Network: The physical elements that comprise the network.
ATM Switches: The number of ATM switches a vendor has in its network. A larger number of switches implies better, more seamless coverage and faster connections.
ATM PoPs: The number of ATM points of presence a vendor has in its network. A larger number of PoPs implies better, more seamless coverage and faster connections.
Backbone: The bandwidth capacity of a vendor's backbone network. A higher number implies greater capacity. Among ATM vendors, capacities range from OC-192 (10 Gbps) in part of the network, to OC-48 (2.488 Gbps), to OC-12 (622.08 Mbps), to OC-3 (155.52 Mbps).
Platform: The primary switching equipment used in a vendor's ATM network. Different switching platforms provide different advantages and disadvantages, which are discussed elsewhere in the Current Analysis database.
Service: The different geographic and technical aspects of the service offered.
Service in Top 25 MSAs: Number of the top 25 metropolitan statistical areas in which a vendor offers service. Broader geographic coverage is a significant advantage, as most customers for ATM services are large enterprises with numerous locations.
Port Speeds:
Connections: Whether a vendor offers permanent virtual circuits, switched virtual circuits, or both. All major vendors offer permanent virtual circuits, which are dedicated around-the-clock to a customer's data needs. A switched virtual circuit, however, is set up and used only as long as data are being transmitted. An SVC may be a more economical option for companies that need data services that are limited in scale or time.
International Service: Whether a vendor offers ATM service outside the U.S., and if so, the regions or countries. Broader international coverage is a significant advantage, as most customers for ATM services are large enterprises with numerous locations.
Frame-ATM Internetworking: Whether the vendor offers data interworking between Frame Relay and ATM. This capability allows customers to transmit data using both protocols over a single network that uses ATM and Frame CPE at different locations, which is significant since many enterprises have both Frame and ATM CPE within their networks.
Performance Monitoring: Whether it is possible for a customer to monitor the performance of its ATM network online. This allows customers to judge the performance of their network in real time, which aids in the enforcement of SLAs, in the internal reporting of performance, and in the decision of whether or not to retain the data services vendor.
MPLS Support:
Inverse Muxing: Whether or not a vendor has inverse multiplexing capabilities. Inverse muxing (or imuxing) is a capability that allows for intermediate bandwidth between T-1 and T-3 (e.g., four T-1s at 1.5 Mbps = 6 Mbps).
Managed CPE Services: Whether a service provider offers to provide and maintain the equipment necessary for Frame Relay that is on the customer's premises. This capability can give the customer greater simplicity and lower bills because it would be doing business with a single company for ATM services.
Min. PVC Change Time: The minimum change time for permanent virtual circuits, as guaranteed by a company. Shorter change times give enterprises greater flexibility in adjusting their data needs.
Service Classes: Of the five methods of transmitting ATM data that are accepted by the ATM Standards Committee, the ones that are possible via a vendor's network. Bit rates include, in descending order of prioritycommitted bit rate, variable bit rate (real time), variable bit rate (non-real time), available bit rate, and unspecified bit rate.
ATM PVC to Internet: Whether a vendor offers ATM permanent virtual circuits that connect to the Internet, which allows for the transmission of ATM packets over the Internet.
Pricing: Although best of breed has traditionally been the primary influence over ATM service provider selection, pricing is growing in importance as ATM technology matures and competitors achieve parity on many service metrics.
Port Charge @ DS-1: The cost for using a port at DS-1 (1.544 Mbps) for a month.
Port Charge @ DS-3: The cost for using a port at DS-3 (45 Mbps) for a month.
Port Charge @ OC-3: The cost for using a port at OC-3 (155 Mbps) for a month.
Port Charge @ OC12c:
PVC Bandwidth CBR: The amount bandwidth costs per bit when transmitted at a constant bit rate over a permanent virtual circuit.
PVC Bandwidth VBR: The amount bandwidth costs per bit when transmitted at a variable bit rate over a permanent virtual circuit.
PVC Bandwidth UBR: The amount bandwidth costs per bit when transmitted at an undefined bit rate over a permanent virtual circuit.
Flat Rate or Usage: Whether a vendor offers ATM pricing based on a flat rate or usage, or both. Flat rates are most useful for customers that use ATM a great deal, while usage pricing may be advantageous for those that use it periodically.
Distance Sensitive Price: Whether a vendor offers pricing plans that are sensitive to distance traveled. Vendors with distance sensitive pricing generally have advantageous pricing for customers whose networks are primarily intraLATA.
SLAs Available: Whether a vendor offers service level agreements for its ATM service. SLAs are useful in that they provide a clear understanding between the provider and the customer as to what is expected, and credits are usually applied in cases where a vendor fails to meet SLA requirements.
PVC Delay (ms): A vendor's service level agreement for the average time it takes to receive data via an ATM permanent virtual circuit, in milliseconds.
Port Availability: A vendor's service level agreement for availability of ports.
On Time Provisioning:
Network Availability: A vendor's service level agreement for the availability of its ATM network.
Mean Time to Repair: A vendor's service level agreement for the average time it takes to resolve ATM problems and make appropriate repairs.
Data Delivery Rate CBR: A vendor's service level agreement for delivery of data via a committed bit rate. DDR is defined as the measure of the throughput of the data (just the payload, not the address information) that is presented to the Frame Relay network for transport. The closer the percentage is to 100%, the more complete the throughput is.
Data Delivery Rate:VBRnrt: A vendor's service level agreement for delivery of data via a variable bit rate (non-real time). VBR-nrt is a class of service whose rate varies by time of day, but may be used for real-time applications. The lower the number (expressed in milliseconds), the stronger the guarantee. DDR is defined as the measure of the throughput of the data (just the payload, not the address information) that is presented to the Frame Relay network for transport.
CBRNetwork Delay DS-3: A vendor's service level agreement for network delay at the DS-3 level (45 Mbps), under conditions of a constant bit rate, which is a fixed bit rate with data sent in a steady stream. CBR is generally used for real time applications, such as voice or video. The lower the number (expressed in milliseconds), the stronger the guarantee.
CBRNetwork Delay OC-3: A vendor's service level agreement for network delay, or time spent within the vendor's network, at the OC-3 level (155.52 Mbps) under conditions of a constant bit rate, which is a fixed bit rate with data sent in a steady stream. CBR is generally used for real time applications, such as voice or video. The lower the number (expressed in milliseconds), the stronger the guarantee.
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