The document discusses the benefits of a private voice-data telecom network (PVDTN) system. It outlines how PVDTN can save organizations up to 75% of present telecom costs, improve decision making and security, and virtually convert multi-location organizations into single offices. The document provides diagrams illustrating sample network configurations and topologies that can be implemented using PVDTN to integrate voice, fax and data communications across locations.

1. PRIVATE VOICE - DATA TELECOM NETWORK
“A BUSINESS TOOL YOU CANNOT AFFORD TO BE WITHOUT”
• 100% secure, fixed operating cost, • Cuts present telecom costs
private network. by up to 75%.
• No usage charge. • Unlimited inter-locational
communications - speech, fax, data.
• Set-up cost pay back
in 1 to 2 years • High network up-times.
• Ideal communications backbone
for ERP
DELHI KOLKATA
• Voice and voice-data conferencing.
MUMBAI • Integrates voice, fax, data over
analogue and digital leased lines.
• Connects any place in the world.
• Group III fax - no time lost in
document scanning.
• Set-up cost - 50 to 60% of conventional CHENNAI • Normal telephone type
digital leased line solutions; 25% of PAMA speech - no delay or
VSAT solution. distortions.
• Annual operating cost - 75 to 80% of • Eliminates STD calls between
conventional digital leased line solution; Company locations.
20 to 25% of PAMA VSAT solution.
• Converts MLOs to VSOs
• Break-even duration - 25 minutes of additive communications from both sides of a link, for all types of communications
taken together, speech, fax, data.
• Patent 176287 of 27.12.1991
•Patent 202674 of 23.10.1998
&
New Patent Pending
6/1A, KARTIK BOSE LANE, KOLKATA - 700006.
Phone: 91332543-3684; FAX: 91332543-3684
Mobile phone : +919432228808 / +919831210647
e-mail : midautel@bsnl.in

2. Fig 1
PVDTN NODE ARCHITECTURE
LINE SPLITTER – KM2100
Trunk line cards KDI
Digital n x 64 KBPS
Leased Lines Voice / fax cards KVF.8
From Delhi Data cards KHS.2 / KLS.1
From Nagpur
From Mumbai
From Chennai
Analogue
Leased Lines
From locations in same city
or outstation location
Tel
V
D
P
S
Fax
LCE 2W E&M IP Router
Circuit switch router
Modem Server
Residential Connection
LAN BUS
LAN Nodes
NOTE: In Kolkata there are no 4WE&M analogue lines terminating on the VDPS
trunk cards. However, these have been shown so that the analogue
connection at Mumbai from Ahmedabad and at Delhi from the CG Cell
may be understood.
2WE&M lines shown will be present in all locations for residential
connections.

3. Fig 2
TYPICAL STATE WAN CONFIG
USING MULTI-TIER PVDTN
FOR INTEGRATED VOICE, FAX, DATA COMMUNICATIONS
UP TO GRAM PANCHAYAT
WITH 100% ALTERNATE ROUTING / REDUNDANCY
6.22 KBPS
62.42 KBPS 2 2 2
1 1 1 1
2 X 128 KBPS 2
1
320.7 KBPS 2 1
3
3 1
3 3 3 3
2 X 2WE&M 1
1
6 6
6
384 KBPS 6
4 4
3 6 4
4
3 4
768 KBPS 8
4
3
8
4 8
8 4
4 8
2 MBPS
4
1958.6 KBPS 8 4 MBPS
4 8
4
8 KOLKATA
8
4 8
4
8 4
8
4
8 4
8
8
8 8
4 8 4 MBPS
4
2 MBPS 4
4
4 4
4 4 4 4
NOTE : Total number of trunks emanating from Kolkata is 144 (8 x 18). Using the Erlang loading
norm this can serve 1152 extensions in Kolkata. Thus 1158 officers may be provided NET
telephones and they may be spread across Writers’ Building, New Secretariat, and the Secretariats
at Salt Lake

4. Fig 3
CII – PVDTN
Single Tier Network
WIDE AREA NETWORK TOPOLOGY
Chandigarh
3 512 KBPS IHC
140.64
4 KBPS
9 4 192 KBPS
120.96
KBPS 6 Delhi
320 KBPS 7
227.2
Gurgaon 6 9
KBPS
300.40
KBPS 6
5 103.76
256 KBPS
118.48 KBPS
KBPS
6
128 KBPS 3
2 Kolkata
3
3 110.64
Mumbai
KBPS
3 Hyderabad
6
3
120.96
Bangalore 3 KBPS

