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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
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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
IP-based Services & Systems • IP call centers, IP PBXs • Self-service customer voice portals
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)
Skyperegistrations:171M VoIP Adoption VoIPsubscribers:38M Fixed PSTN: 1.2B Mobile PSTN: 2.7B
http://voiceXML… Web Server 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 SpeechResources IP Telephony IXC Gateway MRCP Databases, Web Services, Persistent Business logic SIP VoIP IXC PSTN RTP VoiceXML Server
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
http://voiceXML… Web Server Nominal Solution • Provide PSTN gateway with IP-based application SpeechResources IP Telephony MRCP Databases, Web Services, Persistent Business logic PSTN SIP RTP VoiceXML Server Media Gateway,Signaling Server& Call Router Alternately,use IP-PBX and it’s interfaces
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
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
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
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 • Centralized or distributed deployments
SS7 NCC-ISUP SIP T1/E1 Voice RTP Basic Installation GW SIP-based Services Platform Switch • ISDN signaling, or • Channel-associated signaling (CAS)
SS7 NCC-ISUP SIP T1/E1 Voice RTP Small SS7 Configuration • SS7 signaling • DACS separates voice and signaling traffic • Signaling Server separates voice traffic GW DACS Sig Svr SIP-based Services Platform Switch -OR- GW SIP-based Services Platform Sig Svr Switch
SS7 NCC-ISUP SIP T1/E1 Voice RTP Large SS7 Configuration • SS7 signaling • Dedicated T1/E1 Inter-machine trunks (IMTs) for voice traffic GW GW SIP-based Services Platform Switch . . . . . . GW Sig Svr
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
SS7 NCC-ISUP SIP T1/E1 Voice RTP Redundant SS7 Configuration • SS7 signaling • Duplicated Signaling Servers for high availability GW GW SIP-based Services Platform Switch . . . GW Sig Svr Sig Svr
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
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
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
STP STP SSP SSP SSP SSP SS7 NCC-ISUP SIP T1/E1 Voice RTP Highly Distributed Configuration • Gateways near switches, signaling servers near STPs • Decrease networking costs, simplify management GW GW Sig Svr SIP-based Services Platform Sig Svr GW GW
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 • Global reach • SS7 connectivity • Cost-effective scalability • Cost-effective availability • Flexibility
PDF version to be posted today Recorded version to be posted tomorrow Questions? Brough Turner rbt @ nmss.com Blog: http://blogs/nmss.com/communications/