For the ultimate in high-speed connectivity, choose Systek's OC12 service. This reliable, high-speed service is ideal for Internet Service Providers, large content providers, search engines, Web hosting companies, and wholesalers. And, as with all Systek leased line services, OC12 service offers Systek's groundbreaking service level agreement, expanded global reach, and unmatched customer service and technical support.

Systek's OC12 service enables high-volume users who have outgrown their OC3 service to connect directly to Systek's award-winning global backbone. Users obtain greater bandwidth flexibility, with a 622 Mbps connection. Bandwidth commitment levels begin at 150 Mbps. OC12 service allows customers to sustain numerous simultaneous users on their corporate Web sites and provides users shorter download times.

OC12 service uses Packet over SONET (POS) technology instead of Asynchronous Transfer Mode (ATM) to maximize bandwidth. POS places the IP packet onto Point-to-Point Protocol (PPP) then SONET, which optimizes bandwidth and reduces inefficiencies in data delivery.Customers currently using OC3 service can expand their bandwidth by simply upgrading to OC12 service, rather than ordering multiple OC3 lines. Service Level Agreements are extended to OC12 customers for availability, installation, latency (speed), packet delivery, and proactive outage notification.

Burstable OC12 POS service allows you to connect directly to Systek's network via POS. It is available as a full OC12 (622 Mbps) connection with burstable commitment levels available beginning at 0-150 Mbps. Your bill is based on bandwidth commitment levels and actual usage. Take advantage of the full 622Mbps of the circuit at anytime. With Burstable OC12 service, Systek monitors the amount of bandwidth you use, and your bill is based on the usage level under which 95 percent of the samples fall. Systek disregards the top five percent of samples, so your costs will not jump to the higher usage tier just because you occasionally need additional bandwidth. Burstable OC12 is available in the following tiers:

• 0-150 Mbps sustained use
• 150.01-200 Mbps sustained use
• 200.01-250 Mbps sustained use
• 250.01-300 Mbps sustained use
• 300.01-350 Mbps sustained use
• 350.01-400 Mbps sustained use
• 400.01-450 Mbps sustained use
• 450.01-500 Mbps sustained use
• 500.01-550 Mbps sustained use
• 550.01-622 Mbps sustained use

Tiered OC-12 service provides high bandwidth dedicated access from your premises directly into a Systek hub. A full OC12 (622Mbps) circuit is provisioned, but the bandwidth is capped in increments to limit bandwidth usage. You may upgrade to another bandwidth tier at any time. There are no additional services that need to be installed, allowing for flexibility and an easy upgrade path, at a fixed monthly cost. Tiered OC12 is well-suited for ISPs predicting strong bandwidth growth in the near future and growing net-centric companies with predictable and steady traffic flows. Tiered OC12 service is available in the following tiers (connection speed caps):

• 150 Mbps
• 160 Mbps
• 180 Mbps
• 200 Mbps
• 250 Mbps
• 300 Mbps
• 350 Mbps
• 622 Mbps

Double OC12 service is designed for customers whose primary concern is additional bandwidth. For Double OC12, Systek provisions both OC12s to the same Systek high-speed hub, preferably the same router. Direct OC12 service is designed to accommodate customers concerned with redundancy. For Diverse OC12, Systek provisions the two OC12s to two separate hubs. When this is not possible, circuits are provisioned to separate routers within the same Systek hub.

Shadow OC12 service offers current Systek OC12 customers a redundant service option that provides anextra level of reliability. Shadow OC12 is used as an automatic backup connection if the primary OC12 experiences connection failure. If your primary connection should be unable to pass packets, the Shadow OC12 connection will handle your IP traffic.

Price Protected OC12 is provisioned as a full OC12 circuit (622 Mbps) with a single, fixed, monthly cost. This service is designed for businesses that require a full OC12 circuit on a sustained level. Price Protected OC12 service allows you to connect to the Systek's network via POS. The full circuit is always available and you always pay the same rate, regardless of how much bandwidth you use.