling traffic
Moving beyond voice
- UC, RCS messaging, collaboration
Extreme mobile data
Mobile device proliferation
– smartphones, tablets, M2M
Increased mobility and roaming
4. The Next Gen Signaling Core
Diameter SIP core
servers I/S-CSCF
HSS, OCS, PCRF
Roaming IP Peering
partners
Routing
I-SBC partners
IPX carriers
IP
DSC Wholesale transit
Routing
TDM
Roaming hubs MGCF IPX carriers
Diameter IMS NGN
clients edge edge
MME, PDN GW, SBC, C5 SS,
GGSN, CSCF, AS P-CSCF S-MSC
Internet LTE 3G DSL/Cable/
FTTx
4
5. Diameter roles in LTE & IMS
Attachment/registration Mobility
Authentication & Authentication &
authorization location updates
Data and voice sessions Roaming
QoS & charging AAA, charging & QoS
6. Diameter Interfaces in LTE and IMS
IMS Sh
Ro Cx Diameter Pain Points
Rf e2 Scalability and
Complexity
Rx
EPC S9 Interoperability
Gy/
Gz Other Challenges
Gx S6a service Overload and
Gx S6a
providers
Congestion
Security
S6d
6
7. Messy mesh of signaling –
unscalable, unsecure, unmanagable
Visited
Home
service
provider
service
provider
8. Introducing
Diameter Signaling Controllers
All Diameter interfaces & applications
• Authentication Service provider
• Location/mobility HSS, OCS, IPX/
• QoS PCRF nodes roaming
• Charging hub
• LTE data and VoLTE roaming
Provides critical signaling controls
MME, PDN Visited
• Security service
GW, GGSN,
• Traffic & congestion control CSCF, 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
Oct. 2012 Acme Packet | www.acmepacket.com
9. DSCs ensure service availability &
reliability, lower TCO
Visited Home
service provider Multivendor service provider
interoperability
Simplified
routing & config
Congestion &
overload control
Security
Signaling
performance
scalability
Service
visibility
10. Diameter signaling controllers are
intermediaries in Diameter transactions
Clients
Agent
Servers
Request
Request
Response
Clients Agents Servers
request info or send parse, manipulate store info, process
updated info to and route Diameter or respond to
Diameter servers messages as they requests from
flow from client to clients
server and server
to client
11. Diameter Signaling Controllers are
different from STPs
Diameter lacks congestion management and
resource allocation provided by SS7
– Similar to the ISUP to SIP paradigm shift
– Same challenges in Signaling Control for Diameter
and SIP
– Routing logic MUST be based on flexible criteria
Security for Diameter signaling is key
– Hardware based encryption and Access Control
– DoS protection
– rate limiting and Overload Control
Diameter Signaling Adaptations will be required
– Diameter AVP manipulations to normalize vendor
implementations
– IP and transport layer interworking
Diameter is an IP Signaling Protocol
11
Acme Packet confidential
12. SS7 vs. Diameter networks
MAP S6, S9, S13, e.g.
Gx,Gy,Gz
CAP Cx,Dx,Sh,Dh
subscrip,on
ID
INAP Rx,Ro,Rf,
Des,na,on
TCAP Diameter realm
SCCP Global
Title
SCTP
MTP OPC/DPC
IP
different layers carry address information
02/03/12 Acme Packet | Product Overview 12
13. Two Types of DSCs:
Core and Edge OTT/
Cloud
• Voice roaming IPX
• Data roaming MNO
Edge • Services
federation
MNO
Service provider
HSS, OCS, PCRF
• Aggregation & nodes
routing
Core • OCS proxy
• HSS/AAA proxy
• PCRF proxy
MME, PDN GW,
GGSN, CSCF, AS
13
14. Core Diameter routing solution
Core DSC requirements
Universal Diameter agent Central node for
Online charging (OCS) – Gy, Rf, Ro all Diameter signaling
QoS / policy (PCRF) – Gx, Rx
Server
Subscriber profile/AAA (HSS) – nodes
S6a, S6b, S6d, Swm
3GPP DRA and SLF functions
Connection aggregation, routing
& load balancing Client
Overload control nodes
Layer 3-5 interworking
Reporting and analysis
Benefits
Streamlined and scalable network 3G LTE
Improved network resiliency
Lower total cost of ownership
Faster time to market
Enhanced visibility and manageability
14
15. VoLTE and Data Roaming Solution
Comprehensive SIP and Diameter control across roaming ecosystem
Edge DSC – DRA and GSMA DEA functions: S6a & S9 interfaces
Access SBC – Visited P-CSCF
Interconnect SBC – I-BCF/TrGW and IPX Proxy
Potects Diameter and SIP borders – service availability
Maximize service reach – end-to-end interworking
Cost effective scalability – lower TCO
Visited Home
IPX
LTE SIP Data LTE
RTP Diameter
15
17. Security requirements
Challenge:
Ensure service availability for LTE and IMS
services that depend upon Diameter signaling
Requirements:
DoS protection
Avoid resource starvation
Prevent Diameter overloads
Diameter fuzzing protection
Topology hiding
Block IMSI ranges
Encryption of Diameter messages
18. Traffic Control requirements
Challenges:
Maximize utilization of network resources
Monitor network element availability and
perform workarounds when necessary
Requirements:
Transaction rate policing by agent
or group
Monitor upstream and downstream agent
availability
Diameter load balancing to external nodes
Fine grained policy-based routing and
rejection
Agent failure detection and route-around
Active-Active redundancy
19. Routing requirements
Challenge:
Complexity of Diameter routing while scaling network
Route to hundreds of internal and external elements
Requirements:
IMSI to HSS resolution
Route to correct home MNO
Preferred network selection
PCRF binding
Internal diameter aggregation
Flexible routing
Message rejection /forwarding
20. Interoperability requirements
Challenges
Diameter interoperability in multi-vendor
environments
Diameter implementations may not have
compatible AVPs
Multiple IP networks for transport with
differing address schemes
Diameter implementation running over
different transport protocols
Requirements
Diameter signaling normalization
Transport layer interworking
IP address interworking
Broad standards compliance
21. Conclusions
Diameter & SIP signaling underpin all services
in LTE and IMS
Assuring interoperability and service availability/reliability
as network scales are signaling pain points
Diameter signaling controllers addresses these challenges
for multiple use cases – core, interconnect, federated
services
22. Thank You
Learn more at
www.acmepacket.com/diameter