Hands-On Design Process for Voice Networks. 1. Model Voice Grade (VG), 56-Kbps & T-1 Leased lines 2. Model 1, 2 & 3 Optimally-Located SWs 3. Model leased lines and virtual lines by using ECC values of 13.33 and 1.00.
1. Model Voice Grade (VG), 56-Kbps & T-1 Leased lines
2. Model 1, 2 & 3 Optimally-Located SWs
3. Model leased lines and virtual lines by using ECC values of 13.33 and 1.00.
4. The above tasks are executed for an hypothetical enterprise (let us name it Hi-Tech) that consists of 17 sites with headquarters in Las Colinas, Texas. These 17 sites are served by two legacy voice and data networks (separate and distinct).
Existing network employs leased voice grade (VG) lines. Each VG line can handle either 1 conversation or 9600 bps data rate.
The specifications for the VGLs (and for 56 Kbps, T-1 and T-3 lines) are defined in the enclosed NLT input file.
5. The existing networks employ a voice switch and a data switch (FE + Host), both located at Las Colinas.
6. In order to understand the design of VoIP networks, one must first understand the design of legacy voice and data networks.
7. The design data for existing networks is provided in input files, FILES, VHD17, NLT and SDF.
8. We will describe the design process and design parameters first for the voice networks and then later for the data networks. Later we will first design an integrated V/D network using CS technology (using TDM technique) and later we will design a VoIP using IP/PS technologies.
The Overall Design Process
Prepare a VHD file using the CPE data
Prepare a NLT file for useful link types
Select the valid tariffs in a TARIFF file
Prepare a valid LINK file if required
Use the “Find
SW locations for creating
Adjust the SDF design parameters
(=AL Type Per the LINK file)
TKLT=TK Link Type for voice/data networks
(Blocking allowed on
the amount of inter-nodal traffic flowing on
trunks for the case nodal
TCA BHR traffic
intensities are used for modeling a network.)
. Cost of a 5-Min Call
Factors ALMF and TKMF as defined in NLT
=0, one obtains a
voice network with all
single type determined by ALT
=1, one obtains a
voice network with a mix of AL
types as determined by the values
of the LINK file named in FILES.
• TGF must = 1 for all runs.
1. Open/View the input file “Files” and enter VHD17, LINK17, MAPusa, TARIFF, SDF, NAME17, LATA17 and SWF in the proper cells and UPDATE.
2. Open/View the input file “SDF” and update values of ALT=1, TKLT=1, Bal=0.1, Btk= 0.1, ECC=13.33 (leased lines only), ALMF=1 and TKMF=1 for leased VG lines.
3. Run FindCOG and compute the opt. location of 1 SW at 1, 2 SWs at 1, 11 and 3 SWs at 1, 11, 2. (Explain why?)
4. Use SWF with 1 SW at 1, 2 SWs at 1 and 11, 3 SWs at 1, 11 and 2 to create three VoiceNets.
5. Repeat Steps#2, 4 for ALT=2, TKLT=2 and ECC=13.33 (leased line only) to crreate 3 more VoiceNets
6. Repeat Steps#2 and 4 for ALT=3, TKLT=3 and ECC=13.33 (for leased lines only) to create 3 more VoiceNets.
7. Now we have 9 VoiceNet topologies. Repeate the Steps#2, 4, 5, 6 with ECC=1 (I.e. modeling $1.0 for a 5-Min call on the virtual public network. We now have a total of 18 VoiceNet topologies.
8. Tabulate results to find the Optimum VoiceNet topology. Add Remarks.
9. For the optimum VoiceNet, tabulate the total transmission costs versus Bal/Btk. Make some observations about the optimum network.
10. Considering the 18 VoiceNets, find the ones which are hybrid networks (i.e. using a mixture of leased lines and virtual lines). Hint: Study the output files and find sites served by either leased lines or virtual facilities.
1. Create a MSWord document with tabulation of 18 VoiceNets with your own remarks.
2. Include a DBF Output file for the Optimum VoiceNet.
3. Include the tabulation of Total Monthly Costs for Optimum net Versus Bal/Btk with observations about the optimum VoiceNet
4. Include a TKF for the Optimum VoiceNet and check values in original traffic and modified-traffic matrices.