|
|
|
|
|
|
|
|
|
Here is a brief introduction to the calculator. For
more detailed information, press the Help Button. For a
running record of the results calculated, press the Results
button. Both these functions open new browser windows on your
desktop.
- The Erlang B traffic model is used by telephone system
designers to estimate the number of lines required for PSTN
connections (CO trunks) or private wire connections. The
three variables involved are Busy Hour Traffic (BHT),
Blocking and Lines:
- Busy Hour Traffic (in Erlangs) is the number of hours
of call traffic there are during the busiest hour of operation
of a telephone system.
- Blocking is the failure of calls due to an
insufficient number of lines being available. E.g. 0.03
mean 3 calls blocked per 100 calls attempted.
- Lines is the number of lines in a trunk group.
- If you know two of the figures, you can work out the third as
follows:
- Click on the Unknown radio button representing the
unknown variable.
- Enter the 2 known figures into their edit boxes.
- Press Calc and the third figure will be calculated
and displayed in the remaining edit box.
- For example, if from your call logger, you know that the Busy
Hour Traffic is 10 Erlangs, and you want to know how many lines
are required in this trunk group if you are prepared to tolerate 2
calls being blocked in every 100 calls attempted then:
- Press the Lines Unknown radio button (this is
selected by default).
- Enter 10 in the BHT edit box.
- Enter 0.02 in the Blocking edit box.
- When you press the Calc button, 17 will be displayed
in the Lines edit box indicating that 17 lines would be
required in this trunk group.
|
|
|
|
The Erlang B Traffic Calculator on this page is
modelled on the Erlang B Calculator included with the Westbay
Traffic Calculators for Windows. The calculator works up to
25,000 Erlangs / Lines and has the ability to display and
print the results of any calculations you have made during the
previous week.
Customers also benefit from an Extended Erlang B
Calculator, an Erlang C Calculator for analysing call centres and a
Call Minutes Calculator. These calculators are available for 80 US
Dollars (54 Pounds Sterling GBP). If you pay using VISA, MasterCard,
American Express or Discovery, you can have this software
working on your PC in five minutes!
|
|
|
| Westplan is a revolutionary
software package which simplifies the complicated design process
involved in creating effective voice networks that are based on
either traditional circuit switching or Voice over IP. All
calculations are based on an inter-nodal traffic model which you can
specify yourself, or allow Westplan to estimate.
Westplan main
window, with a network drawing in view
By allowing you to try different network
topologies, Westplan quickly helps you to make informed judgements
on the suitability of particular voice networking strategies to your
company. You will be in a stronger position to understand your voice
network costs and therefore to control your network
resources.
Westplan supports these features:
- Point and click network
diagrams
- Voice over IP bandwidth
calculations
- Layer 2 support for PPP, Frame Relay,
Ethernet and ATM
- Analogue, T1 and E1 transmission
facilities
- User-definable routing rules
- RTP compression for VoIP
- Full justification reports for each
analysis
- Clear printed reports
- Context sensitive help
| |
