Multi-Service Backbone Design Drivers behind Next Generation Networks Vijay Gill Jim Boyle

Multi-Service Core What is it? Why Multi-Service? Options for delivering Multiple services

What mul·ti·serv·ice adj. Offering or involving a variety of services IP, Voice, Private Line, VPNs, ATM, FR

Why $700 Billion – Voice, Fax, Modem Market Telco Companies Day Job Voice based communications is still ~ 90% of Global Telco revenue Voice bit is ~ 14 x more expensive than data bit

Ways to Deliver Multiple Services Multiple Backbones One for each Service (SONET, ATM/FR, IP) Common Backbone Layer multiple services on top of a common transport fabric

Multiple Backbones Application Aware Dedicated Infrastructure used to implement each application – PSTN, FR, ATM, Private Line Discourages Diversity Needs Large Market Demand before it is cost effective to go out and build the support infrastructure ATM/SONET infrastructure More boxes, complex management issues Hard to upgrade bandwidth in sync for all backbones

Common Backbone Application Unaware Characterized by the new breed of Telcos Rapid innovation Clean separation between transport, service, and application Allows new applications to be constructed without modification to the transport fabric. Less Complex (overall)

Why A Common Backbone? Spend once, use many Easier capacity planning and implementation Elastic Demand 1% price drops result in 2-3% rise in demand – Matt Bross, WCG Increase of N on edge necessitates 3-4 N core growth Flexibility in upgrading bandwidth allows you to drop pricing faster than rivals

Source: KPCB Historical and forecast market price and unit cost of Transatlantic STM-1 circuit (on 25 year IRU lease) 2,000 4,000 6,000 8,000 10,000 12,000 14,000 16,000 18, Price per STM-1 ($m) PRICE COST Bandwidth Blender - Set on Frappe

Some Facts There is no absolute way to measure any statistic regarding the growth of the Internet The Internet is getting big, and it's happening fast Source: Robert Orenstein

“ Already, data dominates voice traffic on our networks” -Fred Douglis, ATT Labs

Solution Leverage packet based technology Multi service transport Fabric Optimize for the biggest consumer - IP Provide a loosely coupled access point for service specific networks (e.g. IP good, per-call signaling bad)

Solution Internet (IP) VPN Voice/Video CES Voice/Video CES Multi Service IP Transport Fabric

Requirements Isolating inter-service routing impacts Address space protection/isolation Fast Convergence (Service Restoration) Providing COS to services

Requirements Support multiple services Voice, VPN, Internet, Private Line Improving service availability with stable approaches where possible

LSPs re-instantiated as p2p links in IGP e.g. ATL to DEN LSP looks like p2p link with metric XYZ Run multiple instances of IGPs (TE and IP) Stabilize The Edge

Stabilize The Core Global instability propagated via BGP Fate sharing with the global Internet All decisions are made at the edge where the traffic comes in Rethink functionality of BGP in the core

COS Mark service bits upon ingress WRR on trunks configure max time-in queue Avoid congestion But when congested, monitor that traffic delivered in line with objectives Crude (compared to what?) but effective.

Implementation Approaches Pure IP Layer 2 tunneling (aka CCC, AToM) RFC2547 (base and bis) Merged IGP Multi process IGP IP + Optical Virtual Fiber Mesh Protection GMPLS (UNI, NNI)

IP Only Fiber DWDM / 3R IP / Routers Removal of an entire layer of active optronics Directly running on DWDM Technology for Private Lines and Circuit Emulation isn’t here yet Fate sharing with Global Internet

LSP Distribution LDP alongside RSVP Routers on edge of RSVP domain do fan-out Multiple Levels of Label Stacking Backup LSPs Primary and Backup in RSVP Core Speed convergence Removes hold down issues (signaling too fast in a bouncing network) Protect path should be separate from working There are other ways, including RSVP E2E

LDP Service Edge RSVP-TE Core

IP + Optical Fiber DWDM / 3R IP / Routers Optical Switching Virtual Fiber Embed Arbitrary fiber topology onto physical fiber. Mesh restoration. Private Line Increased Velocity of service provisioning Higher cost, added complexity

Peter’s “Ring of Fire” Edge Core Optical Switch DWDM Terminal Backbone Fiber Metro Collectors

IP + Optical Network Big Flow Out of port capacity, switching speeds on routers? Bypass intermediate hops

Dual Network Layers Optical Core (DWDM Fronted by OXC) Fast Lightpath provisioning Attach Metro collectors in Mega PoPs via multiple OC- 48/192 uplinks Metro/Sub-rate Collectors Multiservice Platforms, Edge Optical Switches Groom into lightpaths or dense fiber. Demux in the PoP (light or fiber) Eat Own Dog Food Utilize customer private line provisioning internally to run IP network.

Questions (3) Jim Boyle Vijay “Route around the congestion, we must” Gill Nota Bene – This is not a statement of direction for our companies! Many thanks to Tellium (Bala Rajagopalan and Krishna Bala) for providing icons at short notice!