Transcript Document 7324453

Connecting Your SIP-Based Hosted
Contact Center to the Rest of the World
Brough Turner, SVP & CTO, NMS Communications
Communications in Transition
• New services on IP-based platforms
– SIP signaling
– G.711 “voice” over RTP
• Lower cost
• Easier development
• Faster time-to-market
• Web & IT convergence
Dramatic simplification over PSTN platforms
3
IP-based Services & Systems
• IP call centers, IP PBXs
• Self-service customer voice portals
Financial
Services
4
Travel and
Leisure
Telecom /
Utilities
• Account
balances
• Reservation
confirmation
• Mortgage
refinance
screening
• Theater &
Hotel booking
• Service
activation /
repair
• Bank location
• Prepaid
calling card
front end
• Insurance
claim status
• Service
outage info
Government
• Tax info
• Postal
information
Retail
• Account
balances
• Catalog
requests
• Unemployment
check status
• Store locator
• International
traveler
information
• Order tracking
• RMA request &
status chk
Modern Self Service Platform
Follows 3-tier IT architecture
• Database engine
• Business logic
– May use application server (dynamic VoiceXML)
• Presentation
– Web servers
– Media processor (VoiceXML browser)
5
Example Avaya Voice Portal
6
VoIP Adoption
Skype
registrations:
171M
VoIP
subscribers:
38M
Fixed PSTN: 1.2B
7
Mobile PSTN: 2.7B
Connecting to PSTN
• VoIP access to PSTN readily available from major
inter-exchange carriers
– Send VoIP traffic almost anywhere in the world
– Receive PSTN traffic from anywhere in US
Speech
Resources
IP Telephony
IXC Gateway
http://voiceXML…
MRCP
Databases,
Web Services,
Persistent
Business logic
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SIP
Web Server
VoiceXML Server
RTP
VoIP
IXC
PSTN
Not so easy in Rest of World
• Problem: inbound traffic, PSTN to VoIP
• Advertise PSTN numbers, receive incoming
traffic over IP
• Available as a service in US, parts of the EU,
HK, Japan, Australia and Brazil
– Voxbone offering more countries
Expensive or unobtainable
in most of the rest of the world
9
Nominal Solution
• Provide PSTN gateway with IP-based application
Speech
Resources
IP Telephony
http://voiceXML…
MRCP
Databases,
Web Services,
Persistent
Business logic
PSTN
SIP
Web Server
VoiceXML Server
RTP
Media Gateway,
Signaling Server
& Call Router
Alternately,
use IP-PBX and it’s interfaces
10
Requirements
• Global deployable: interfaces, approvals
• Cost-effective scaling, including scale down
• Media, signaling & call routing (both ways)
• Highly available at minimum added cost
• SS7 connectivity
– SS7 controlled inter-machine trunks can be
significantly less expensive than ISDN
11
IP-PBX Approach
• Typically supports ISDN, but not SS7
• Can be expensive to scale up
• Can be expensive to distribute gateway
functions to multiple cities
12
Gateway Approach
Solution requires multiple elements
• Media gateway
• Signaling gateway
• Call routing control
– Esp. PSTN to SIP routing
– Media gateway controller,
softswitch or equiv.
• Example: Cisco AS5300 VoIP Gateway
– Requires PGW-2200 Softswitch ($20,000) to
provide basic call routing
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Integrated Solutions
• NMS Vision Media Gateway
and Signaling Server
• Cantata IMG 1010
Characteristics
• Includes call routing
• ISDN, SS7 & Channel
Associated Signaling
• Global approvals
• Scalable in 1U/2U increments
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• Centralized or distributed deployments
Basic Installation
GW
SIP-based
Services
Platform
Switch
• ISDN signaling, or
• Channel-associated
signaling (CAS)
SS7
NCC-ISUP
SIP
T1/E1 Voice
RTP
15
Small SS7 Configuration
• SS7 signaling
GW
DACS
Sig Svr
Switch
SIP-based
Services
Platform
• DACS separates
voice and
signaling traffic
-OR-
GW
Sig Svr
Switch
SIP-based
Services
Platform
• Signaling Server
separates voice
traffic
SS7
NCC-ISUP
SIP
T1/E1 Voice
RTP
16
Large SS7 Configuration
• SS7 signaling
GW
GW
...
Switch
GW
SIP-based
Services
Platform
• Dedicated T1/E1
Inter-machine
trunks (IMTs) for
voice traffic
Sig Svr
SS7
NCC-ISUP
SIP
T1/E1 Voice
RTP
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High Availability
• Media scale by trunks and trunk groups
• N+1 redundancy for media gateways
• Call routing tables (PSTN # to SIP URI)
distributed to media gateways
• SS7 signaling 1+1 redundant
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Redundant SS7 Configuration
• SS7 signaling
GW
GW
...
Switch
GW
SIP-based
Services
Platform
• Duplicated
Signaling Servers
for high
availability
Sig Svr
Sig Svr
SS7
NCC-ISUP
SIP
T1/E1 Voice
RTP
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Redundant SS7 Signaling
• 2 servers – 1 point code
• Active-active for MTP1 &
MTP2
• Active-standby for MTP3
and above
• Secondary traffic routed
to Primary via dedicated
Ethernet
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Scalability
• Media Gateway
– 8 or 16 E1/T1s per 1U
– Mounts in standard racks
– Up to 20 Gateways per
Signaling Server (pair)
• Signaling Server
– 4, 16, or 32 signaling links
– Redundant pair for high
availability
21
Other PSTN Issues
• Limited inter-city PSTN capacity in many
emerging markets
• Gateway located in capital city means poor
service for callers in secondary cities
• Inter-city PSTN calls expensive
• Inter-city IP capacity available and lower cost
Solution
Integrated IP-based solution with 1U elements
distributed to minimize recurring costs
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Highly Distributed Configuration
SSP
SSP
GW
STP
SSP
23
• Decrease networking costs,
simplify management
GW
STP
SSP
• Gateways near switches,
signaling servers near STPs
GW
GW
Sig Svr
Sig Svr
SIP-based
Services
Platform
SS7
NCC-ISUP
SIP
T1/E1 Voice
RTP
Conclusions
• Develop new communications applications on
IP-based platforms
• Obtain PSTN connectivity from VoIP service
providers where available and affordable
• Leverage IP-PBX connectivity when present
• Use integrated gateways for
–
–
–
–
–
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Global reach
SS7 connectivity
Cost-effective scalability
Cost-effective availability
Flexibility
Questions?
Brough Turner
rbt @ nmss.com
Blog: http://blogs/nmss.com/communications/
PDF version to be posted today
Recorded version to be posted tomorrow