14-sridhar%20ramachandran.ppt

Sridhar RamachandranSridhar RamachandranChief Technology OfficerChief Technology Officer

sri@nextone.comsri@nextone.com

Core Session Controller

NexTone CustomersNexTone Customers

NexTone’s Session Controllers aredeployed in over 100 carrier and service provider

networks for a total capacity of over 2 BILLION minutes a month

NexTone’s Session Controllers aredeployed in over 100 carrier and service provider

networks for a total capacity of over 2 BILLION minutes a month

What is a Session Controller?What is a Session Controller?

Point of control for multimedia signaling and media− Service protection− Network isolation and insulation

Other names− IP-IP Gateway− Back to back gateway− Session Border Control− Border Session Control

Point of control for multimedia signaling and media− Service protection− Network isolation and insulation

Other names− IP-IP Gateway− Back to back gateway− Session Border Control− Border Session Control

Problems where VoIP has proven effectiveProblems where VoIP has proven effective

Transport

Switching

Interconnect− Carrier – Carrier− Enterprise – Carrier

Applications

Transport

Switching

Interconnect− Carrier – Carrier− Enterprise – Carrier

Applications

• Top and bottom line enhancing• Flexibility and enforceability are key• Control points

Growth in VoIP PeeringGrowth in VoIP Peering

ITXC Carries Record Voice Call Volumes for Holidayshttp://www.itxc.com/pages/press/release229.html

“In past years, our carrier customers used ITXC to complete their subscribers’ calls because our VoIP technology allowed us to provide them high quality at low prices. Usually, the only VoIP involved was within our network. Now carriers also choose

ITXC for interconnection because they themselves are deploying VoIP equipment in their own networks or even at their subscribers’ premises. Our technology allows these carriers to connect their VoIP networks to ours at much less cost than a

legacy PSTN interconnect and with much greater flexibility.”

In the fourth quarter of 2003, over one third of ITXC's traffic was originated or terminated through a direct VoIP interconnect between ITXC.net® and the network of another carrier. ITXC has VoIP interconnects with over 140 carriers or service providers in 60 countries and supports VoIP traffic exchange with a wide variety of network equipment vendor platforms

based on either Session Initiation Protocol (SIP) or H.323 call control protocol.

iBasis Posts Record VoIP Call Volume During New Year's Dayhttp://www.ibasis.com/news/PR2004/pr01072004.htm

"In addition to setting an overall record for traffic, we are experiencing a record volume of traffic that enters or exits the iBasis Network as IP traffic," said Ofer Gneezy, president and CEO of iBasis. "Major carriers have been deploying VoIP

infrastructure to support both retail services and direct VoIP carrier interconnects. At the same time, new service providers are delivering VoIP services directly to residential and business consumers. Both can realize significant cost efficiencies by

establishing direct VoIP interconnections with our proven global VoIP infrastructure. "More than 70% of iBasis traffic either originates or terminates through our direct VoIP interconnects with service providers. Direct VoIP interconnects require significantly less capital expense in the iBasis network than legacy TDM interconnects. In addition, we are enabling our customers to more fully benefit from the efficiencies of VoIP and the public Internet for global

telecommunications."

VoIP Peering RequirementsVoIP Peering Requirements

− Flexibility• Media and Signaling Routing based on trust boundaries• “Any-to-any” interworking – SIP, H.323, multiple vendor interoperability • High Performance and Scale• “On-demand” Media Processing

− Leverage and enforce existing peering agreements• Call Admission Control

Prevent Denial of Service attacks and service abuse/theft• Call accounting

Call Detail Record (CDR) generation and reporting• Topology Hiding

Go across address boundaries− Control Points

• Segmentation/classification of traffic

− Flexibility• Media and Signaling Routing based on trust boundaries• “Any-to-any” interworking – SIP, H.323, multiple vendor interoperability • High Performance and Scale• “On-demand” Media Processing

− Leverage and enforce existing peering agreements• Call Admission Control

Prevent Denial of Service attacks and service abuse/theft• Call accounting

Call Detail Record (CDR) generation and reporting• Topology Hiding

Go across address boundaries− Control Points

• Segmentation/classification of traffic

What are Carriers’ session control needs?What are Carriers’ session control needs?

