1. WorldCom Proprietary & Confidential Page 1 MAE® Services Tom Bechly February 11, 2002 NANOG 24 IX Panel

2. WorldCom Proprietary & Confidential Page 2 L2 Encapsulation Overhead Comparison of Framed payload – independent of transmission media EncapsulationFixedIP Payload 64 bytes IP payload 1500 bytes Bytes% Ethernet w/o 802.1q1878.098.8 Ethernet w 802.1q2274.498.6 RFC2427(routed,SNAP header) 1284.299.2 RFC2427(routed,NLPID protocol) 691.499.6 RFC2684 (ATM AAL5 SNAP)1260.488.4

3. WorldCom Proprietary & Confidential Page 3 Frame Interface Efficient utilization of bandwidth CPE POS Router Ports are economic and dense Service provisioning is straightforward for both Customer and MAE facility No routing information exchanged between MAE facility and CPE MAE services technology can change while preserving stable service level interface Colo-Neutral architecture (i.e., WAN protocol)

4. WorldCom Proprietary & Confidential Page 4 MAE ® FE Service POS interface with frame relay encapsulation –PVCs based on Juniper ccc technology –“Best Effort” service, No policing or shaping –Supports ANSI Annex D LMI –DLCIs from 512 to 1007 Access speeds are OC3, OC12, and OC48 Customers provision PVCs via PeerMaker SM Provisioner Sites have colocation and transport MAE Chicago SM FE Service Facility 10/01 MAE New York SM FE Service Facility 3/02

5. WorldCom Proprietary & Confidential Page 5 Frame/ATM Interworking Interworking Switch Border Router Border Router ATM Switch ATM Frame Relay

6. WorldCom Proprietary & Confidential Page 6 Planned Service Enhancements Frame/ATM Interworking –Deploy Frame Relay interworking switch at existing MAE ATM facilities –ATM PVCs can be mapped to Frame PVCs –OC3, OC12, and OC48 Frame access to exchange –Interworked PVCs provisioned via PeerMaker SM Provisioner –Planned for mid 2002