1. User Group May 24, 2005

2. Metro Ethernet- Table of Contents I.Why Ethernet? II.Metro Ethernet Product Description III.Metro Ethernet Product Comparison IV.Metro Ethernet Product Availability V.Metro Ethernet Development Strategy VI.Ethernet over SONET Product Description VII.Ethernet over SONET Development Strategy

3. Why Talk About Ethernet? In 2002, Ethernet was 1% of a $23B market…By 2007, Ethernet will be 10% of a $38B market – Yankee Group “…services are becoming clearly delineated, and customers have begun to ask for the services by name…the service gaining prominence in the metro market in the next 3 years” – Yankee Group

4. Metro Ethernet addresses customer demand for guaranteed bandwidth and QoS –Reduce bandwidth contention – no longer a “Best Effort” service –SLAs, especially for service availability –Support for voice and specialized applications Retains the economic NMLI/GigE value proposition –Very high bandwidths at an affordable price –Economically scales from 10Mbps up to 1000Mbps –Customers can transparently leverage low-cost network equipment (CPE) and employee expertise Why BellSouth Metro Ethernet?

5. Education Healthcare Financial Government Metro Ethernet Application Examples

6. Premium Service - Feature Description Committed Bandwidth Rate (CBW) –CIR-like capability is designed to eliminate bandwidth contention; Customer gets the bandwidth they subscribe to –Minimum BW across the switched core network that will always be available to transport data originating from a specific customer location –10, 20, 50, 100, 250, 500 Mbps speeds available –Bandwidth overhead included in CBW Rate IFG, Broadcast Overhead Packets above CBW limit are dropped –Uses Policing Policing on Ingress Port (Access) No Traffic Shaping Utilized No Egress Policing (Full Line Rate) –Basic Building Block for Premium Service

7. Premium Service - Feature Description CBW with Bursting –Burstable bandwidth not guaranteed; only when available –Burst speeds are limited to ingress port speed (line rate) –Each CBW is associated with a maximum burst rate: CBW (Mbps)Maximum Burst Rate (Mbps) 10100 20100 50100 1001000 2501000 5001000 –CBW without bursting – “Fixed mode” –CBW + bursting – “Burst mode”

8. Premium Service - Feature Description REMOTE SITES Host Site 100 Mbps CBW 50 Mbps CBW 100 Mbps CBW 250 Mbps CBW – Fixed on a 1000Mbps Port 400 Mbps 300 Mbps 100 Mbps 250 Mbps 100 Mbps

9. Premium Service - Feature Description CBW with “Priority Plus” –Provides customers a means of managing their real-time delay- sensitive traffic (VoIP, video, data mirroring) –Priority Plus traffic carries the highest priority on network –Cisco 7609 examines IP Precedence (IPP) bits value on incoming traffic 8 priority levels into ingress port (0 – 7) IPP = 5 - Priority Plus IPP = 1-4, 6, 7 – Treat as CBW Priority Plus traffic is directed to a low-latency trunk queue Amount of priority traffic is limited as a percentage of CBW Priority traffic exceeding CBW percentage limit will be discarded –Requires Committed Bandwidth (CBW)

10. Premium Service - Feature Description “Q Forwarding” –Supports VLAN Aggregation IEEE 802.1Q Specifications Supports up to 2 Layers of VLAN Stacking Maximum Frame MTU 1536 Bytes –Targeted to ISPs and Carriers requiring VLAN segregation Reduces cost for the ISP Provides security for the ISP’s customers –Customer Access Port BellSouth & Customer agrees to 802.1Q Tag Q-tag designates specific customer Tag passed to aggregation port –Service Mix CBW CBW w/Priority –Frame Header MTU Size Increases by 4 Bytes for each Tag Added

11. Aggregation with Q Forwarding Cisco 7609 Customer C Host Customer A Customer B Customer A VLAN tag = 55 Customer B VLAN tag = 32 Customer C VLAN tag = 55 500M CBW 21 22 24 21 22 24

12. Customer Network Management Web-enabled GUI on customer’s desktop Primary Capabilities: –Service Status Monitoring –Performance Monitoring and Reporting Port Utilization Frame Volume Errors QoS Threshold Exceptions Latency and Availability –Alarm Surveillance and Fault Reporting Real-time critical and major alarms Available to Premium customers Tariffed in Metro Ethernet tariff as “Metro Ethernet Reporting” Secure passwords and ID cards provided Enables Service Level Agreements (SLAs)

13. Service Comparison Metro Ethernet “Basic” Metro Ethernet “Premium” 10, 100, 1000 Mbps switched Best-effort service Data transport only No port aggregation Uses pricing “bands” to eliminate mileage Full-duplex 10Mbps Fiber and metallic interfaces No service guarantees Cisco 7609 & Alcatel 10, 20, 50, 100, 250, 500 Mbps (switched) Committed bandwidth with bursting option VOIP supported using traffic prioritization 802.1Q VLAN stacking supports traffic aggregation across a common port Uses pricing “bands” to eliminate mileage Full duplex 10Mbps Fiber and metallic interfaces SLAs supported by CNM Cisco 7609 only Dedicated GigE/Fast Ethernet will be offered in the ME tariff

14. Metro Ethernet Premium Availability Available in the following Metros: Birmingham, AL; Miami, FL; West Palm Beach, FL; Orlando, FL; Jacksonville, FL; Ft. Lauderdale, FL; Atlanta, GA; New Orleans, LA; Charlotte, NC; Raleigh, NC; Wilmington, NC; Charleston, SC; Columbia, SC; Greenville, SC; and Spartanburg, SC Scheduled for deployment during 2005: Louisville, KY; Nashville, TN Additional switch deployments will be determined by market need or “anchor tenant”

15. Metro Ethernet Development Strategy Ethernet over Copper –Will enable mid-band speeds (2Mbps, 4Mbps, 8Mbps) Virtual Ethernet Service –Multiple VLANs across single Ethernet port –Each can have specific QoS Automatic Protection Switching –Fiber switching in the event of a failure Carrier Class SLAs –Tightened SLAs on network availability and latency –Additional SLAs on jitter and error bits

16. Metro Ethernet for Resale For more information on the GSST product for resale, contact your Local Support Manager (LSM) at 1-800-511-6555, or your Local Contract Manager (LCM)

17. THANK YOU!