Network Bandwidth
Network bandwidth is the data rate that can be supported by your network connections and pipelines. Network bandwidth can refer to the theoretical limit or to the actual usage. Most often when people discuss network bandwidth they are talking about the perceived speed of their local area network, but network bandwidth alone does not measure speed. The latency, or delays in processing, associated with the network also affects the speed of the network. Network bandwidth monitoring can identify bottlenecks as well as underutilized pipelines and must be part of the planning process.
Network Bandwidth -- Capacity Planning
Another reason to monitor network bandwidth usage is for capacity planning. You need to know how network bandwidth usage fluctuates at different times of the day as well as from month to month if you are to make an informed decision about capacity growth or contraction.
Bandwidth planning requires that you evaluate two different metrics: the total bandwidth and the highest bursting bandwidth.
Total bandwidth is the total sum of all bandwidth consumed by all network devices on your LAN including servers, internet workstations, voice over IP applications, and video conferencing applications.
Highest bursting bandwidth is the total amount of predicable bursts that may occur. Bursts usually occur when a large amount of temporary data is transferred in or out of your network. A file transfer will produce an unpredictable burst during the time of transfer from one point to another. A 384 Kbps video call will be a constant, predictable amount of bandwidth consumption. When estimating bandwidth consumption for this application you can say that the bandwidth requirement for a 384 Kbps video connection will be 384 Kbps plus 20% overhead or 460 Kbps of maximum consumption during a call. Internet workstations, for example may consume only a very small amount of bandwidth if not transferring files, or receiving data.
This sample bandwidth-planning diagram shows this site using video, and data. For visual purposes each application is broken down into separate segments using two separate switches. Each segment has its own bandwidth requirements with 3.0 Mbps connectivity to the site.
If your sites data connection is provided by ITS Data Services, a data analysis can be requested to see whether the existing amount of bandwidth will suffice for all applications or whether more bandwidth is needed. If the data connection is not provided by ITS, the client must contact their Internet Service Provider for this information.
The following illustration is an actual data analysis of bandwidth usage at James Sprunt Community College during a single week. The Y coordinate at the left of the graph indicates the amount of bandwidth used. As you can see there are peaks that approach 90% of the maximum 1.544 Mbps. These peaks usually occur during the busiest part of the day.
ITS
Data Services offers several options for connectivity to your site.
A 1.544 Mbps (T-1), a 3 Mbps, and a 6 Mbps circuit upgrade is available to
link your site to the State owned network and the Internet. Additional, higher
bandwidth links are also available. It is important to plan your network
and consider the future needs of your campus or agency before ordering your
bandwidth upgrade. We find that many sites are pushing 90-100% utilization
of their maximum bandwidth on their current circuits. Cisco recommends
80% utilization or less. A typical campus network will have a mixture
of data, video, and voice traffic traversing their campus in the near future.
Correct planning can ensure that each site has enough bandwidth to handle
daily activities at peak traffic hours.
ITS Video Network Services (VNS) has spent many hours engineering circuit configurations that will provide optimum throughput and quality on voice, video, and data applications.
Some advantages of purchasing your connectivity from the State of NC, ITS:
1. The ability to configure your connectivity with Quality of Service.
2. State circuits are engineered for the fewest number of network hops.
3. 24 x 7 Helpdesk Support
4. Access by State ITS engineers to network equipment for monitoring and troubleshooting.
5. The ability to continually monitor your sites traffic to determine the percent of bandwidth utilization, or errors that may degrade quality.
6. Engineered and tested router hardware that provides the best configuration for video, voice, and data.
7. Our ability to expedite the repair of faulty lines and circuits that are managed by ITS Video Network Services.
Connectivity from Telcos and Internet Service Providers (ISPs)
Connectivity and bandwidth planning must also be accomplished when connectivity is ordered from independent ISPs or telephone companies. For video conferencing to be successful, all LAN configurations and conditions recommended in this document must also apply to circuits ordered through Telcos and ISPs.
It is crucial to provision your circuit with enough bandwidth incoming and outgoing to handle all of your site’s video, voice, and data applications, and to allow for a reasonable amount of growth.
Typically an independent provider will not offer or guarantee any type of Quality of Service. All incoming traffic from an independent ISP will enter the state network and be tagged as best effort. If the incoming packets from the ISP contain errors, the errors will be carried through the state network.
Know what you are buying. Independent providers offer many different configurations when selling network connectivity. They offer both symmetrical and non-symmetrical bandwidth, depending on your site’s requirements. Usually non-symmetrical connectivity is less expensive. Symmetrical bandwidth is defined as the same amount of bandwidth incoming and outgoing at your site. This is referred to as the uplink and downlink. An example of a symmetrically provisioned circuit is a circuit with 768 Kbps Up and 768 Kbps Down. An example of Non-symmetrical provisioning can be 768 Kbps UP and 1.544 Mbps Down. It is crucial that a data analysis of your requirements both ways be accomplished to avoid costly errors in when ordering connectivity directly from an independent provider.
ITS Video Network Services (VNS) has spent many hours engineering circuit configurations that will provide optimum throughput and quality on voice, video, and data applications.
Some advantages of purchasing your connectivity from the State of NC, ITS:
1. The ability to configure your connectivity with Quality of Service.
2. State circuits are engineered for the fewest number of network hops.
3. 24 x 7 Helpdesk Support
4. Access by State ITS engineers to network equipment for monitoring and troubleshooting.
5. The ability to continually monitor your sites traffic to determine the percent of bandwidth utilization, or errors that may degrade quality.
6. Engineered and tested router hardware that provides the best configuration for video, voice, and data.
7. Our ability to expedite the repair of faulty lines and circuits that are managed by ITS Video Network Services.
Connectivity from Telcos and Internet Service Providers (ISPs)
Connectivity and bandwidth planning must also be accomplished when connectivity is ordered from independent ISPs or telephone companies. For video conferencing to be successful, all LAN configurations and conditions recommended in this document must also apply to circuits ordered through Telcos and ISPs.
It is crucial to provision your circuit with enough bandwidth incoming and outgoing to handle all of your site’s video, voice, and data applications, and to allow for a reasonable amount of growth.
Typically an independent provider will not offer or guarantee any type of Quality of Service. All incoming traffic from an independent ISP will enter the state network and be tagged as best effort. If the incoming packets from the ISP contain errors, the errors will be carried through the state network.
Know what you are buying. Independent providers offer many different configurations when selling network connectivity. They offer both symmetrical and non-symmetrical bandwidth, depending on your site’s requirements. Usually non-symmetrical connectivity is less expensive. Symmetrical bandwidth is defined as the same amount of bandwidth incoming and outgoing at your site. This is referred to as the uplink and downlink. An example of a symmetrically provisioned circuit is a circuit with 768 Kbps Up and 768 Kbps Down. An example of Non-symmetrical provisioning can be 768 Kbps UP and 1.544 Mbps Down. It is crucial that a data analysis of your requirements both ways be accomplished to avoid costly errors in when ordering connectivity directly from an independent provider.