1. © 2007 AT&T Knowledge Ventures. All rights reserved. AT&T and the AT&T logo are trademarks of AT&T Knowledge Ventures. Subsidiaries and affiliates of AT&T Inc. provide products and services under the AT&T brand. AT&T Proprietary (Internal Use Only) Network-Based VPN AT&T Private Network Transport Presenter

2. Page 2 © 2007 AT&T Knowledge Ventures. All rights reserved. AT&T and the AT&T logo are trademarks of AT&T Knowledge Ventures. Subsidiaries and affiliates of AT&T Inc. provide products and services under the AT&T brand. AT&T Proprietary (Internal Use Only) Protect reliability and application performance High performance and flexible bandwidth ready for growth Quick integration of new devices and applications Avoid downtime Increase efficiency and lowering TCO by leveraging VPN and IP applications Productivity gains from collaboration Services over IP Enhanced communications through Video over IP Transaction efficiencies across their entire supply chain Proliferation of applications and devices Protecting investments through technology migrations Optimizing their infrastructure Assuring security and availability in a complex environment Confidence in the tools and platforms to manage appropriately Hopeful about new Capabilities Concerns about Performance Protecting their Users’ Experience What Customers are Telling Us

3. Page 3 © 2007 AT&T Knowledge Ventures. All rights reserved. AT&T and the AT&T logo are trademarks of AT&T Knowledge Ventures. Subsidiaries and affiliates of AT&T Inc. provide products and services under the AT&T brand. AT&T Proprietary (Internal Use Only) Data Center Customer Branch AT&T Global Network AT&T Internet Data Center Internet Storage Web / App Server Dial DSL Cable WiFi Ultra-Available Ring Dial DSL Cable WiFi Supplier VPN Remote Access Network Based Firewall Managed Router Web Site Managed Firewall VoIP Site to Site VPN IP Sec MPLS VPN Intrusion Detection VPN Remote Access Personal Firewall Customer Requirements

4. Page 4 © 2007 AT&T Knowledge Ventures. All rights reserved. AT&T and the AT&T logo are trademarks of AT&T Knowledge Ventures. Subsidiaries and affiliates of AT&T Inc. provide products and services under the AT&T brand. AT&T Proprietary (Internal Use Only) Network and Service Convergence One highly scalable and robust core network to support Convergence: – Voice, Video and Data Convergence – Intranet, Extranet and Internet Convergence – Layer 2 and Layer 3 service convergence An Infrastructure that provides for easy migrations and interoperability between different endpoints. Built upon standards-based IP architecture paradigm and elements Transparent to end-user applications Supporting current and emerging application paradigms Enables multiple logical networks on one common network infrastructure Logical network for each service (FR, ATM, ETHERNET, Layer-3 VPN, MIS, VoIP) Logical network for each customer intranet/extranet VPN with inherent security capabilities Why MPLS-based Architecture?

5. Page 5 © 2007 AT&T Knowledge Ventures. All rights reserved. AT&T and the AT&T logo are trademarks of AT&T Knowledge Ventures. Subsidiaries and affiliates of AT&T Inc. provide products and services under the AT&T brand. AT&T Proprietary (Internal Use Only) AT&T MPLS Network Customer AccessCustomer Applications Security management, MPLS Security on Par with Frame Relay and ATM Implement Enterprise Apps: VoIP, Intranet, e-Mail, E-Commerce, Content Hosting MPLS VPN implement IP services, meshed networks T1 T3 OCx Point to Point Connection A dedicated, replicable, and secure path through the AT&T MPLS Network Merge Networks (FR, ATM,IP) The security of FR with benefits of IP networking. Internet access, security and Quality of Service all on one network VPN A network-based VPN, with all of the benefits of traditional IP-based VPNs without having to invest in additional VPN equipment or management Merge Networks PPP AT&T Private Network Transport AT&T POP

