Dr. Helmut Schink
VP Network Technology Strategy
Siemens Information and Communication Networks
1
Voice Transport: Circuit- vs. Packet-Switched
Switch
SS7
TDM
PSTN/PLMN
SS7
Switch
PSTN/PLMN
8000 samples/s
8000 samples/s
POTS
ISDN-BA
ISDN-PRA
V5.x
SS7
IP or ATM Core
Switch
PSTN/PLMN
2
Basic Elements for IP Telephony
TDM Switch
Management System
TDM network
3rd-party applications/back-end
Voice
Gatekeeper
Call Control &
Applications
Multiservice
access
Radius server
Media
gateway
Data
ATM/IP network
3
Interconnection
Gatekeeper
Call feature server
media gateway controller
signaling gateway
open service platform
Management station
Radius server
Media
gateway
TDM Network
Applications
IP Network
n Media gateways
interconnect TDM and IP
networks and provide the
conversion of media
streams.
n Service convergence is
realized with centralized
feature and signaling
interworking between
networks.
n Media-control is
decoupled from media
transport, giving a carrier
the choice regarding the
underlying transport
technology.
4
Generic Network Structure
mobility
Value added
services, IN
Call processing
B2B
B2C
network
services
portals
directories
Applications
IP network:
managed or public?? Optical backbone
legacy
voice
xD
SL
M
WD
SDH
Mediation
gateway
le
b
ca
SM
G
Broadband
access
AN
WL
ISDN
PO
TS
UM
TS
wireless
access
PM
P
edge router
5
Current IP Network Architecture
Network layer = IP
QoS
QoS of
of the
the application
application (i.e.
(i.e.
voice)
voice) will
will be
be affected
affected
(virtual) permanent connection
Transport layer =
FR, ATM,
SDH, WDM
Quality-/Class-of-Service
Growth-Challenges
n
n
n
n
n
n
n
n
Traffic engineering / traffic management
Differentiating services
SLA support / monitoring
Reliability
Number of neighbors (PVCs)
Size of routing tables
Throughput
Router hop-count
6
Internet: principle configuration
Peering
Peering Points:
Points:
MAE:
MAE: Metropolitan
Metropolitan Area
Area Exchange
Exchange
NAP:
NAP: National
National Access
Access Point
Point
CIX:
Commercial
Inter-Exchange
CIX: Commercial Inter-Exchange
The Internet
(peering points)
Billing/Settlement
Billing/Settlement of
of the
the
service
service needs
needs to
to be
be done
done
separately
separately
Global ISPs
MCI, Sprint, UUNet
EBONE
T-Online
Large
Carriers
Regional ISPs
Local ISPs
Regional ISPs
Local ISPs
Carrier network
Carrier network
7
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