5. Fig 4
TRI-
TRI-NODE FORMATION
IN PVDTN
USED FOR SINGLE AND MULTI-TIER NETWORKS
MULTI-
X
MAX (X,Y) Y
A
B
X+Y
X+Y
C
1. X and Y are the total bandwidth impinged on the WAN at each location
at A and B respectively. This includes bandwidth for data, speech, and
fax communications.
2. The derivation of X and Y at each location is shown in Table I of our
draft proposal presentation.
3. The link bandwidth calculations are shown in Table II of draft proposal
presentation. As shown above the main links AC and BC will have a
total bandwidth of X + Y. This is to take care of 100% alternate routing
in case of failure of either AC or BC links.
4. The cross link AB will have the larger of the two bandwidths X,Y.
5. We hope this will help you to understand the basis of derivation of
location and link bandwidths shown in our draft proposal presentation.

6. Fig 5
Schematic Diagram of STS
Storage
INTERNET PS
STS IS
INTRANET CS
•PS, IS, CS have same fields which are synchronised at each
connection.
•CS collates data from internal data bases to pass on to PS
through IS, and also distributes information received from the
interactive Web pages in the PS to the relevant data base.
•The information stored in the Storage associated with the PS
helps to carry out e-commerce activity like placing orders, internet
banking. Etc. The storage is updated in each STS cycle.

7. Fig 6
Switching arrangement of
STS
Public Server
Company For Company information,
Company information Inter-active Web pages
data bases and and
mail server Internet mail Gateway
DB1 DB2 CS PS
Company LAN 0 Internet LAN
1 2
3-Pos Electro-mechanical
RJ45 switch
Intermediate Server
For transferring information
and mail back and forth
Between CS and PS
(IS)
Switch changes state on
CL IL Automated settable commands
I/O I/O from software in IS
Box Box
0
1 2
3-Pos EM RJ45
Switch
State changes
With manual command
From Node
Nodes for
Internet browsing

8. Fig 7 – Overall datagram
CS IS PS
Company Info
Web Info
Company
External mail
Fig 8
Step 1 – IS connected to CS
CS IS PS
Changes in
Company Info Company
Info received
Changes in
Web Info Web
Info received
Incoming Outgoing
Company Mail Mail
External mail received received
Fig9
Step 2 – IS in Null after connecting to CS
CS IS PS
Changes in
Company Info Company
Info received
Web Info
Outgoing
Company Mail
External mail received
All content
In IS cleansed
For viruses etc

9. Fig 10
Step 3 – IS connected to PS
CS IS PS
Changes in
Company Info Company
Info received
Changes in
Web Info Web
Info received
Incoming Outgoing
Company Mail Mail
External mail received received
Fig 11
Step 4 – IS in Null after connecting to PS
CS IS PS
Company Info
Changes in
Web Info Web
Info received
Incoming
Company Mail
External mail received
All content
In IS
Cleansed for
Viruses, etc.

10. Summarising, our patented business tool
PVDTN can give your organisation the
following benefits.
Saves around 75% of your present
telecom costs.
Saves a substantial portion of your inter-
locational travelling costs and time.
Speeds up decision making.
Ensures 100% security of your internal
data bases.
Converts your MLO (multi-locational
organisation) into a VSO (virtual single
office).
Facilitates e-Commerce through a Public
server connected to the Internet and the
STS system

11. To convert your present voice and data
communications infrastructure into a PVDTN the
following steps are required.
The present LANs in each location will be
connected to the integrated PVDTN WAN through
routers and the channel splitter
A separate Internet LAN will be provided for
connecting the Public server (central location only)
and internet browsing nodes (at all locations).
The present voice / fax LAN through the existing
EPABX will continue to be used for communications
with organisation outsiders through the PSTN
(public switched telephone network)..
A separate voice / fax LAN will be set up at each
location and connected to the PVDTN WAN through
the VDPS (EPAX with E&M trunks) and the channel
splitter.
The present data WAN connectivity will be changed
to point-to-point leased lines in tri-node
configuration or with redundant links for alternate
routing..
There will be no disturbance to the existing network
till the PVDTN WAN / LAN is ready for a smooth
and quick cutover

