|Max Busy Hour||Avg. Busy Hour|
|Max Busy Hour Bandwidth||Avg. Busy Hour Bandwidth|
|Max Busy Hour||Avg. Busy Hour|
The InfoPlus Aggregate Bandwidth Tool allows you to easily determine how much network bandwidth your Communication Server voice traffic may contribute to your data network. Because the data network is a shared facility, one cannot simply sum the maximum bandwidth requirements of individual Trunk Groups or Route Patterns to determine the impact on the WAN. If multiple sources of traffic are being sent over the WAN, that activity must be combined at a low level before performing traditional traffic engineering calculations to determine the busy hour requirements. This tool allows you to select the sources of voice traffic that will be carried over a shared facility, and calculate the bandwidth requirements of that combined traffic using the actual data collected during an InfoPlus Traffic Study.
To get started right away:
Select the desired sources of voice traffic from the Aggregate Sources panel to the left.
Select the desired VoIP Codec parameters from the Codec panel on the bottom.
Hit the Generate Analysis button at the bottom of the screen.
Click on the additional headings below to learn more.
As an example for using this tool, consider a Communication Server that currently has two traditional TIE facilities to carry on-network traffic to two different branch offices. In preparation for a move to SIP trunking, one could measure the amount of voice traffic on each of these facilities independently, and determine the bandwidth required to handle the equivalent VoIP traffic during the busiest hours. For demonstration purposes, assume that both TIE facilities would require 1 Gbps of bandwidth to carry the VoIP traffic during their busy hour. If both facilities would be sharing a WAN connection, one might assume that 2 Gbps of bandwidth would be required on the WAN to handle the traffic from the two TIE facilities. However, if the facilities are not busy as the same time of day, this would be a gross over-estimation, as can be seen when the traffic is summed on an hourly basis.
Initially, the tool will display the possible sources of voice traffic in the Aggregate Sources panel to the left. You may select either Trunk Groups (Routes) or Route Patterns/Lists as the source of traffic. Please note that when measuring Route Patterns/Lists, only outgoing traffic is considered, as incoming calls are not handled by Route Patterns. To include the measured traffic of a source in the aggregate calculation, click the checkbox next to the source. Once enabled, you may optionally choose a percentage of the source's traffic to consider, which is helpful if less than 100% of the source's traffic will be transitioned to the WAN. The aggregate bandwidth calculations will be based on the sum of the measured traffic from each of the selected sources.
To further customize the analysis, you can alter the settings in the Analysis Criteria panel at the bottom of the window. You can restrict the timeframe of the traffic measurements included in the analysis by updating the dates and times in the Timeframe section. The settings in the Codec section determine the assumed per-call bandwidth. In addition to selecting a Codec and Sample Size, you can define the amount of 'Layer 2' network overhead to include by selecting a link type, and whether or not to include an estimated 35% reduction in bandwidth for using Voice Activation Detection (VAD), also known as Silence Suppression. For those with MPLS WANs, you can include the additional MPLS overhead in the bandwidth calculations by configuring the number of MPLS labels that will be added to packets by your Label Edge Router (LER). Finally, you can incorporate broad assumptions about the expected growth of traffic in the future, or add a conservative engineering margin by altering the Overall Growth slider.
Once the proper sources of traffic and analysis criteria have been selected, click the Generate Analysis button at the bottom of the screen to view the bandwidth calculations for the aggregate traffic. At any time you may modify the parameters and hit 'Generate Analysis' to refresh the results. When viewing the current analysis, select 'Instructions' at the bottom of the analysis window to return to this screen, or select 'Print Version' to display a copy of the current analysis suitable for printing to a color printer.
The resulting aggregate bandwidth analysis is organized into three sections:
• Peak Bandwidth Engineering - This section calculates the peak bandwidth requirements for carrying the aggregated voice traffic. First, the Maximum Busy Hour and Average Bouncing Busy Hour traffic for the combined sources is determined. For each of these measurements, the maximum number of concurrent conversations is calculated for two different grades of service - P.01 and P.10 - resulting in four values. It is recommended to engineer for a P.01 Grade of Service if there are no alternate fallback facilities (e.g. a traditional TDM route) for the voice traffic. If there is an alternate facility to carry the traffic, you may want to engineer for a less aggressive P.10 Grade of Service to reduce costs. Then, the bandwidth consumed by a single call is calculated using the Codec parameters selected. Finally, this is multiplied by the maximum number of concurrent conversations to yield the peak bandwidth required.
• Average Busy Hour Bandwidth - Within an hour, the bandwidth requirements fluctuate as the number of concurrent calls increases and decreases. Whereas the previous section calculated the bandwidth requirements during the peaks of activity, this section presents the average bandwidth that would be consumed by the traffic during the busiest hours of the analysis. This is done by assuming the traffic occurred perfectly evenly throughout the hour, and determining how many fully-utilized connections would be required to carry the traffic. This produces the bandwidth that can be assumed to be used at any given moment during your busiest hours. So, when designing a facility to carry this traffic, it needs to have sufficient capacity to carry this bandwidth continuously throughout the busiest hours, as well as the ability to handle the peak bandwidth from the previous section during the absolute busiest moments.
• Average Daily Bandwidth by Hour - This section displays a chart of the bandwidth requirements throughout an average day during the analysis period. Each hour of the graph represents the average usage during that hour over the measured period. The blue bars correspond to the peak bandwidth requirements for the hour, as explained in the Peak Bandwidth Engineering section, using a P.01 Grade of Service. The red line shows the average continuous bandwidth during the hour, as described in the Average Busy Hour Bandwidth section.