We know your network But we also know

We know your network. But we also know your name Extended Native LAN Product Overview

What is ENLAN? • ENLAN is an extension of the NLAN connectivity between two or more TWTC markets across the TWTC IP Backbone. Speeds from 2 M to 1 G. • Only one instance of ENLAN per market is required. • Each of the markets may have more than one location. • Local “access” to the locations in each market are purchased via the normal SNLAN product. • Connecting via Elite NLAN is NOT an option. 2

Why ENLAN? • NLAN is a metro solution • Many of our customers are multi-market • TWTC has a powerful IP Infrastructure to support customer multi-market needs 3

ENLAN Reach is SAME as IP Reach 4

Basic Uplink Architecture The customer’s VLAN in one city is mapped to an MPLS tunnel at the Edge Router. IP Backbone IP Core Routers Juniper M 480 M 960 etc 1 and 10 G Uplinks MPLS IP Edge Router Ethernet / VLAN 1 and 10 G Uplinks Metro Switch Cisco 7609 Edge Switch: Cisco 3 xxx, 49 xx, etc 5 Metro Ethernet Ring

What is an MPLS tunnel? • Multi-Protocol Label Switching creates a label switched path similar to a virtual circuit. • It is similar to the MEF term of an EVC. Also similar to VCs in Frame Relay or ATM in that is sets a pre-determined “path” through the network for customer traffic. • ENLAN over MPLS is a best effort service unless Co. S is purchased. • Our customer’s NLAN traffic is mapped to a specific MPLS tunnel or path based on the destination desired; logical separation is still maintained to provide the same level of “security” that is found in FR or ATM networks. 6

End-to-End Architecture TWTC IP Backbone L 2 VPN Tunnel Cisco 7609 Cisco 3400 Customer Premise EXAMPLE of two customer sites connected by ENLAN CPE City A 7 Customer Premise City Z

“Point-to-Point” ENLAN Example 8

Multipoint ENLAN • • ENLAN product is built differently as a multipoint or “full mesh” product, as opposed to only connecting two markets. MP ENLAN connection extends between the IP POPs from three or more TWTC Cities. • Local Ethernet connectivity, via the SNLAN product, is still required to connect the customer locations in each city to the IP POP in each city. • Multipoint ENLAN not priced differently than p 2 p, but is important to distinguish at the time of SOF/OE. • Changing from two markets (p 2 p) to 3 or more is briefly service impacting to the customer due to config. changes. 9

Multi-point ENLAN Example 10

End-to-End Architecture: MP Cisco 7609 nnel Cisco 7609 TWTC IP Backbone L 2 V PN T L 2 VPN Tunnel L 2 Tu VPN Cisco 3400 CPE City B unne l Cisco 7609 EXAMPLE of three customer sites connected by ENLAN Cisco 3400 CPE City A 11 CPE City C Cisco 3400

Multi-point Technical Implementation • Uses VPLS to make backbone appear as a switch to all sites for each customer. • VPLS is a networking approach enabled at the edge router, or “HAGG, ” which extends the customer’s Ethernet LAN between multiple NLAN’s. • From the high speed aggregation router (HAGG), the ENLAN traffic will be sent though the backbone using VPLS to the HAGG on the destination NLAN site. • BGP is used to build the IP/MPLS LSP mesh when 3 or more markets are requested. • The edge router acts as a layer 2 learning switch building a MAC table to determine which LSP to send a frame over. 12

Customer Uses for ENLAN • The ENLAN applications mirror those for existing SNLAN customers. • Applications include typical bulk file transfers (e. g. Imaging, CAD/CAM, data repository transfers), private intranet, LAN/email, remote office connectivity into the HQ, etc. • Default/Basic service is not a dedicated bandwidth technology and should never be sold as such; it mirrors a best effort “virtual circuit” environment. • Premium Class of Service available on ENLAN if the metro SNLAN is also enabled for Co. S. • Flat fee for Co. S allows most all marked traffic to flow between markets. 13

VLAN Tagging • Individual tags or unlimited tags should be ordered in the NLAN product suite. • ITS is NOT SUPPORTED on the ENLAN product beyond a single tag: the single tag is equivalent to UTS in that it still only consumes a single S-Tag. • ENLAN CANNOT be used in conjunction with the Wholesale SNLAN product because of VLAN tagging issues. 14

Additional ENLAN Notes • ENLAN may be used to connect adjacent cities; the price may be waived but the technology and VLAN tag limits per prior slides remains in place. • ENLAN cannot exceed 1 G of bandwidth. • E-Line should always be considered over ENLAN when the service request is point to point only and the city pairs match the Nationl Ethernet footprint. • Customer can “manage” traffic into and out of a market and limit the size of the ENLAN instance per market to whatever they want. • When connecting a market that has more than one metro location, it does not make any difference which address you associate the ENLAn instance with. 15