Peering Architecture
IETF-63 VoIP Peering BOF
Sohel Khan, Sprint, TR&D
August 4, 2005
Copyright © Sprint 2005. All rights reserved.
Peering Requirement
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Security and Policy
Integrity
Efficiency
Reliability
Scalability
Harmonious Interoperability
Regulatory
Accounting
Sohel Khan, Sprint--TR&D.
Copyright © Sprint 2005.
2
The major Issue
• State and Cost
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Where the state be deployed?
What kinds of state should the network have?
What are the impacts of state?
What is the cost of media forwarding circuitry?
What is the cost of signaling infrastructure?
Security features
SIP optimization
Transcoding
Regulatory implementation
We believe that above depends on
the way you deploy peering elements (PEs)
Sohel Khan, Sprint--TR&D.
Copyright © Sprint 2005.
3
Conceptual Deployment Scenarios
We illustrate four scenarios
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Composed
Semi-Composed
Centralized (Non-IMS, IMS NNI, IMS UNI)
Distributed
• Our objective is to generate discussion in
IETF community
• draft-sohel-sipping-s-bc-concept-arch-00.txt
• PTSC-SAC-2005-213, ATIS-PTSC, June, 2005
Sohel Khan, Sprint--TR&D.
Copyright © Sprint 2005.
4
Reference Diagram
IP Phone
SF
Provider MF
A
RF
Wireless
OF
SF
MF
RF
Wireless
Provider
B
OF
IP Phone
SS7
MG
MG
SF: Signaling Function
MF: Media Function
RF: Routing Function
OF: O&M Function
PSTN
SS7
PSTN
Ref.
Functions
SF
SIP Proxy, B2BUA, Session Admission Control (SAC), SIP Interoperability, SIP DoS protection,
SIP Topology Hiding (THIG), and SIP security, privacy and encryption
MF
VPN mediation, traffic engineering, policy enforcement, rate shaping, bandwith broker,
bandwidth theft protection, data integrity, transcoding, RTP translator, Network Address
Translation (NAT), and media security, privacy and encryption.
RF
Routing protocol harmonization
OF
CALEA implementation; accounting, billing and operational data mediation
Sohel Khan, Sprint--TR&D.
Copyright © Sprint 2005.
5
ETSI TISPAN NGN Functional Architecture and Peering Elements
Rr/Ro
IMS functions
ETSI TISPAN extensions
Sh
HSS
AS
Charging Function
Dh
ISC
Cx
Mw
Mw
S-CSCF
Mr
SF
Rf/Ro
Dx
Ia
I-CSCF
Mi
IWF
Ib
Mi
Mw/Mk/Mm
BGCF
Mg
UE
Gm
Gq
RACS
PDF
NASS
Mn
Mp
SGF
Ie
Id
SGW
PSTN/ISDN
PSTN
If
MGCF
MRFC
Ic
SEG
Mj
P-CSCF
P-
IBCF
Other IP Networks
Mw
Cx
Other IP networks
SF
SLF
MF + RF
A-BGF
MRFP
T-MGF
MGW
I-BGF
IP transport (access and core)
OF Functions not shown
Sohel Khan, Sprint--TR&D.
Copyright © Sprint 2005.
MF + RF
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Conceptual Architecture Composed PE
CSCF
IP Phone
Proxy
SBC
SBC
Proxy
Wireless
CSCF
MGCF
MGCF
SBC
SBC
3rd
SS7
Wireless
IP Phone
Party IP Network
MG
MG
SS7
PSTN
SF
PSTN
MF
MG: Media Gateway
MGC: Media Gateway Controller
LD: Long Distance
RF
OF
Composed architecture integrates
Control, Bearer, and Routing planes
in same device.
Risk: N2 connectivity, cost, bottleneck, hot-potato route
Bearer (RTP/IP)
Signal (SIP)
Session Border Controller (SBC)
Sohel Khan, Sprint--TR&D.
Copyright © Sprint 2005.
7
Conceptual Architecture: Semi-Composed PE
IP Phone
SF
Proxy
CSCF
SF
Wireless
Proxy
CSCF
MGCF
SF
Wireless
SF
MGCF
IP Phone
SS7
3rd
MG
Party IP Network
MG
MF + RF
SS7
PSTN
PSTN
SF
Edge-Proxy/
CSCF, PDF,…
Security + Policy
H.248/SIP
MG: Media Gateway
MGC: Media Gateway Controller
LD: Long Distance
Bearer (RTP/IP)
Signal (SIP)
MF
Media Relay/E-LSR
Security + Policy
Routing
MPLS Switch/Media Relay
RF
This architecture splits the Control and
Bearer + Routing planes in separate devices.
This is a one-to-one model
Media and Signal do need to flow the
same network.
Sohel Khan, Sprint--TR&D.
OF functions distributed across entitiesCopyright © Sprint 2005.
8
Conceptual Architecture: Centralized (Non-IMS) NNI PE
Media Relay/MPLS Switch
Sprint
VoIP
Other
VoIP
IP Phone
Wireless
SF MGCF
Wireless
SF MGCF
ENUM
ENUM
IP Phone
3rd
Party IP Network
MG
SS7
MG
SS7
PSTN
PSTN
PSTN
PSTN
SF
MGCF+SF
Security + Policy
MF
MF
RF
RF
Media Relay/E-LSR
Security + Policy
Routing
Media Relay/E-LSR
Security + Policy
Routing
Control plane of SBC integrates with MGC
functions, Bearer + Routing planes integrate
with edge routers. One-to-many model
Sohel Khan, Sprint--TR&D.
OF functions distributed across entities Copyright © Sprint 2005.
9
Conceptual Architecture: Centralized (IMS) NNI PE
Media Relay/MPLS Switch
Sprint
VoIP
Other
VoIP
IP Phone
Wireless
CSCF BGCF SF
SF BGCF CSCF
ENUM
Wireless
ENUM
IP Phone
3rd
Party IP Network
MG
SS7
MG
SS7
PSTN
PSTN
PSTN
PSTN
SF
IBCF+I-CSCF+ SF
Security + Policy
MF
MF
RF
RF
Media Relay/E-LSR
Security + Policy
Routing
Media Relay/E-LSR
Security + Policy
Routing
Control plane of SBC integrates with CSCF,
Bearer + Routing planes integrate with edge
routers. One-to-many model
Sohel Khan, Sprint--TR&D.
OF functions distributed across entities Copyright © Sprint 2005.
10
Conceptual Architecture: Centralized (IMS) UNI PE
I-CSCF
S-CSCF
PDF + P-CSCF
SF
MF + RF
A-BGF
PCS tower
PCS tower
PCS tower
OF functions distributed across entities
Sohel Khan, Sprint--TR&D.
Copyright © Sprint 2005.
11
Conceptual Architecture: Distributed NNI PE
Media Relay/MPLS Switch
Sprint
VoIP
Other
VoIP
IP Phone
Wireless
SF+ CSCF+ MGCF
SF+ CSCF+ MGCF
ENUM
Wireless
ENUM
IP Phone
3rd
SS7
Party IP Network
MG
MG
SF+RF+MF RF+MF
SS7
PSTN
PSTN
PSTN
PSTN
SF+ CSCF + MGCF
Security + Policy
SF
SF+RF+MF
RF+MF
SIP aware
Firewall
Media Relay/E-LSR
Security + Policy
Routing
This model distributes Control, Bearer, and
Routing plane functions in different devices
across the network
Sohel Khan, Sprint--TR&D.
OF functions distributed across entities Copyright © Sprint 2005.
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