Call routing with multiple business models:− Wholesale− Transit− Pre-paid− Post-paid/retail

Service brokerageSpecial applications− Permissive dialing

Call routing with multiple business models:− Wholesale− Transit− Pre-paid− Post-paid/retail

Service brokerageSpecial applications− Permissive dialing

Edge SCEdge SC

Session Controller PlacementSession Controller Placement

SIP Network

EnterprisePeering

EnterprisePeering

PSTN

BroadbandH.323 Network

CarrierPeeringCarrierPeering

BroadbandNAT Traversal

BroadbandNAT Traversal

PSTNOrig/Term

PSTNOrig/Term

Edge SCEdge SC

Softswitch

Core SCCore SC

Edge SCEdge SC

AggregationAggregation

Multiple interconnects between same carriersMulti-stage and hierarchical call admission controlCore SC maintains notion of aggregate capacity

Multiple interconnects between same carriersMulti-stage and hierarchical call admission controlCore SC maintains notion of aggregate capacity

Partner CarrierIP Network

CarrierIP

Network

Edge SCCore SC

Edge SC

Merits of this ApproachMerits of this Approach

No “control” protocolCall admission control based on network egress policiesAbility to add other service selection logic− Applications− Quality of Service demanded or provisioned

Call routing with mixed business models− Wholesale− Pre-paid or post-paid− Transit

Normalized and vendor independent call routing− SIP only

No “control” protocolCall admission control based on network egress policiesAbility to add other service selection logic− Applications− Quality of Service demanded or provisioned

Call routing with mixed business models− Wholesale− Pre-paid or post-paid− Transit

Normalized and vendor independent call routing− SIP only

Other AdvantagesOther Advantages

Implementation flexibility− Redirect server− Stateful SIP proxy− B2BUA

Core SC function can be integrated into Edge SCLeverage TRIP (rfc 3219) and TGREPView Edge SCs and Gateways as originators and terminators of sessions

Implementation flexibility− Redirect server− Stateful SIP proxy− B2BUA

Core SC function can be integrated into Edge SCLeverage TRIP (rfc 3219) and TGREPView Edge SCs and Gateways as originators and terminators of sessions

What about the “Softswitch”?What about the “Softswitch”?

“Control” paradigm has limited effectiveness− Gateway control− Call control

Softswitch designed for a “closed” network− MGCP/MEGACO to provide total control of internal network

How does one build a fabric of softswitches?

“Control” paradigm has limited effectiveness− Gateway control− Call control

Softswitch designed for a “closed” network− MGCP/MEGACO to provide total control of internal network

How does one build a fabric of softswitches?

SummarySummary

Session Controllers are essential for VoIP peeringCore Session Controllers provide higher level functionality, based on SIP signaling

Session Controllers are essential for VoIP peeringCore Session Controllers provide higher level functionality, based on SIP signaling

Thank You.

sri@nextone.com ; +1-240-912-1301

What about the “Softswitch”?What about the “Softswitch”?

“Control” paradigm has not proven effectiveSoftswitch designed for a “closed” network− MGCP/MEGACO to provide total control of internal network

VoIP interconnects challenge the Softswitch “control” paradigm− Interconnects = carrier peering, and MGCP/MEGACO “control” of 3rd party

networks not viable− SIP/H323 typically added as after-thought to interwork trusted devices

Softswitch domains (and VoIP interconnects should never be trusted)VoIP Interconnect Solution:− Keep SS7 and MGs at the edge of the VoIP network, Softswitch as “cluster

controller” to help handle SS7/C7− Introduce Session Controllers to manage VoIP peering and interconnects

between carriers and enterprises− Overcome lower layer (Layer 2/3) IP issues call-by-call – NAT/PAT, security,

VLANs etc

“Control” paradigm has not proven effectiveSoftswitch designed for a “closed” network− MGCP/MEGACO to provide total control of internal network

VoIP interconnects challenge the Softswitch “control” paradigm− Interconnects = carrier peering, and MGCP/MEGACO “control” of 3rd party

networks not viable− SIP/H323 typically added as after-thought to interwork trusted devices

Softswitch domains (and VoIP interconnects should never be trusted)VoIP Interconnect Solution:− Keep SS7 and MGs at the edge of the VoIP network, Softswitch as “cluster

controller” to help handle SS7/C7− Introduce Session Controllers to manage VoIP peering and interconnects

between carriers and enterprises− Overcome lower layer (Layer 2/3) IP issues call-by-call – NAT/PAT, security,

VLANs etc

Core Session ControllerCore Session Controller

IntroductionWhat is a session controller?Growth in VoIP peeringNeed for more control at the coreView of softswitchCore session controller fabric

IntroductionWhat is a session controller?Growth in VoIP peeringNeed for more control at the coreView of softswitchCore session controller fabric