6. Page 6 © 2007 AT&T Knowledge Ventures. All rights reserved. AT&T and the AT&T logo are trademarks of AT&T Knowledge Ventures. Subsidiaries and affiliates of AT&T Inc. provide products and services under the AT&T brand. AT&T Proprietary (Internal Use Only) Access Speeds Full T1, MLPPP, Fractional T3, Full T3, Ethernet, OC3, OC12 and OC48 Addressing Allows both private (example10.x.x) and public addressing Routing protocol Supports both Static and BGP (depending on model) Internet Access MPLS PNT does not provide internet access Internet access can be provided by purchasing Internet ports and will incur additional charges Management Supports both managed and/or unmanaged options Private Network Transport Service Features

7. Page 7 © 2007 AT&T Knowledge Ventures. All rights reserved. AT&T and the AT&T logo are trademarks of AT&T Knowledge Ventures. Subsidiaries and affiliates of AT&T Inc. provide products and services under the AT&T brand. AT&T Proprietary (Internal Use Only) Cost Effectiveness – Significant cost savings – 10%-40% compared to “Traditional VPN’s” – Merge both Internet and private networking needs over one network PPP local access Guaranteed Full Port Speeds Native IP Network Class of Service Resiliency built into the AT&T MPLS Network and redundancy available for your site Security on par with Frame Relay or ATM Scalability – Network based service can be scaled easily in terms of sites and speeds. – Fully meshed connectivity to all sites with just a single connection into the VPN Simplicity no tunnel or PVC provisioning and maintenance required Flexibility to add or deletes sites and routes as needed Reach mesh network with an industry leading United States Footprint Excellent Customer Support Usage-based Billing options Private Network Transport Value Proposition

8. Page 8 © 2007 AT&T Knowledge Ventures. All rights reserved. AT&T and the AT&T logo are trademarks of AT&T Knowledge Ventures. Subsidiaries and affiliates of AT&T Inc. provide products and services under the AT&T brand. AT&T Proprietary (Internal Use Only) Security Services Managed Firewall Service-Server-Based, Router-Based, Premises-Based Managed Intrusion Detection Service Network Scanning Service IP Applications and Management PNT Value Cost Effectiveness Guaranteed Full Port Speeds Extensive U.S. Domestic Reach via the AT&T MPLS Network High Performance Network Predicatable Performance (QoS) Security Services Project Management Simplicity of One Stop Shop with Flexible Billing Options Excellent Customer Support Think about your Total Cost of Ownership!! Private Network Transport Your Roadmap to Value

9. Page 9 © 2007 AT&T Knowledge Ventures. All rights reserved. AT&T and the AT&T logo are trademarks of AT&T Knowledge Ventures. Subsidiaries and affiliates of AT&T Inc. provide products and services under the AT&T brand. AT&T Proprietary (Internal Use Only) Thank You!

10. © 2007 AT&T Knowledge Ventures. All rights reserved. AT&T and the AT&T logo are trademarks of AT&T Knowledge Ventures. Subsidiaries and affiliates of AT&T Inc. provide products and services under the AT&T brand. AT&T Proprietary (Internal Use Only) BACK UP SLIDES

11. Page 11 © 2007 AT&T Knowledge Ventures. All rights reserved. AT&T and the AT&T logo are trademarks of AT&T Knowledge Ventures. Subsidiaries and affiliates of AT&T Inc. provide products and services under the AT&T brand. AT&T Proprietary (Internal Use Only) A network based IP VPN Uses MPLS (IETF Standard RFC 2547) for security Provisioned on AT&T’s IP Network Does not use IP SEC (no tunnels, no encryption) No additional tunneling hardware needed Data Packet Two Labels The inner label (second-level) identifies the destination VPN and customer address Egress MPLS Edge Router removes labels from each packet The outer label (first-level) is the forwarding label for transport within the core Ingress MPLS Edge Router adds two labels to each packet Dedicated access with PPP Pure (Native IP) layer 3 solution from premises to premises Any-to-any connectivity (fully meshed) with a single connection at each site. How MPLS PNT Works