12. ADDITIONAL INFRASTRUCTURE FOR PVDTN
AT CENTRAL LOCATION
Existing infrastructure
PSTN Additional infrastructure
EPABX VDPS
Channel
LAN LAN splitter
PS CS
INTERNET INTRANET
LAN LAN
S
S Secure Switch
IS
S
S PVDTN
INTERNET WAN
IBN

13. ADDITIONAL INFRASTRUCTURE FOR PVDTN
AT OTHER LOCATION
Existing infrastructure
PSTN Additional infrastructure
EPABX VDPS
Channel
LAN LAN splitter
IBN
S
S
INTERNET INTRANET
LAN LAN
S
S
IBN PVDTN
INTERNET WAN

14. Fig.12
NIB – II
Srinagar TOPOLOGY
Shimla
Chandigarh
IGW
Delhi
Noida Noida
Jaipur
Guwahati
Lucknow
Patna
Gandhinagar / Ahmedabad
Bhopal
Mumbai Kolkata
BRAS
Chattisgarh IGW
IGW
Kolkata
Mumbai
H-bad
IGW Pune BRAS
Bhubaneshwar
IGW
Goa
Bangalore
Chennai
Bangalore
IGW
Chennai
IGW
Pondicherry
Back Office facilities – Web hosting,
Customer servers, Messaging, Caching,
Ernakulam Billing, etc.
IGW CORE Router
EDGE Router
BRAS
STM16
Thiruvanthapuram
STM1

15. Fig. 13
NIB – II
ARCHITECTURE
DIAL – UP
CONNECTIONS TO OTHER CORE ROUTERS
NATIONAL INTERNET
EXCHANGE
TO CONNECT
PSTN NETWORK ALL ISPs AND PROVIDE
COMMON
INTERNATIONAL
GATEWAY
CORE ROUTER
RAS
DIAL – UP EDGE ROUTERS NIEX
SERVICE EDGE ROUTERS EDGE ROUTER
EDGE
ROUTER TIER I
BRAS BRAS BRAS BRAS
EDGE ROUTERS EDGE ROUTERS EDGE ROUTERS EDGE ROUTERS
MPLS VPN
EDGE ROUTERS
TIER II TIER II TIER II TIER II TIER II TIER II EDGE ROUTER
TIER II TIER II TIER II TIER II
DSLAMs
DSLAMs
Leased Lines from VPN Subscriber Premises

16. Explanatory Notes on VPN Vulnerability
Slide 1 shows the topology of a typical ISP’s IP
network over which both Internet and VPN
services are laid out. This is the topology of
BSNL’s NIB – ii. Five cities are connected in a
full mesh connectivity to form the core IP back-
bone across India. Other cities are connected
through tri-node rings from the nodes of the
core network through the Tier-1 switch at
these nodes.
Slide 2 shows the architecture of each of these
nodes. The core router at the node sits on the
Tier 1 switch. From these switches are taken
the router connections for all the services –
VPN, Internet through Broadband and PSTN.
Thus you will note that there is continuous
physical connectivity between all the routers in
this IP network through the Tier 1 switch at
each IP Node (POP). Thus there is continuous
public domain access to the VPN routers.

17. 1. In any IP network, public or private, the WAN ports of all
routers in the network have continuous physical access
to each other. Thus while a router port is engaged in
communication with another in the network, a third port
can have simultaneous communications with it. If the IP
network is in the public domain (Internet) or has access
from the public domain (VPN), this third port could be
that of a hacker.
2. Thus while the various security protocols like IP Sec,
etc., can transport the data from one computer to
another securely, the LAN and the data bases residing
on it are exposed to public domain through a VPN
which has public domain access for reasons explained
in 1 above.
3. For WAN computing it is necessary to have a real
private network (at least for data communications).
Once this is there then inter-locational voice / fax can be
run over this network at marginal increase in the
operating cost, using the patented PVDTN system.
4. You should not expose your company data bases to the
public domain through Internet, ISDN back-up, or VPN
(which has public domain access) for reasons explained
earlier in 1 above.
5. The MPLS networks currently in vogue are another form
of VPN network and are subject to the comments in 1 to
4 above.

18. We do hope the above notes will
explain the security vulnerability of
your data bases when these are on
LANs connected to VPN (MPLS or
other wise) of any service provider.
If you wish to secure your data
bases 100% then use point-to-point
leased lines for inter- locational
computer connectivity.