Hands-On Design Process

1
Hands-On Design Process
for Data Networks
1. Model only 9600 BPS lines for ALs since 56000
BPS lines are too costly for the traffic loads
considered 2. Model 1, 2, 3 Optimally-Located
SWs for both MD and Star Topologies
2
DATA NETWORKS
The Design Process

Prepare
aVHD
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 Find
COGs
capability for choosing
Nsw
SW locations for preparing a valid
SWF
(
Fix NDEC DECT in SDF for
COGs
)

Adjust the required SDF parameters
3
SDF - The Data-Related
Design Parameters

ATP
(
Tr
analysis type), Wm, ALT, TKLT

UPR,HPR,HTT,
R
,
T
,
T
,
K
mph
np
hm
pg

IML, RML, BLKL, ICPB
(
Inf. bytes
./block)

N
(no. of nodes allowed/ VMPT valid for only
Doelz networks), MTKU, TGF
cu


F
0 or 1 (for use of Sharmas exchange
opt

algorithm for additional optimization)
4
Parameters ATP, Wm Values Allowed
 


ATP 1 implies an
async
protocol
(
)
e.g.
Burrough
, Frame relay, FPS, ATM

ATP 2 implies an
Doelzs
VMPT
FPS (
for superimposed BSC
netlinks
)

ATP3 implies SNA BSC protocol
(
)
e.g. polling of N controllers on a
netlink
ATP4 implies an X.25 protocol Wm must be lt
link-capacity per NLT

5
Parametrs UPR, HPR, HTT, Tnp, Thp,Tpg
1. UPR, HPR are SL rates usually less the AL
C. 2. HTT (host think time) generally about 1-10
sec. 3. Rmph applies to Doelz Networks Ignored
here 4. Tnp (nodal processing time) switch
time/msg. 5. Thm (half modem time) generally lt 5
ms. 6. Tpg (propagation delay time) about .01
sec/mi
6
ParamsIML, RML, BLKL, ICPB, MTKU
1. IML (inp. msg. length in bytes) Protocol
dependent 2. RML (response msg. Length in
bytes) same as above 3. BLKL (block length)
packet or cell size in bytes 4. ICPB
(information bytes per block/packet/cell) 5.
MKTU (max. trunk utilization) It must be less
than unity (or 1) since it determines the
available data rate on the trunks.
7
Design Parameters
(Contd)

Flk
0
StarData
Networks with with one
ALT-type as defined by ALT of SDF

Flk
1
StarData
Networks designed
with an hierarchy of concentrators as
determined by the LINK-file entries.

Flk
1 and FVC01 yields a 2-level Star-
Data Network with a mix of AL-types as
defined by the LINK file connecting all
the
CPEs
8
Design Parameters (Contd)

Flk
0
DLNets
and
MDNets
are
designed with one AL-TypeALT

Flk
1
DLNets
and
MDNets
are
designed with an hierarchy of
concentrators/
ALs
as determined by
the LINK file entries

MSTNets
are always designed with a
single AL typeALT
Wm
Infinity
9
Data Network Design Process
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 ALT1, TKLT1, for



leased 9600 BPS lines, ATP3 for BSC protocol, Wm
6300 bps BBTF2.
10
3. Also use UPR/HPR9600bps, IML28, RML300
bytes, Tnp10 ms, Thm4 ms, Tpg .01 ms/mi,
TGF1, Flk0, Fflt0
4. Use
SWF
with 1 SW at 1, 2
SWs
at 1
and 11, 3
SWs
at 1, 11 and 2 to create
three
DataNets with MD topology
.
5. Repeat Steps4 to model DataNets based on Star
topology. 6. Tabulate results with REMARKS.


11
7. Choose the optimum network topology based on
your criteria (cost or response time) 8. For the
optimum DataNet selected, plot total costs and Tr
(response time) in the range 500 ltWm lt9500 bps.
Wm is defined in the NLT input file, for each
link type. Plot the results. Make some cogent
observations.
12
DataNet Assignments
1. Add to the MSWord document a Result-
Tabulation of 6 DataNets with your own original
remarks. 2. Include a DBF for the Optimum
DataNet 3. Include the tabulation of Total
Monthly Costs and Tr for Optimum DataNet Versus
Wm with observations about the optimum DataNet